Crown Audio Stereo Amplifier 133472 1A User Manual

Amplifier Application Guide  
© 2006 by Crown Audio® Inc., 1718 W. Mishawaka Rd., Elkhart, IN 46517-9439 U.S.A.  
Telephone: 574-294-8000. Fax: 574-294-8329.  
Trademark Notice: Amcron®, BCA®, and Crown®, Crown Audio, IOC®, IQ System®, ODEP® and  
VZ® are registered trademarks and Grounded Bridge™, PIP™ and PIP2™ are trademarks of  
Crown Audio, Inc.  
Other trademarks are the property of their respective owners.  
133472-1A  
1/06  
 
3
Table of Contents  
Introduction.................................................................................................. 4  
Chapter 1: Crown Amplifiers In-Depth....................................................... 5  
1.1 Rack Cooling..................................................................................... 5  
1.1.1 Fan-Assisted Models................................................................. 5  
1.1.2 Convection-Only Models........................................................... 6  
1.2 System Wiring ................................................................................... 7  
1.2.1 Input Wiring............................................................................... 7  
Input Connector Wiring ................................................................. 7  
Balanced, Grounded Source ........................................................ 7  
Balanced, Floating Source ........................................................... 7  
Unbalanced, Grounded Source, Twin-Lead Shielded Cable ......... 8  
Unbalanced, Floating Source, Twin-Lead Shielded Cable ............ 8  
Unbalanced, Grounded Source, Single-Conductor  
Coax or Twisted-Pair Cable......................................................... 8  
Unbalanced, Floating Source, Single-Conductor  
Coax or Twisted-Pair Cable......................................................... 8  
1.2.2 Solving Input Problems ............................................................. 9  
1.3 Output Wiring .................................................................................. 10  
1.3.1 Output Connector Wiring......................................................... 10  
5-Way Binding Post..................................................................... 10  
Barrier Block................................................................................ 11  
Neutrik® Speakon® ...................................................................... 11  
1.3.2 Amplifier Load Impedance ..................................................... 13  
1.3.3 Determining Appropriate Speaker Wire Gauge....................... 14  
1.3.4 Loudspeaker Protection .......................................................... 15  
1.3.5 Solving Output Problems ........................................................ 16  
High-Frequency Oscillations ....................................................... 16  
Sub-Sonic Currents..................................................................... 16  
1.3.6 Distributed Speaker Systems.................................................. 17  
What is Constant Voltage?.......................................................... 17  
Transformer Saturation................................................................ 17  
1.4 Multi-way Systems (with Expansion Modules) ................................ 18  
1.4.1 Active vs. Passive Crossover Networks .................................. 18  
1.5 Fault Monitoring .............................................................................. 20  
1.6 Setting System Gain Structure........................................................ 21  
1.6.1 System Levels......................................................................... 21  
1.6.2 Amplifier Level......................................................................... 21  
Chapter 2:Troubleshooting ...................................................................... 23  
2.1 No Power......................................................................................... 24  
2.2 No Sound ........................................................................................ 25  
2.3 Bad Sound ...................................................................................... 26  
2.4 Amp Overheating ............................................................................ 26  
Chapter 3: Glossary of Terms................................................................... 27  
Appendix: Suggested Reading ............................................................... 33  
Amplifier Application Guide  
 
4
Introduction  
This application guide provides useful information designed to help you best  
use your new Crown® amplifier. It is designed to complement your amplifier’s  
Operation Manual, which describes the specific features and specifications  
of your amplifier. Helpful guides and tips on subjects such as system wiring  
and system gain structure, for example, should be helpful to you whether you  
are a beginner or a seasoned professional.You can choose to read this guide  
from cover to cover, or if you are already familiar with Crown amps, you can  
jump to specific sections as needed. A glossary of terms and list of suggested  
publications for further reading are also provided for your convenience.  
Please be sure to read all instructions, warnings and cautions.  
For your protection, please send in the warranty registration card today. And  
save your bill of sale—it’s your official proof of purchase.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
5
Chapter  
Crown Amplifiers In-Depth  
1
In This Chapter  
• Rack Cooling  
• System Wiring  
• Amplifier Load Impedance  
• Multi-Way Systems  
• Distributed Speaker Systems  
• Setting System Gain Structure  
his chapter provides information to help you get optimum performance  
Tfrom your Crown amplifier. It is a collection of techniques that can help  
you avoid many of the common problems that plague sound systems. For  
further study on many of these topics, refer to the recommended publications  
listed in the Appendix.  
1.1 Rack Cooling  
When installing your Crown amp in a rack, you should take steps to make  
sure that the temperature of the rack stays in a safe range. Crown amps with  
fan-assisted cooling and convection-only cooling may require different tech-  
niques for best performance.  
When designing your rack  
cooling system, you should  
consider the requirements  
for all mounted components.  
Figure 1.1  
Top View of Rack-  
Mounted Amplifier with  
Side Vents  
1.1.1 Fan-Assisted  
Models  
If your Crown amplifier uses  
fan-assisted cooling, make  
sure that the front vents and/  
or filters are never blocked,  
and that the exhaust fan  
(vented out the back or  
Amplifier Application Guide  
 
6
Chapter 1: Crown Amplifiers In-Depth  
sides) is not blocked or covered by cables. Also, if your  
Crown amp has foam filters, they can be cleaned with mild  
dish detergent and water when needed.  
Overheating  
Because of the wide range of operating  
conditions your amplifer might be sub-  
jected to in the field, you should con-  
sider each installation independently to  
ensure the best thermal performance.  
If your amp starts to overheat, consider  
the following possible causes:  
The side walls of the rack should be at least 2 inches (5  
cm) away from the chassis for amps with side venting as  
shown in Figure 1.1.  
Don’t use vented spacer panels between amps in a rack.  
Because of the airflow technology we use in our amps,  
it is best to stack multiple amplifiers on top of each other  
with no space between.  
1. Insufficient air movement.  
The amplifier draws fresh air into the front of the amp  
and exhausts it either out the sides and into the rack, or  
out the back depending on the model. We want the hot  
air that’s in the rack to vent out the sides or back—not  
the front. If any of these amplifiers are spaced apart with  
vented panels, some of the preheated air will recycle to  
the front of the rack and back into the amplifier. The result  
2. Overdriving of the input stage  
(severely into clip).  
3. Very low-impedance loads.  
4. High ambient temperatures.  
is loss of thermal headroom. If you choose to place the amplifiers with space  
between them, then use solid panels between them, not vented panels.  
You should provide adequate airflow within the rack. Additional air flow may  
be required when driving low impedance loads at consistently high output  
levels or for higher power models. Refer to your Crown amplifier’s Operation  
Manual for detailed information on ther-  
mal dissipation.  
Figure 1.2  
Extra Cooling with a  
Rack-Mounted Blower  
If your rack has a front door that could  
block air flow to the amplifier’s air  
intakes, you must provide adequate air  
flow by installing a grille in the door or  
by pressurizing the air behind the door.  
Wire grilles are recommended over  
perforated panels because they tend  
to cause less air restriction. A good  
choice for pressurizing the air behind a  
rack cabinet door is to mount a “squirrel  
cage” blower inside the rack (Option 1  
in Figure 1.2). At the bottom of the rack,  
mount the blower so it blows outside air  
into the space between the door and in  
front of the amplifiers, pressurizing the  
“chimney” behind the door. This blower should not blow air into or take air out  
of the space behind the amplifiers. For racks without a door, you can evacu-  
ate the rack by mounting the blower at the top of the rack so that air inside the  
cabinet is drawn out the back (Option 2 in Figure 1.2).  
If the air supply is unusually dusty, you might want to pre-filter it using com-  
mercial furnace filters to prevent rapid loading of the unit’s own air filter.  
1.1.2 Convection-Only Models  
When racking convection-cooled amplifiers, it is best to leave one rack-space  
between amps because this type of amplifier needs space to radiate the heat.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
7
1.2 System Wiring  
The information in this section covers making input and output wiring connec-  
tions, as well as troubleshooting problems relating to system wiring.  
1.2.1 Input Wiring  
Input Connector Wiring  
Refer to the following diagrams for input cable wiring for commonly-used con-  
nector types.  
Note: These diagrams follow the AES wiring convention of Pin 2 = hot for XLR  
connectors.  
Balanced, Grounded Source  
Balanced, Floating Source  
For use with components equipped with three-wire For use with components equipped with two-wire  
grounded AC line cord or other ground connection.  
AC line cord or battery power.  
Note: If two or more channels with the same  
input ground reference are driven from the  
same floating source, connect only one shield  
to the source chassis  
Amplifier Application Guide  
 
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Chapter 1: Crown Amplifiers In-Depth  
Unbalanced, Grounded Source,  
Twin-Lead Shielded Cable  
Unbalanced, Floating Source,  
Twin-Lead Shielded Cable  
For use with components equipped with three-wire For use with components equipped with two-wire  
grounded AC line cord or other ground connection.  
AC line cord or battery power.  
Unbalanced, Grounded Source, Single-  
Conductor Coax or Twisted-Pair Cable  
Unbalanced, Floating Source, Single-  
Conductor Coax or Twisted-Pair Cable  
For use with components equipped with three-wire For use with components equipped with two-wire  
grounded AC line cord or other ground connection.  
AC line cord or battery power.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
9
1.2.2 Solving Input  
Input Wiring Tips  
Problems  
Infrasonic (Subaudible)  
Frequencies  
1. For all input connectivity, use  
shielded wire only. Cables with a foil  
wrap shield or a high-density braid  
are superior. Cables with a stranded  
spiral shield, although very flexible,  
will break down over time and cause  
noise problems.  
to one another. If you must use a  
common path for all cables, use  
a star-quad cable for the low-level  
signals.  
Sometimes large infrasonic (sub-  
audible) frequencies are present in  
the input signal. These can damage  
loudspeakers by overloading or  
overheating them. To attenuate such  
frequencies, place a capacitor in  
series with the input signal line. The  
graph in Figure 1.3 shows some  
capacitor values and how they affect  
the frequency response. Use only  
low-leakage paper, mylar or tantalum  
4. Before changing input connec-  
tors or wiring, turn the amplifier level  
controls all the way down (counter-  
clockwise).  
2. Try to avoid using unbalanced  
lines with professional equipment. If  
you have no choice, keep the cables  
as short as possible (see “Balanced  
vs. Unbalanced” on the next page).  
5. Before changing output connec-  
tions, turn the amplifier level down  
and the AC power off to minimize the  
chance of short-circuiting the output.  
3. To minimize hum and crosstalk,  
avoid running low-level input cables,  
high-level output wires and AC power  
feeds in the same path. Try to run  
differing signal-cable paths at 90°  
capacitors.  
Radio Frequencies (RF)  
Another problem to avoid is the  
presence of large levels of radio  
frequencies or RF in the input signal.  
Although high RF levels may not  
pose a threat to the amplifier, they  
can burn out tweeters or other loads  
that are sensitive to high frequen-  
cies. Extremely high RF levels can  
also cause your amplifier to prema-  
turely activate its protection circuitry,  
resulting in inefficient operation. RF  
can be introduced into the signal  
chain from many sources such as  
Figure 1.3  
Subsonic Filter Capaci-  
tor Values  
local radio stations, tape recorder bias and digital signal processors (DSP). To prevent high  
levels of input RF, install an appropriate low-pass filter in series with the input signal.  
Some examples of unbalanced wiring for low-pass filters are shown in Figure 1.4.  
For balanced input wiring use one of the examples in Figure 1.5. Filters A, B and C correspond  
to the unbalanced filters above. Filter D also incorporates the infrasonic filter described previ-  
ously.  
Hum and Buzz  
If you have noticeable hum or buzz  
in your system, you may want to  
check your cable connections to  
Figure 1.4  
Unbalanced RFI Filters  
see if the unwanted noise is being  
introduced via a ground loop. To  
determine the proper wiring, first  
check whether the output from  
your source is unbalanced or bal-  
anced (if you don’t know, refer to  
the unit’s back panel or Operation  
Manual). Next, determine if the  
source’s power cable is floating  
(ungrounded, 2-prong) or grounded (3-prong). Finally, if the source in unbalanced, check the  
type of wiring: twin-lead or single coax. Once you have determined the wiring scheme and  
cable type, refer to the applicable wiring diagram in Section 1.2.1.  
Amplifier Application Guide  
 
10  
Chapter 1: Crown Amplifiers In-Depth  
Balanced vs. Unbalanced  
A balanced audio circuit will have both  
positive (+) and negative (–) legs of  
the circuit that are isolated from the  
ground circuit. These balanced legs  
exhibit identical impedance character-  
istics with respect to ground, and may  
also carry the audio signal at the same  
level, but with opposite polarities. This  
results in a line that offers excellent  
rejection of unwanted noise.  
On the other hand, an unbalanced  
circuit usually holds one leg at ground  
potential, while the second leg is “hot.”  
Unbalanced line is less expensive, but  
is much more susceptible to noise, and  
is not normally used in professional  
applications. For the cleanest signal,  
with less hum and buzz, a balanced  
line is always recommended. It is espe-  
cially helpful if you have a long cable  
run (over 10 feet (3 m)), since noise is  
easily introduced into long, unbalanced  
lines.  
Figure 1.5  
Balanced RFI Filters  
1.3 Output Wiring  
1.3.1 Output Connector Wiring  
5-Way Binding Post  
If the amplifier is set for Stereo  
(Dual), connect the positive (+)  
and negative (–) leads of each  
loudspeaker to the appropri-  
ate Channel 1 and Channel 2  
output connectors as shown in  
Figure 1.6.  
Figure 1.6  
5-Way Binding Post  
Wiring for Stereo  
If the amplifier is set for Bridge-Mono (if equipped), con-  
nect a mono load across the red binding posts of each  
channel as shown in Figure 1.7. Do NOT use the black  
binding posts when the amp is set for Bridge Output.  
Figure 1.7  
5-Way Binding Post  
Wiring for Bridge-Mono  
Notice that the Channel 1 red binding post is positive  
(+) and the Channel 2 red binding post is negative (–).  
If amp is set for Parallel-Mono (if equipped), connect  
a 14-gauge or larger jumper between the Channel 1  
and Channel 2 Positive terminals, then connect a mono  
load to the Channel 1 binding posts as shown in Figure  
1.8. Do NOT use the Channel 2 binding posts when the  
amp is set for Parallel Output. Caution: Never short or  
parallel the output channels of an amplifier to itself  
or to any other amplifier.  
Figure 1.8  
5-Way Binding Post  
Wiring for Parallel-  
Mono  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
11  
Barrier Block  
If the amplifier is set for Stereo (Dual), connect the positive (+) and negative (–) leads  
of each loudspeaker to the appropriate Channel 1 and Channel 2 output connectors  
as shown in Figure 1.9.  
Figure 1.9  
Barrier Block Wiring for  
Stereo  
If the amplifier is set for  
Bridge-Mono (if equipped),  
connect a mono load across  
the positive terminals of each  
channel as shown in Figure  
1.10. Do NOT use the nega-  
tive terminals when the amp  
is set for Bridge Output.  
Figure 1.10  
Barrier Block Wiring for  
Bridge-Mono  
If the amplifier is set for Parallel-Mono (if  
equipped), connect 14-guage or larger  
jumper between the Channel 1 and Channel  
2 Positive terminals, then connect a mono  
load to the Channel 1 positive and negative  
terminals as shown in Figure 1.11. Do NOT  
use the Channel 2 terminals when the amp  
is set for Parallel Output. Caution: Never  
short or parallel the output channels of an  
amplifier to itself or to any other amplifier.  
Figure 1.11  
Barrier Block Wiring for  
Parallel-Mono  
Neutrik® Speakon®  
To assemble the Neutrik Speakon NL4FC connector, complete  
the following steps:  
Output Wiring Tips  
1. To prevent possible short circuits,  
wrap or otherwise insulate exposed  
loudspeaker cable or cable connectors.  
1. Slide the bushing (E) and chuck (D) onto the end of the cable  
as shown in Figure 1.12.  
Note:Your NL4FC connector kit should contain both a black  
and a white chuck. Use the white chuck for cable with a diam-  
eter of 0.25 to 0.5 inch (6.35 to 12.7 mm). Use the black chuck  
for cable with a diameter of 0.375 to 0.625 inch (9.525 to  
15.875 mm).  
2. Do not use connectors that might  
accidentally tie conductors together  
when making or breaking the connec-  
tion (for example, a standard, 1/4-inch  
stereo phone plug).  
2. Strip approximately 3/4-inch (20-mm) of casing from the cable  
end. Strip approximately 3/8-inch (8-mm) from the end of each  
of the conductors down to bare wire (C).  
3. Never use connectors that could  
be plugged into AC power sockets.  
Accidental AC input will be an electri-  
fying experience for your equipment.  
But you will find out real quick if your  
speakers are any good at 60 Hz!  
3a.Insert each wire into the top of appropriate slot of the connec-  
tor insert (B) as shown in Figure 1.13. Use a (1.5-mm) allen  
wrench or flat blade screwdriver to tighten the side connecting  
screws.  
4. Avoid using connectors with low cur-  
rent-carrying capacity, such as XLRs.  
5. Do not use connectors that have  
any tendency to short.  
Amplifier Application Guide  
 
12  
Chapter 1: Crown Amplifiers In-Depth  
3b.If the Mode switch is  
in the “Stereo” posi-  
Figure 1.12  
Order of Assembly for  
the Neutrik Speakon  
NL4FC Connector  
tion (for stereo con-  
figuration), connect  
the positive (+) and  
negative (–) leads  
of each wire to the  
appropriate Chan-  
nel 1 and Channel  
2 connectors as  
shown in Figure  
1.14.You may use all 4 poles of the Channel 1 output  
connector to feed both speakers, if you wish.  
Figure 1.13  
Wiring for the Neutrik  
Speakon NL4FC  
Connector  
3c.If the Mode switch is in the “Bridge” position (for  
mono configuration), connect the load across the  
positive (+) terminals of the connector as shown  
in Figure 1.15. For Bridge-Mono Mode, non-invert-  
ing output, Ch1+ is the positive (+) and Ch2+ is the  
negative (–).  
3d. Never short or parallel the output channels of  
an amplifier to itself or any other amplifier.  
4. Slide the connector insert (B) into the connector  
hous-  
ing (A),  
making  
sure that  
Figure 1.14  
Stereo Output Wiring  
the large  
notch on  
the outer  
edge of the  
insert lines  
up with the  
large groove on the inside of the con-  
nector housing. The insert should slide  
easily through the housing and out the  
other side until it extends approximately  
3/4-inch (19-mm) from the end of the  
housing, as shown in Figure 1.16.  
Figure 1.15  
Bridge-Mono Output  
Wiring  
5. Slide the chuck (D) along the cable and  
insert into the housing, making sure  
that the large notch on the outer edge  
of the chuck lines up  
Figure 1.16  
with the large groove  
Connector Assembly:  
Insert into Connector  
Housing  
on the inside of the  
connector housing.  
The chuck should  
slide easily into the insert/hous-  
ing combination until only  
approximately 3/8-inch (9.5-mm)  
of the chuck end extends from  
the back end of the connector  
as shown in Figure 1.17.  
Figure 1.17  
Connector Assembly:  
Chuck into Connector  
Housing  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
13  
6. Slide the bushing along the cable  
and screw onto the end of the  
connector combination as shown  
in Figure 1.18. Note that the  
Figure 1.18  
Connector Assembly:  
Bushing onto Connector  
Housing Assembly  
bushing features a special lock-  
ing construction which will prevent  
disassembly of the NL4FC con-  
nector once this cap is tightened  
into place. Before tightening, you  
may want to test the connector in  
a live system to make sure it has  
been assembled properly.  
Figure 1.19  
Connecting the  
Speakon plug to the  
mating connector  
To connect the Speakon plug into the mating connector on the speaker, line  
up the notches between the insert and the mating connector, then insert the  
plug and turn one quarter-turn clockwise as shown in Figure 1.19. The thumb-  
lock on the housing will snap into the locked position when the connector is  
properly seated.  
1.3.2 Amplifier Load Impedance  
A major consideration when matching amplifiers with speakers is the resulting  
impedance presented to the amplifier when speakers are connected to the  
output. The impedance of the load, in part, determines how much power the  
amplifier will produce. Also, too low of impedance can cause the amplifier to  
overheat.  
Figure 1.20  
Series Speaker  
Impedances  
Impedance is much like resis-  
tance, except impedance  
changes with frequency. Imped-  
ance and resistance are both  
measured in ohms. To under-  
stand the effect of impedance  
in an electrical circuit, consider  
the following analogy: a wire is  
much like a water pipe. Elec-  
trical current is like the water  
flowing through the pipe. Imped-  
ance’s role is that of the valve.  
The valve resists or impedes  
(hence the terms) the flow of  
water through the pipe. If the  
valve is opened (less imped-  
ance), water flows freely. As  
the valve is turned toward the  
closed position (more imped-  
ance), the flow of water slows.  
As the amplifier drives lower  
impedances, it produces more  
current, thus more power.  
Figure 1.21  
Parallel Speaker  
Impedances  
Amplifier Application Guide  
 
14  
Chapter 1: Crown Amplifiers In-Depth  
Each speaker has an impedance  
rating, typically 4 or 8 ohms. Connect-  
ing one 8-ohm speaker to an amplifier  
channel presents an 8-ohm impedance  
to the channel.  
Parallel Impedances  
Figure 1.22  
Parallel Impedance  
Chart  
4 Ohm Speakers  
4 Ohm  
8 Ohm Speakers  
8 Ohm  
1 Speaker  
2 Speakers  
3 Speakers  
4 Speakers  
2 Ohm  
4 Ohm  
If two or more speakers are wired to  
the same channel, the net impedance  
presented to the channel will be either  
1.3 Ohm  
1 Ohm  
2.7 Ohm  
2 Ohm  
more or less than one of the speakers alone, depending on whether they  
were wired in series or in paral-  
lel (see Figures 1.20 and 1.21).  
Figure 1.23  
When speakers are wired in  
series, the net impedance pre-  
sented to the amp is the sum  
of the individual impedances.  
When wired in parallel, the net  
impedance becomes less than  
the impedance of one of the  
speakers, as calculated with the  
following formula:  
Wire Size Nomograph.  
You can use the table in Figure  
1.22 to find the net impedance  
for many common speaker  
combinations.  
Note: for best results, do  
not wire speakers of differ-  
ing impedances (one 4 ohm  
and one 8 ohm for example)  
together.  
If two 8-ohm speakers are wired  
in series, they form one 16-ohm  
load for the amplifier, since  
impedances add when speak-  
ers are wired in series. If, on the  
other hand, the same 8-ohm  
speakers are wired in paral-  
lel, they form one 4-ohm load  
for the amplifier. The 4-ohm  
load will cause the amplifier to  
produce much more power than  
the 16-ohm load, and much  
more waste heat as well.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
15  
1.3.3 Determining Appropriate Speaker Wire Gauge  
You should choose loudspeaker cables with sufficient gauge (thickness)  
for the length being used. The resistance introduced by inadequate loud-  
speaker cables will reduce both the output power and the motion control of  
the loudspeakers. The latter problem occurs because the damping factor  
decreases as the cable resistance increases. This is very important because  
the amplifier’s excellent damping factor can easily be negated by insufficient  
loudspeaker cables.  
Use the nomograph in Figure 1.23 and the procedure that follows to find the  
recommended wire gauge (AWG or American Wire Gauge) for your system.  
1. Note the load impedance of the loudspeakers connected to each channel  
of the amplifier. Mark this value on the “Load Impedance” (A) line of the  
nomograph.  
2. Select an acceptable damping factor and mark it on the “Damping Factor”  
(B) line. Higher damping factors yield greater motion control over the  
loudspeakers, and therefore lower distortion. A common damping factor for  
commercial applications is between 50 and 100. Higher damping factors  
may be desirable for live sound, but long cable lengths often limit the high-  
est damping factor that can be achieved practically. In recording studios  
and home hi-fi, a damping factor of 500 or more is very desirable.  
3. Draw a line through the two points with a pencil, and continue until it inter-  
sects the “Source Resistance” (C) line.  
4. On the “2-Cond. Cable” (D) line, mark the required length of the cable run.  
5. Draw a pencil line from the mark on the “Source Resistance” line through  
the mark on the “2-Cond. Cable” line, and on to intersect the “Copper Wire”  
(E) line.  
6. The required wire gauge for the selected wire length and damping factor is  
the value on the “Copper Wire” line. Note: Wire size increases as the AWG  
gets smaller.  
7. If the size of the cable exceeds what you want to use, (1) find a way to use  
shorter cables, (2) settle for a lower damping factor, or (3) use more than  
one cable for each line. Options 1 and 2 will require the substitution of new  
values for cable length or damping factor in the nomograph. For option  
3, estimate the effective wire gauge by subtracting 3 from the apparent  
wire gauge every time the number of conductors of equal  
gauge is doubled. So, if #10 wire is too large, two #13  
wires can be substituted, or four #16 wires can be used for  
the same effect.  
PIPs for Speaker Protection  
Depending on the application, you may  
want to use a PIP™ module to protect  
your loudspeakers (for PIP-compatible  
amps only). When properly configured, all  
PIP modules with signal-driven compres-  
sion can provide loudspeaker protection.  
For more information on available PIP  
modules with signal-driven compression,  
contact your Crown dealer or check the  
current selection of PIP modules at www.  
1.3.4 Loudspeaker Protection  
Crown amplifiers generate enormous power. If your loud-  
speakers don’t have built-in protection from excessive  
power, it’s a good idea to protect them. Loudspeakers are  
subject to thermal damage from sustained overpowering  
and mechanical damage from large transient voltages.  
Special fuses can be used to protect your loudspeakers in  
both cases.  
Amplifier Application Guide  
 
16  
Chapter 1: Crown Amplifiers In-Depth  
Two different types of fuses are  
required for thermal protection  
and voltage protection. Slow-blow  
fuses are usually selected to  
Figure 1.24  
Loudspeaker Fuse  
Nomograph  
protect loudspeakers from thermal  
damage because they are similar  
to loudspeakers in the way they  
respond to thermal conditions  
over time. In contrast, high-speed  
instrument fuses like the Littlefuse  
361000 series are used to protect  
loudspeakers from large transient  
voltages. The nomograph in Figure  
1.24 can be used to select the  
properly rated fuse for either type  
of loudspeaker protection.  
There are basically two  
approaches that can be taken  
when installing fuses for loud-  
speaker protection. A common  
approach is to put a single fuse  
in series with the output of each  
channel. This makes installa-  
tion convenient because there is only one fuse protecting the loads on each  
output. The main disadvantage of this approach becomes obvious if the fuse  
blows because none of the loads will receive any power.  
A better approach is to fuse each driver independently. This allows you to  
apply the most appropriate protection for the type of driver being used. In  
general, low-frequency drivers (woofers) are most susceptible to thermal  
damage and high-frequency drivers (tweeters) are usually damaged by large  
transient voltages. This means that your loudspeakers will tend to have better  
protection when the woofers are protected by slow-blow fuses and high-fre-  
quency drivers are protected by high-speed instrument fuses.  
1.3.5 Solving Output  
Problems  
High-Frequency Oscillations  
Sometimes high-frequency oscillations occur which can cause your amplifier  
to prematurely activate its protection circuitry and result in inefficient opera-  
tion. The effects of this problem are similar to the effects of the RF problem  
described in Section 1.2.2. To prevent high-frequency oscillations:  
1. Lace together the loudspeaker conductors for each channel; do not lace  
together the conductors from different channels. This minimizes the  
chance that cables will act like antennas and transmit or receive high fre-  
quencies that can cause oscillation.  
2. Avoid using shielded loudspeaker cable.  
3. Avoid long cable runs where the loudspeaker cables from different ampli-  
fiers share a common cable tray or cable jacket.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
17  
4. Never connect the amplifier’s  
input and output grounds together.  
Figure 1.25  
Inductive Load (Trans-  
former) Network  
5. Never tie the outputs of multiple  
amplifiers together.  
6. Keep loudspeaker cables well  
separated from input cables.  
7. Install a low-pass filter on each  
input line (similar to the RF filters described in Section 1.2.2).  
8. Install input wiring according to the instructions in your amplifier’s Opera-  
tion Manual.  
Sub-Sonic Currents  
Another problem to avoid is the  
presence of large sub-sonic currents  
when primarily inductive loads are  
used. Examples of inductive loads  
are 70-volt transformers and electro-  
static loudspeakers.  
Inductive loads can appear as a  
short circuit at low frequencies. This  
can cause the amplifier to pro-  
duce large low-frequency currents  
and activate its protection circuitry.  
Always take the precaution of install-  
ing a high-pass filter in series with  
the amplifier’s input when inductive  
loads are used. A 3-pole, 18-dB-  
per-octave filter with a –3 dB fre-  
quency of 50 Hz is recommended  
(depending on the application, an  
even higher –3 dB frequency may be  
desirable).  
Another way to prevent the amplifier  
from prematurely activating its protection systems and to protect inductive  
loads from large low-frequency currents is to connect a 590 to 708 µF nono-  
larized capacitor and 4-ohm, 20-watt resistor in series with the amplifier’s  
output and the positive (+) lead of the transformer. The circuit shown in Figure  
1.25 uses components that are available from most electronic supply stores.  
Figure 1.26  
Typical Distributed  
Speaker System  
1.3.6 Distributed Speaker Systems  
Multiple-speaker systems for paging and background music systems are  
common in such facilities as schools, restaurants, industrial facilities offices  
and retail. In these systems, many speakers are distributed throughout the  
facility, often across long distances, making them difficult and expensive to  
implement with traditional, direct low-impedance amplifiers. A less expensive  
and more reliable method is the distributed speaker system.  
A distributed speaker system consists of an amplifier or amplifier channel  
driving one or more speakers with transformers connected to a pair of wires  
called a “home run.The transformers step the line voltage down to a lower  
Amplifier Application Guide  
 
18  
Chapter 1: Crown Amplifiers In-Depth  
level to drive the speaker, and are connected across the  
wires (see Figure 1.26). The combination of transformer  
and speaker line presents a much higher impedance to the  
amplifier than would the speaker itself, making it possible to  
add many speakers to a single home run.  
Using Low-Impedance  
You can use amps without constant-volt-  
age settings on distributed speaker sys-  
tems if the power output is high enough.  
For example, an amplifier rated for 78  
watts output into 8 ohms will directly drive  
a 25-volt line. To calculate the necessary  
power for driving a specific voltage line  
use the following formula:  
In distributed speaker systems, as the ratio of voltage to  
current become greater, less power is lost on the home run.  
This makes it possible to use much smaller gauge wire for  
home runs than would otherwise be possible.  
What is Constant Voltage?  
“Constant-voltage” amplifiers do not, in fact, supply a con-  
stant output voltage. The audio is represented with varying  
voltage just as with a low-impedance amplifier. The term  
“constant-voltage” was arrived at for two reasons. First, con-  
stant-voltage amplifiers produce their maximum power when  
the output voltage reaches the specified value. For example,  
an amplifier rated at 200 watts, when set to 70V output, will  
produce 200 watts when the output voltage reaches 70V.  
Second, the output voltage of an amplifier driving a con-  
stant-voltage (distributed) speaker run remains constant  
across a wide range of impedances.  
where P equals the necessary power  
output,  
V equals the voltage of the distributed  
speaker system, and R equals the imped-  
ance of the amplifier for the power specifi-  
Transformer Saturation  
It’s important to know that transformers can easily become “saturated” at low-frequencies. Transformer saturation  
occurs when the magnetic field created by the signal content becomes too much for the core of the transformer to  
handle. This condition can be dangerous to the amplifier, and can also cause distortion.  
An effective way to prevent step-down transformer saturation is to filter the very low-frequency content from the  
audio.Your amplifier may provide high-pass filters for this purpose (see your Operation Manual). If not, see Sec-  
tion 1.2.2 for filter suggestions.  
1.4 Multi-way Systems  
(with Expansion Modules)  
This section shows how multi-way systems can be effectively designed using optional expansion modules that  
feature active crossover networks. Example systems are shown for single and multiple amp two-way systems and  
three-way systems.  
The range of frequencies present in full-range music is wider than most any single speaker component can accu-  
rately reproduce. Because of this, most professional speaker systems employ two or more speaker components  
to do the job. Crossover networks (or crossovers) are electrical circuits that divide an incoming signal into two  
or more separate frequency bands. The separate bands are then routed to speakers designed to reproduce the  
range of frequencies they are being fed.  
1.4.1 Active vs. Passive Crossover Networks  
There are two types of crossovers: active and passive. Passive crossover networks are located in the signal chain  
between the amplifier and speakers. The networks built into speaker cabinets are typically passive. The primary  
advantage to passive crossovers is that they use fewer amplified channels. The primary disadvantage is that they  
work with amplified or high-voltage signals because of being located after the amplifier in the signal chain,  
causing them to waste much of the power before it gets to the speakers. They also have lower dynamic  
range.  
Active crossovers are typically located before the amplifier in the signal chain. They work with lower “line-level”  
signals, meaning they waste much less power.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
19  
Figure 1.27  
Typical Single-Amp,  
Stereo, Two-Way  
Hookup  
Figure 1.28  
Typical Two-Amp,  
Bridge-Mono, Two-Way  
Hookup  
Amplifier Application Guide  
 
20  
Chapter 1: Crown Amplifiers In-Depth  
Figure 1.29  
Typical Three-Amp,  
Bridge-Mono,  
Three-Way Hookup  
When you use an active crossover to split the power drive to the loudspeaker  
components, you gain a wide range of advantages, including:  
1. Increased gain because the insertion loss of passive crossover networks is  
eliminated.  
2. Consistent power bandwidth: power bandwidth is changed in multi-way pas-  
sive systems if transducers change impedance or vaporize (blow up).  
3. Levels can be matched  
more accurately to the  
components.  
Figure 1.30  
Fault Status External  
Circuit Design  
4. Improved dynamic  
range.  
Active crossovers for  
Crown amps are available  
in both PIP and SST mod-  
ules (see your Operation  
Manual for details about  
available options for your amplifier).  
Figures 1.27 through 1.29 illustrate typical systems using active crossover  
modules.  
Amplifier Application Guide  
 
Chapter 1: Crown Amplifiers In-Depth  
21  
1.5 Fault Monitoring  
Figure 1.31  
RJ Jack Wiring and  
Pin Assignments  
The Fault (RJ-11) jack, which looks  
like a telephone plug, is located  
on the back of your amplifier (if  
equipped). It gives you an easy way  
to remotely monitor the amplifier’s fault status. To set up a circuit that will  
cause an LED to light whenever a fault status occurs, you can simply use the  
suggested circuit shown in Figure 1.30.  
When using this circuit, the LED will glow whenever the amplifier is in one of  
four states: a channel’s heatsink has reached its temperature limit, the trans-  
former has reached its temperature limit, the amplifier has just been turned  
on and is in its turn-on-delay mode, or the amplifier is turned off.  
If you choose to design your own circuit to interface this signal to your system,  
note that this RJ jack is polarity sensitive. Pin 2 must be grounded, and Pin  
5 must be supplied with a positive voltage pull up (positive with respect to  
ground). Refer to Figure 1.31 for RJ jack pin assignments. Note: the mating  
connector for the RJ-11 jack contains 4 contact pins in a six-slot case, as  
shown in Figure 1.31. The maximum signal that can be exposed to the fault  
jack is 35 VDC and 10 mA. Best results are obtained with 10 mA LEDs.  
1.6 Setting  
Figure 1.32  
Optimal System  
Headrom.  
Available  
Headroom  
System Gain  
Amplifier  
Gain  
Headroom  
Structure  
Potential  
To get the best performance  
from your sound system, you  
should carefully set up your  
system’s gain structure. Gain  
structure is a term that refers  
Amplifier  
to the way the various levels  
are set at each stage of your  
sound system. Good gain  
structure lets you get your  
intended signal out with the  
Outboard  
Processing  
most available headroom, and  
the least amount of noise.  
Mixer  
Output  
Mixer  
Input  
This section provides a basic  
procedure to use to set up you  
system’s gain structure, designed to get you up and running as quickly as  
possible. We could go into much more detail on this subject, but that would  
be beyond the scope of this manual. If you have questions about system gain  
structure, refer to the Appendix for a list of recommended publications for  
further reading.  
Amplifier Application Guide  
 
22  
Chapter 1: Crown Amplifiers In-Depth  
1.6.1 System Levels  
When setting system gain, start at the front of the system and work your way toward the  
amplifier. A system with the lowest noise floor and maximum overall gain will have most  
of its gain early in the signal chain.  
Start out by setting your mixer’s individual channels to 0 dB. The individual channels will  
vary somewhat from this in the course of setting the mix, but it is a good target position.  
Also, if your mixer has a +4/–10 dB switch on the output, set it to the +4 dB position.  
Next, if your mixer has input trim controls for the mic channels, set them for the highest  
possible gain (but short of clipping) by having someone speak or sing into the mic while  
monitoring the mixer’s metering.  
Set up your mix for the balance of signals as you want them, keeping the input faders  
somewhere around the 0 dB point. If necessary, turn down the trim on a channel if  
you’re not able to keep the fader near the 0 dB point.  
After the mix is set, adjust the master levels on the mixer to 0 dB. Any signal processing  
equipment should generally be set to 0 dB as well, with some exceptions (refer to each  
component’s documentation for details).  
1.6.2 Amplifier Level  
Before you can know how to set your amps level controls, you need to understand how  
they work. Amplifier level controls are typically not “gain” controls. They do not control  
the amount of gain the amplifier produces.You may be tempted to immediately turn your  
amps level control all the way up (after all, you do want all the Crown power you can get,  
don’t you?). While that approach could work sometimes, usually it will yield more noise  
and less overall system gain than would otherwise be possible.  
Power amplifiers are designed to produce a set amount of gain. The function of the level  
control knob typically is to adjust the signal level coming into the amplifier’s input stage.  
Where to set the level controls on the amp depends on the system and how much gain  
you have available prior to the amplifier. With the level controls turned down the ampli-  
fier can still reach full rated output power, it just takes more drive level from your mixer to  
achieve it.  
First, check to make sure your mixer or console is being operated at optimum signal-to  
-noise, without clipping the output. Then—with your amplifier’s input sensitivity set to  
the 26 dB position (if equipped)—turn up your amp’s level controls until you achieve the  
desired level (loudness). If you turn the level controls all the way up, and it’s still not loud  
enough, turn the amplifier level controls all the way down (counter-clockwise). Then,  
change the sensitivity switch to the 1.4V position (if equipped). This will increase the  
gain of the amplifier. Now carefully turn the amplifier level controls up (clockwise) to the  
desired level (loudness). If its still not loud enough, and your amplifier has a 0.775V sen-  
sitivity setting, turn the amplifier level controls all the way down (counter-clockwise), then  
change the sensitivity switch to the 0.775V position. Take care when you are adjusting  
the level controls at this input sensitivity setting. Increasing the input sensitivity of the  
amplifier may cause the input stage of the amp to overload, so be prepared to back  
down the output of the mixer by 1 or 2 dB if you notice the amplifier’s warning indicators  
beginning to flash.  
Note: depending upon your model of Crown amplifier, sensitivity settings are internal  
and NOT user-selectable. Internal sensitivity settings may only be adjusted by qualified  
service personnel. Refer to your amplifier’s Operation Manual for specifics about sensi-  
tivity settings on your amplifier.  
Amplifier Application Guide  
 
Chapter 2: Troubleshooting  
23  
Chapter  
Troubleshooting  
2
In This Chapter  
Troubleshooting Flowcharts  
his section provides flowcharts to assist you in troubleshooting problems  
Twith your amplifier. In some situations the problem may not be with the  
amplifier, but rather may be caused by a system condition.  
The flowcharts do not cover every possible scenario you may encounter.  
Figure 2.1 provides a key to help you interpret the flowcharts.  
Figure 2.1  
Flowchart Key  
Start and  
Finish Points  
Question  
Comment  
Action Step  
Amplifier Application Guide  
 
24  
Chapter 2: Troubleshooting  
2.1 No Power  
Figure 2.2  
No Power  
No Power  
Is amp plugged  
in to the AC  
source?  
Plug amp in to the  
AC source.  
No  
Yes  
Is the Power  
(Enable)  
switch on?  
Turn the Power  
(Enable) switch on.  
No  
Yes  
Is the Power  
(Enable)  
indicator lit?  
Is AC source  
supplying power  
to outlet?  
Restore AC power  
to outlet.  
No  
No  
Yes  
Yes  
Does amp have  
a fuse or circuit  
breaker?  
Circuit  
Breaker  
Reset circuit  
breaker.  
Is an  
Verify power to  
amp is turned on  
in IQ System.  
Fuse  
Did it trip  
again?  
Amp o.k. to  
operate.  
IQ System  
controlling  
amp?  
No  
Yes  
Is fuse  
internal or  
external?  
Yes  
Replace fuse  
with new fuse  
of identical  
rating.  
No  
Internal  
External  
Internal Fuses  
NOT  
user-replaceable.  
Refer amp to  
service center.  
Amplifier Application Guide  
 
Chapter 2: Troubleshooting  
25  
2.2 No Sound  
Figure 2.3  
No Sound  
No Sound  
Check AC Power to  
amp. See "No Power"  
flowchart.  
Is Power or  
Enable  
indicator on?  
No  
Yes  
Does amp have  
IQ PIP model  
installed?  
Are signal  
indicators  
blinking?  
Check settings on  
IQ PIP module.  
Check signal source  
for adequate output.  
Yes  
No  
No  
Yes  
Are the level  
controls  
turned up?  
Turn up level controls  
until you hear output.  
Are speakers'  
protection  
systems tripped,  
or speakers  
damaged?  
No  
Repair or reset  
speaker.  
Yes  
Yes  
No  
Connect Speakers  
to Amp.  
Are speakers  
connected?  
No  
Does amp have  
Fault, TLC or  
ODEP  
indicators?  
Yes  
Neither Fault,  
TLC or ODEP  
Is there a  
short-circuit on  
the speaker  
line?  
Fault or TLC  
ODEP  
Remove the  
short-circuit.  
Yes  
Is indicator  
off?  
Yes  
Is indicator  
on?  
No  
No  
Yes  
Amp overheated or in  
other standby condition.  
See "Amp Overheating"  
flowchart and/or refer to  
Operation Manual.  
No  
Refer amp to  
service center.  
Amplifier Application Guide  
 
26  
Chapter 2: Troubleshooting  
2.3 Bad Sound  
Figure 2.4  
Bad Sound  
Are ODEP  
indicators (if  
equipped) dim or  
off?  
Amp overheating.  
See "Amp  
Overheating"  
flowchart.  
Yes  
Bad Sound  
No  
Is source signal  
clean and  
undistorted?  
Check levels and/or  
indicators at source  
level for clipping.  
No  
Are the IOC or  
Clip indicators (if  
equipped)  
Check amp  
for clipping.  
Yes  
Possible Causes  
flashing or on?  
Yes  
No  
Amp not adequately  
cooled. See "Amp  
Overheating"  
System Gain  
Is there a  
Hum or Buzz  
sound?  
See "Hum and  
Buzz" in  
Section 1.2.2.  
Structure. See  
"Setting System  
Gain Structure in  
Section 1.6.  
Yes  
flowchart.  
Are input and  
output  
connections o.k.?  
No  
No  
Secure input and  
output connections.  
Yes  
Refer amp to  
service center.  
Figure 2.5  
Amp Overheating  
Amp  
Overheating  
2.4 Amp  
Overheating  
Are the filters  
(if equipped)  
clogged?  
Clean or replace  
Yes  
filters.  
No  
See "Rack Cooling" in  
Section 1.1, and info  
on amp cooling in  
Is the amp  
getting enough  
cool air?  
No  
Operation Manual.  
Yes  
Is the amp  
operating within  
its rated  
Lower impedances cause  
amps to dissipate more  
heat. See "Amplifier Load  
Impedance" in Section 1.3.2.  
Yes  
impedance?  
No  
Refer amp to  
service center.  
Amplifier Application Guide  
 
Chapter 3: Glossary of Terms  
27  
Chapter  
Glossary of Terms  
3
In This Chapter  
• Glossary of Terms  
his section provides a handy glossary of terms used in the discussion of profes-  
Tsional audio amplifiers. Some terms are unique to Crown amplifiers. Most of the  
terms provided do not directly relate to amplifiers, but as amplifiers are but one piece  
of a larger audio system, are often used when discussing amp usage.  
Band-Pass Filter  
Amperage  
In a crossover, a filter that passes a band or range of frequen-  
cies but sharply attenuates or rejects frequencies outside the  
band.  
A measure of electrical current flow, also called “amps” for  
short. It literally equates to the number of electrons in a  
conductor flowing past a certain point in a given amount of  
time. Ohms law defines current (I) as voltage (V) divided by  
resistance (R) with the following expression: I=V/R.  
Barrier Block/Barrier Strip  
A series of connections, usually screw terminals, arranged  
in a line to permanently connect multiple audio lines to such  
devices as recording equipment, mixers, or outboard gear.  
Also called terminal strip.  
Amplifier (Amp)  
A device that increases signal. Many types of amplifiers are  
used in audio systems. Amplifiers typically increase voltage,  
current, or both.  
BCA®  
BCA (Balanced Current Amplifier) is Crown’s patented PWM  
(Pulse-Width Modulation) amplifier output stage topology.  
Also referred to as “class-I,Crown’s BCA “switching” technol-  
ogy provides for high output, exceptional reliability and nearly  
twice the efficiency of typical amplifier designs. To learn more  
about BCA, download and read the BCA white paper at www.  
crownaudio.com.  
Amplifier Class  
Audio power amplifiers are classified primarily by the design  
of the output stage. Classification is based on the amount  
of time the output devices are made to operate during each  
cycle of swing. Amplifiers are also defined in terms of output  
bias current (the amount of current flowing in the output  
devices with no signal present). Common amplifier classes  
used in professional audio amplifiers include AB, AB+B, D, G  
and H.  
Binding Post (5-Way, Banana)  
A type of electrical terminal, a binding post is most commonly  
found as the output connector on a power amplifier, or as the  
connectors on a speaker cabinet. A binding post can accept  
banana plugs, spade lugs, bare wire and others. Generally,  
binding posts are color coded, with the black connection  
going to ground, and the red connecting to hot.  
Attenuation  
A decrease in the level of a signal is referred to as attenua-  
tion. In some cases this is unintentional, as in the attenuation  
caused by using wire for signal transmission. Attenuators  
(circuits which attenuate a signal) may also be used to lower  
the level of a signal in an audio system to prevent overload  
and distortion.  
Bridge-Mono  
An operating mode of an amplifier that allows a single input  
to feed two combined output channels in order to provide a  
single output with twice the voltage of an individual channel in  
Stereo or Dual mode.  
Balanced Line  
A cable with two conductors surrounded by a shield, in which  
each conductor is at equal impedance to ground. With respect  
to ground, the conductors are at equal potential but opposite  
polarity; the signal flows through both conductors.  
Amplifier Application Guide  
 
28  
Chapter 3: Glossary of Terms  
Bus  
rent is measured in Amperes (or Amps), abbreviated I. Ohms  
law defines current as voltage (V) divided by resistance (R)  
with the following expression: I=V/R.  
In audio terms, a Bus is a point in a circuit where many sig-  
nals are brought together. For example: Most electronic items  
have a Ground Bus where all of a device’s individual ground  
paths are tied together. In mixers, we have Mix Busses, where  
multiple channels’ signals are brought (or blended) together,  
and Aux Busses, where feeds from channels are brought  
together to be routed to an external processor or monitor  
send, etc. In general, the more busses a mixer has, the more  
flexible the routing capabilities of that mixer will be.  
Damping Factor  
Though technically more complex than this, damping factor  
is usually thought of as an indicator of how tight an amplifier  
will sound when powering bass speakers. A speaker’s driving  
motor is a coil of wire (called a voice coil) mounted within a  
magnetic field. As this coil of wire moves within the field a  
voltage will be induced in the voice coil. If resonant motions of  
the speaker are not sufficiently short-circuited by the ampli-  
fier, the speaker output can have an over accentuated or  
“boomy” bass sound.  
Capacitor  
An electronic component that stores an electric charge. It is  
formed of two conductive plates separated by an insulator  
called a dielectric. A capacitor passes AC but blocks DC.  
From a technical measurement stand point, damping factor  
is the ratio of the rated speaker impedance to the amplifier’s  
output impedance. Low output impedance is the consequence  
of the amplifier having substantial negative voltage feedback  
taken from its output terminals. Properly designed negative  
feed back not only corrects for output voltage errors induced  
by the speaker but also produces other benefits, including low  
distortion, low noise (hiss), and flat frequency response.  
Channel Separation  
Relates to crosstalk, or bleed of audio signals from one chan-  
nel to another. The amount of channel separation is inversely  
related to the item’s crosstalk spec; i.e. a low crosstalk spec  
indicates high channel separation.  
Circuit Breaker  
A resettable device intended to provide protection to electrical  
circuits. It opens when current flows though it that exceeds its  
current rating.  
DC Output Offset  
The presence of DC (Direct Current) at the output of the  
amplifier. Any more than approximately 10 millivolts (positive  
or negative) could be an indication of a problem within the  
amplifier.  
Clipping  
A specific type of distortion. If a signal is passed through an  
electronic device which cannot accommodate its maximum  
voltage or current requirements, the waveform of the signal  
is sometimes said to be clipped, because it looks on a scope  
like its peaks have been clipped off by a pair of scissors. A  
clipped waveform contains a great deal of harmonic distortion  
and often sounds very rough and harsh. Clipping is what typi-  
cally happens when an audio amplifier output is overloaded  
or its input over driven.  
Decibel  
A decibel, a tenth of a bel, is used as an expression of the  
ratio between signal levels.  
One decibel is commonly taken as the smallest volume  
change the human ear can reasonably detect. Doubling the  
POWER of an amplifier results in a 3 dB increase, which is  
a “noticeable” volume increase. Doubling the VOLUME of a  
sound is a 10 dB increase.  
A Clip Indicator on an amplifier indicates the presence of clip-  
ping distortion.  
dBV is decibels relative to 1 volt. dBu is decibels relative to  
0.775 volt. dBm is decibels relative to 1 milliwatt.  
Compressor  
A compressor is a device that reduces the dynamic range of  
an audio signal. First a threshold is established. When the  
audio signal is louder than this threshold, its gain is reduced.  
Distributed Speaker System (Constant Voltage System)  
A type of speaker system where transformers typically are  
used at the output of an amplifier and at each speaker in  
order to provide a constant voltage (most commonly 70V or  
Crossover Network (Crossover)  
An electronic network that divides an incoming signal into two 100V) that can be tapped by multiple speakers. These lines  
or more frequency bands.  
can be run great distances with less loss and can have many  
more speakers on them than typical high current speaker  
lines. These types of systems are generally employed in  
situations where an amplified signal must be distributed over  
vast areas without a need for very high sound level in any  
one area. This type of P.A. system is typically used in schools,  
churches, business offices, and other commercial facilities.  
Crossover Slope  
High- and low-pass filters used for speakers do not cut off fre-  
quencies like brick walls. The roll-off occurs over a number of  
octaves. Common filter slopes for speakers are 1st- through  
4th-order corresponding to 6 dB per octave to 24 dB per  
octave. For example, a 1st-order, 6 dB per octave high-pass  
filter at 100 Hz will pass 6 dB less energy at 50 Hz, and 12  
dB less energy at 25 Hz. Within the common 1st through 4th  
filters there is an endless variety of crossover types including  
Butterworth, Linkwitz-Riley, Bessel, Chebychev and others.  
Dynamic Range  
The dynamic range of a sound is the ratio of the strongest or  
loudest part, to the weakest or softest part; it is measured in  
dB. An orchestra may have a dynamic range of 90 dB, mean-  
ing the softest passages have 90 dB less energy than the  
loudest ones.  
Crosstalk  
Signal bleeding or leaking from one channel of a multi-chan-  
nel device to another.  
EMI  
EMI (Electro Magnetic Interference) refers to interference in  
audio equipment produced by the equipment or cabling pick-  
ing up stray electromagnetic fields. This interference usually  
Current  
Literally, the rate of electron flow in an electrical circuit. Cur-  
Amplifier Application Guide  
 
Chapter 3: Glossary of Terms  
29  
manifests itself as some type of hum, static, or buzz. Such  
electromagnetic fields are produced by fluorescent lights,  
power lines, computers, automobile ignition systems, televi-  
sion monitors, solid state lighting dimmers, AM and FM radio  
transmitters, and TV transmitters. Methods for controlling  
EMI include shielding of audio wiring and devices, ground-  
ing, elimination of ground loops, balancing of audio circuits,  
twisting of wires in balanced transmission lines, and isolation  
transformers among others. Completely eliminating EMI in  
a system ranges from easy to nearly impossible depending  
upon the equipment and the environment in question.  
plug, the ground connection on the plug is wired to the  
component’s chassis. This wire conducts electricity to power  
ground if the chassis becomes electrically “hot,preventing  
electrical shock.  
In audio, ground usually refers to either the electrical ground  
mentioned above, or to an audio shield. An audio shield is  
not always a ground and should never be used as a safety  
ground. That they are often at ground potential is a function  
of how they may be connected to other equipment. Many  
audio devices have the ability to disconnect their signal paths  
entirely from electrical ground as a way to prevent hum or  
ground loop problems.  
Equalization (EQ)  
The adjustment of frequency response to alter tonal balance  
or to attenuate unwanted frequencies.  
Verb - to “ground” something means connecting it electrically  
to ground.  
Fader  
Ground Lift  
Another name for variable attenuator, volume control, or  
potentiometer. A fader works like a standard potentiometer,  
only instead of rotating, it slides along a straight path. Faders  
are commonly found on mixers.  
Ground lift is a switch found on many pieces of audio equip-  
ment which disconnects audio signal ground from earth or  
chassis ground.  
Using ground lift switches is considered to be far safer than  
the “3-to-2 prong AC adapter” solution.  
Fault  
A term used to describe any condition that could cause an  
amplifier or amplifier channel to place itself in “standby” or  
offline mode for protection.  
Ground Loop  
A loop or circuit formed from ground leads.  
The loop formed when unbalanced components are con-  
nected together via two or more ground paths–typically the  
connecting-cable shield and the power ground. Ground loops  
cause hum and should be avoided.  
An indicator on some Crown amplifiers that blinks to show  
that the amplifier is in “Fault,or a standby or offline condition.  
Frequency  
In audio, the number of cycles per second of a sound wave  
of an audio signal, measured in hertz (Hz). A low frequency  
(for example 100 Hz) has a low pitch; a high frequency (for  
example 10,000 Hz) has a high pitch.  
Grounded Bridge™  
Grounded Bridge is the name of an amplifier output topology  
developed by Crown in the 1980’s, and used in many Crown  
amplifier models. The patented Grounded Bridge design  
consists of four quadrants and an ungrounded power supply.  
While two of the output quadrants operate much like a con-  
ventional (AB+B push-pull) linear amplifier, the other two work  
in a push-pull configuration to control ground reference for the  
Frequency Range/Frequency Response  
Frequency Range is the actual span of frequencies that a  
device can reproduce, for example from 5 Hz to 22 kHz.  
Frequency Response is the Frequency Range versus Ampli-  
tude. In other words, at 20 Hz, a certain input signal level may supply rails.  
produce 100 dB of output. At 1 kHz, that same input level may  
To learn more about Grounded Bridge, download and read  
produce 102 dB of output. At 10 kHz, 95 dB, and so on.  
Fuse  
Headroom  
A device intended to provide protection to electrical circuits.  
It burns open when current flows though it that exceeds its  
current rating.  
The difference between the normal operating level of a  
device, and the maximum level that device can pass without  
distortion. In general the more headroom the better.  
Gain  
Hertz  
How much an electronic circuit amplifies a signal is called  
its “gain.In most specs or references gain is expressed as  
a decibel value. Occasionally gain may be expressed as a  
straight numeric ratio (a voltage gain of 4 or a power gain of  
2).  
The inverse of the time required for one complete cycle of  
a wave. Thus, a 10 Hz sine wave takes 1/10 of a second to  
complete a full cycle. In practice, it is the frequency or number  
of wave cycles occurring per second. In the audio range this  
equates to what we perceive as pitch. Abbreviated Hz.  
Ground  
High-Pass Filter  
In electricity, a large conducting body, such as the earth or an  
electric circuit connected to the earth, used as a reference  
zero of electrical potential.  
A filter that passes frequencies above a certain frequency  
and attenuates frequencies below that same frequency. It can  
also be called a low-cut filter.  
A conducting object, such as a wire, that is connected to a  
position of zero potential for the purpose of “grounding” an  
electronic device.  
Hum  
An unwanted low-pitched tone (60 Hz and its harmonics)  
heard in the speakers. The sound of interference generated  
A power ground or safety ground is a connection to the power in audio circuits and cables by AC power wiring. Hum pickup  
company’s earth ground through the power outlet. In the  
power ground of an electronic component with a grounded  
is caused by such things as faulty grounding, poor shielding,  
and ground loops.  
Amplifier Application Guide  
 
30  
Chapter 3: Glossary of Terms  
I
I
Load/ Limit Indicator  
50 to 60 Hz).  
An indicator of some Crown amplifiers that shows current flow  
to the loudspeakers (“current load”) and the maximum cur-  
rent available from the amplifier (“current limit”). Typically, the  
indicator will glow one color to indicate that current is flowing  
to the loads connected to the amplifier output channel, and  
change to another color to show that the amplifier channel is  
delivering its maximum output current.  
Loudspeaker  
A transducer that converts electrical energy (the signal) into  
acoustical energy (sound waves).  
Loudspeaker Offset Integration  
A feature on some Crown amplifiers that helps reduce output  
clipping and off-center woofer cone movement caused by the  
presence of large infrasonic (subaudible) frequencies. The  
circuit adds a third order high-pass Butterworth filter with a –3  
dB frequency of 35 Hz.  
Impedance  
Impedance refers to the resistance of a circuit or device to AC  
(alternating current). Most modern electronic audio devices  
have extremely high input impedances so they can be driven  
by very low power outputs. Impedance is measured in ohms.  
The symbol Ω (omega) is often used to represent resistance.  
Low-Pass Filter  
A filter that passes frequencies below a certain frequency and  
attenuates frequencies above that same frequency. It can  
also be called a high-cut filter.  
Input  
Mic Level  
The connection going into an audio device. In a mixer or  
mixing-console, a connector for a microphone, line-level  
device, or other signal source.  
The level (or voltage) of signal generated by a microphone.  
Typically around 2 millivolts.  
Negative Feedback  
Intermodulation Distortion (IMD)  
If some of the output of an amplifier is made to be out of  
phase, and mixed back with the amp’s input signal, it will  
partially cancel the input, reducing the gain of the amplifier;  
this is called negative feedback. But, because it contains and  
therefore cancels any distortion introduced by the amplifier,  
negative feedback also has the effect of improving the linear-  
ity of the amplifier. Negative feedback can also lower output  
impedance, increasing damping factor, and can sometimes  
be made to flatten frequency response. The key to negative  
feedback amplifiers is careful design. Too much phase shift  
and the amp will be unstable, and too much feedback will  
cause Transient Intermodulation Distortion.  
Nonlinear distortion that occurs when different frequencies  
pass through an amplifier at the same time and interact to  
create combinations of tones unrelated to the original sounds.  
IMD specifications are usually expressed as a percentage of  
the amplifier’s output, and the lower the percentage the better.  
IOC®  
The IOC (Input Output Comparator) circuit compares the  
output signal of the amplifier with the input signal. If there is  
any difference other than gain, then it is considered distor-  
tion and the indicator comes on. The LED indicator will come  
on whenever there is distortion of 0.05% or more. This is a  
dynamic Proof of Performance of the amplifiers functionality.  
Anytime you experience distortion in your system you can  
view the IOC indicators. If they are not lit then you know that  
the amplifier is not at fault. If the IOC indicators are on, then  
the amplifier is in distortion.  
Noise  
Unwanted sound, such as hiss from electronics or tape. An  
audio signal with an irregular, non-periodic waveform.  
Noise Floor  
The noise floor of a device or system is the amount of noise  
generated by the device itself with no signal present, it is  
measured in decibels. All electronic devices will generate a  
certain amount of noise, even a piece of wire! Minimizing the  
noise floor leads to expanded dynamic range, and cleaner  
recordings or sound production.  
To learn more about IOC, download and read the IOC white  
Limiter  
A limiter is a dynamics processor very similar to a compres-  
sor. In fact, many compressors are capable of acting as limit-  
ers when set up properly. The primary difference is the ratio  
used in reducing gain. In a limiter, this ratio is set up to be as  
close to infinity:1 as possible (no matter how much the input  
signal changes, the output level should remain pretty much  
constant). The idea is that a limiter establishes a maximum  
gain setting, and prevents signals from getting any louder  
than that setting.  
ODEP®  
ODEP (Output Device Emulator Protection) is an analog  
computer simulation of the output device thermal imped-  
ance. In layman’s terms ODEP stores how much power the  
amplifier delivers to its load and its heatsink temperature. If  
the protection circuit determines that the output stage is being  
overstressed or cannot dissipate any further heat, then output  
stage drive is limited.  
Line Level  
Generally defined in the audio industry as +4 dBu (1.23 volts)  
for balanced “pro” gear, and .316 volts (–10 dBV) for unbal-  
anced “semi-pro” gear. “ It is best to match the levels of the  
gear you are using so that –10 dBV equipment isn’t directly  
feeding +4 dBu equipment, and vice versa. If you use gear of  
both levels, there are various level matching devices on the  
market to properly interface the items.  
To learn more about ODEP, download and read the ODEP  
Output  
A connector in an audio device from which the signal comes  
and then feeds successive devices.  
Overload  
Linear Power Supply  
The distortion that occurs when an applied signal exceeds a  
A power supply that converts AC mains power for use by the  
amplifier by means of a conventional transformer operating at  
the same frequency as that of the AC mains supply (usually  
system’s maximum input level.  
Parallel-Mono  
As implemented in Crown amplifiers, an operating mode of  
Amplifier Application Guide  
 
Chapter 3: Glossary of Terms  
31  
the amplifier that allows a single input to feed two combined  
output channels in order to provide a single output with twice  
the current of an individual channel in Stereo or Dual mode.  
power level fed into it to a level sufficient to drive a loud-  
speaker.  
Radio Frequency Interference (RFI)  
Radio-frequency electromagnetic waves induced in audio  
cables or equipment, causing various noises in the audio  
signal.  
Removable Terminal Block (Buchanan®, Phoenix)  
A series of screw terminal connections arranged in a line on a  
removable connector. Often found in three-terminal and four-  
terminal versions in audio applications. Often referred to by  
their brand name, such as “Buchanan®” and “Phoenix.”  
Peak  
On a graph of a sound wave or signal, the highest point in the  
waveform. The point of greatest voltage or sound pressure in  
a cycle.  
Phase Response  
The measure of displacement of a time-varying waveform  
between an amplifier’s input and output. Expressed in  
degrees.  
Phone Plug  
Resistance  
A cylindrical plug, usually 1/4-inch (6.35-mm) in diameter. An  
unbalanced phone plug typically has a tip for the hot signal  
and a sleeve for the shield or ground. A balanced phone  
plug typically has a tip for the hot signal, a ring for the return  
signal, and a sleeve for the shield or ground.  
The opposition of a circuit to a flow of direct current. Resis-  
tance is measured in ohms. The symbol Ω (omega) is often  
used to represent resistance. Ohms law defines resistance as  
voltage (V) divided by current (I) with the following expression:  
R=V/I.  
Phono Plug  
Resistor  
A coaxial plug with a central pin for the hot signal and a ring  
of pressure-fit tabs for the shield or ground. Phono plugs are  
used for unbalanced signals only. Also called an RCA plug or  
pin jack.  
An electronic component that opposes current flow.  
Sensitivity  
In audio terms, sensitivity is the minimum amount of input  
signal required to drive a device to its rated output level.  
Normally, this specification is associated with amplifiers and  
microphones, but FM tuners, phono cartridges, and most  
other types of gear have a sensitivity rating as well.  
PIP™  
PIP stands for Programmable Input Processor. These are  
optional modules that can be plugged into any PIP-compat-  
ible amplifier. There are a variety of PIP modules with varying  
functions. Since first introducing PIP-compatible amplifiers  
and PIP modules, Crown has updated the PIP standard. This  
affects which PIP-compatible amplifiers can host certain PIP  
modules. Following are descriptions of the two PIP standards.  
Crown’s original PIP module was designed with a 22-pin edge  
connector, which mated with a slide-in card rail on PIP-com-  
patible amplifiers.  
Shield  
In electronic terms, a shield is a conductive enclosure,  
protecting its contents from magnetic and electrostatic fields.  
Since audio conductors and circuits tend to be extremely  
sensitive to such fields, shields are very important. In cabling,  
shields often consist of braided copper strands wrapped  
around the signal conductors. The amount of coverage the  
shield provides is directly related to the noise and hum per-  
formance of the cable. Some cables offer a shield consisting  
of a thin wrap of metallic sheeting, which can offer complete  
coverage of the encased signal conductors.  
PIP2™  
The PIP2 standard, announced in 1998, upgraded the PIP  
feature set and requires both 18- and 20-pin ribbon cables  
which mate with a PIP2-compatible amplifier using standard  
ribbon connectors.  
Signal-To-Noise Ratio (S/N)  
The ratio in decibels between signal voltage and noise volt-  
age. An audio component with a high S/N has little back-  
ground noise accompanying the signal; a component with a  
low S/N is noisy.  
Polarity  
In electronics, the relationship between two points that have  
opposite electric potentials (one is positive, the other nega-  
tive) irrespective of time. This is not the same as being 180  
degrees out of phase (although the results can be similar).  
Phase implies a relationship with time, polarity does not.  
Sine Wave  
A wave following the equation y = sin x, where x is degrees  
and y is voltage or sound pressure level. The waveform of  
a single frequency. The waveform of a pure tone without  
harmonics.  
Potentiometer (Pot)  
An electronic component that is used to provide variable  
control over an electronic circuit. It is usually controlled by a  
rotary knob which can be turned by hand; a volume control is  
a good example of this.  
Single-Ended  
An unbalanced line (see Unbalanced).  
Slew Rate  
Power  
Slew rate is the ability of a piece of audio equipment to  
reproduce fast changes in amplitude. Measured in volts per  
microsecond, this spec is most commonly associated with  
amplifiers, but in fact applies to most types of gear. Since high  
frequencies change in amplitude the fastest, this is where  
slew rate is most critical. An amp with a higher slew rate will  
sound “tighter” and more dynamic to our ears. Slew rates in  
amplifiers are often limited to useful levels to provide protec-  
tion to the amplifier from Radio-Frequency Interference (RFI).  
Literally, the rate at which energy is consumed. Power is  
expressed in Watts, abbreviated W. In electrical circuits,  
power is determined by the amount of resistance (R) times  
the amount of current squared with the following expression:  
P=I2R.  
Power Amplifier  
In audio, an electronic device that amplifies or increases the  
Amplifier Application Guide  
 
32  
Chapter 3: Glossary of Terms  
Sound Pressure Level (SPL)  
The acoustic volume or perceived loudness of sound, measured in  
although over-compression will result in a dull, squashed, flat sound  
to the signal.  
decibels. SPL is a function of a signal’s amplitude.  
Speakon®  
Trim  
Found on most mixers, trim controls provide the initial level setting  
for each channel’s input gain. In most cases, trim adjusts gain of the  
microphone preamp, but it may also apply to line level signals.  
A type (and brand) of multi-pin connector developed by Neutrik®  
which is now commonly found on speakers and amplifiers intended  
to be used in high power mobile applications. They have become  
popular because they offer a very high quality reliable connection,  
can handle extremely high power, are very durable, and are relatively  
low in cost compared to other similar connectors. Standard Speakon  
connectors come in four or eight conductor versions (though other  
configurations are available). The Speakon 8 has the same footprint  
as the EP8 connector and the Speakon 4 has the same footprint as  
XLR “D” type connectors.  
Unbalanced  
In electronics, a condition where the two legs of the circuit are not  
equal or opposite with respect to ground, usually because one leg  
is kept at ground potential. In other words: An audio signal requires  
two wires or conductors to function. In an unbalanced situation, one  
of those conductors is used to carry both signal and ground (shield).  
Unbalanced circuits are much more susceptible to induced noise  
problems than their balanced counterparts. Because of this, unbal-  
anced lines should be kept as short as possible (under 10-15 inches  
(25- to 38-cm)) to minimize potential noise problems.  
Stereo (Dual)  
An operating mode of an amplifier that allows channels of the  
amplifier to function independently.  
Unity Gain  
Switching Power Supply  
A device or setting which does not change signal level (does not  
amplify or attenuate a signal) is said to be at “unity gain.Many  
processors are set up for unity gain; that is, they can be plugged into  
a system without changing its overall levels. In practice, unity gain is  
often a desired setting for maintaining gain staging, and for optimizing  
operating levels and signal to noise ratios.  
A power supply that first converts AC mains power to a much higher  
frequency by means of a switching circuit before making the power  
available for use within the amplifier. The primary benefits of a switch-  
ing power supply are decreased overall unit weight and decreased  
electro-mechanical emissions.  
THD (Total Harmonic Distortion)  
Voltage  
The ratio of the power of the fundamental frequency at the output of  
a device versus the total power of all the harmonics in the frequency  
band at the output of the device. All electronic audio devices intro-  
duce some distortion to audio passed through them. The simplest  
form of this distortion is the addition of harmonics to the output signal.  
THD represents the sum of all the harmonics added by a device as a  
percentage of the level of the signal being measured.  
The electrical potential between two relative points in a circuit.  
Voltage is measured in volts (V). Ohms law defines voltage as the  
product of current (I) and Resistance (R) with the following expres-  
sion: V=I*R.  
VZ®  
VZ (Variable Impedance) is the name of Crown’s patented articulated  
power supply technology. VZ technology enables Crown to pack  
tremendous power into few rack spaces.  
Thermal Dissipation  
Energy not converted to the output of an amplifier is instead dis-  
sipated by the amplifier as heat.  
THX®  
Refers to a series of specifications for surround sound systems. Pro-  
fessional THX is used in commercial movie theaters.  
The VZ supply is divided into two parts. When the voltage demands  
are not high, it operates in a parallel mode to supply less voltage and  
more current. The power transistors stay cooler because they are  
not forced to needlessly dissipate heat. This is the normal operating  
mode of the VZ power supply. When the voltage requirements are  
high VZ switches to a series mode to produce higher voltage and less  
current. The amplified output signal never misses a beat and gets full  
voltage only when it requires it. Sensing circuitry observes the voltage  
of the signal to determine when to switch VZ modes. The switching  
circuitry is designed to prevent audible switching distortion to yield  
the highest dynamic transfer function.  
TLC  
TLC (Thermal Limit Control) is a circuit developed by Crown which  
provides amplifier thermal protection. When a predetermined temper-  
ature threshold is reached, the TLC indicator begins to glow to show  
that the temperature sensing circuitry is starting to engage the input  
compressor. By compressing the input, the amplifier will not gener-  
ate as much heat and will have a chance to cool down. The degree  
of compression is directly proportional to the amount of overheating  
experienced by the amplifier.  
To learn more about VZ, download and read the VZ white paper at  
Watt  
Transformer  
Power equates to the rate of energy transfer, or the rate of doing  
work. Power is measured in Watts, and the watt has become a  
common term in audio to describe the power handling capabilities  
and/or requirements of speakers, and the power delivery capabilities  
of amplifiers. Watts law defines power (P) as voltage (V) times current  
(I) with the following expression: P=V*I.  
A transformer is a device consisting of two or more coils of wire  
wound on a common core of magnetically permeable material. The  
number of turns in one coil divided by the number of turns in the  
other is called the turns ratio. An alternating voltage appearing across  
one coil will be inducted into the other coil multiplied by the turns  
ratio.  
XLR (Cannon or Three-Pin Connector)  
Transformers are used in power supplies, distributed speaker sys-  
tems, and are often used to provide electrical isolation in circuits to  
prevent ground loops because they pass AC voltages and block DC  
voltages.  
A three-pin professional audio connector used for balanced mic and  
line level signals. The AES standard for wiring of XLR connectors  
dictates that Pin 1 be soldered to the cable shield, pin 2 be soldered  
to the signal hot lead, and pin 3 be soldered to the signal return lead.  
The name XLR was trademarked by Cannon (now owned by ITT).  
XLR has since evolved into a generic industry term, and many manu-  
facturers now make this style connector.  
Transient  
A non-repeating waveform, usually of much higher level than the  
surrounding sounds or average level. Good examples of transients  
include the attack of many percussion instruments, the “pluck” or  
attack part of a guitar note, consonants in human speech (i.e. “T”),  
and so on. Due to their higher-than-average level and fleeting nature,  
transients are difficult to record and reproduce, eating up precious  
headroom, and often resulting in overload distortion. Careful use  
of compression can help tame transients and raise average level,  
Y-Adapter  
A single cable that divides into two cables in parallel to feed one  
signal to two destinations.  
Z
The abbreviation for impedance.  
Amplifier Application Guide  
 
Appendix: Suggested Reading  
33  
Appendix  
Suggested Reading  
his Appendix provides a a list of suggested publications for further reading  
Tabout professional audio.  
Audio Systems Design and Installation  
JBL Audio Enginering for Sound Reinforcement  
by John Eargle and Chris Foreman  
Paperback - 452 pages 1st edition (May 2002)  
Hal Leonard Publishing Corporation; ISBN 0-634-04355-2  
by Philip Giddings, Phillip Giddings  
Paperback - 574 pages (1990)  
Sams; ISBN: 0240802861  
Audio Systems Technology, Level I  
Sound Check :The Basics of Sound and Sound Systems  
by Tony Moscal  
Paperback - 104 pages (July 1994)  
by James S. Brawley (Editor), Larry W. Garter, National Sys-  
tems contractor, R. David Reed, National Sound Contractors  
Association  
Hal Leonard Publishing Corporation; ISBN: 079353559X  
Paperback - 295 pages (September 1, 1998)  
PROMPT Publications; ISBN: 0790611627  
Sound Reinforcement Engineering  
by Wolfgang Ahnert, Frank Steffen  
Hardcover - 424 pages (March 2000)  
Routledge; ISBN: 0415238706  
Audio Systems Technology #2 - Handbook For Installers  
And Engineers  
by James S. Brawley (Editor), Ray Alden, National Systems  
Contractors asso, Bob Bushnell, Matt Marth, NSCA  
Paperback - 415 pages (October 1, 1998)  
PROMPT Publications; ISBN: 0790611635  
Sound System Engineering  
by Don Davis, Carolyn Davis (Contributor)  
Hardcover - 665 pages 2nd edition (May 1997)  
Sams; ISBN: 0240803051  
Audio Systems Technology Level III: Handbook For  
Installers and Engineers  
by Bob Bushnell, Melvin J. Wierenga, Melvin J. Wierenga  
Paperback - 289 pages 1st edition (May 15, 2000)  
Howard W Sams & Co; ISBN: 0790611783  
Wire, Cable, and Fiber Optics for Video and Audio Engi-  
neers (McGraw-Hill’s Video-Audio Engineering Series)  
by Stephen H. Lampen  
Paperback - 350 pages 3rd edition (September 1997)  
McGraw-Hill; ISBN: 0070381348  
Handbook for Sound Engineers:The New Audio Cyclope-  
dia  
by Glen M. Ballou (Editor). Hardcover - 1506 pages 2nd edi-  
tion (January 1, 1991)  
Focal Press; ISBN: 0240803310  
Amplifier Application Guide  
 
NORTH AMERICA  
SUMMARY OF WARRANTY  
The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road, Elkhart,  
Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSE-  
QUENT OWNER of each NEW Crown product, for a period of three (3) years from the date of  
purchase by the original purchaser (the “warranty period”) that the new Crown product is free of  
defects in materials and workmanship. We further warrant the new Crown product regardless of  
the reason for failure, except as excluded in this Warranty.  
ITEMS EXCLUDED FROM THIS CROWN WARRANTY  
This Crown Warranty is in effect only for failure of a new Crown product which occurred within  
the Warranty Period. It does not cover any product which has been damaged because of any  
intentional misuse, accident, negligence, or loss which is covered under any of your insurance  
contracts. This Crown Warranty also does not extend to the new Crown product if the serial  
number has been defaced, altered, or removed.  
WHAT THE WARRANTOR WILL DO  
We will remedy any defect, regardless of the reason for failure (except as excluded), by repair,  
replacement, or refund. We may not elect refund unless you agree, or unless we are unable to  
provide replacement, and repair is not practical or cannot be timely made. If a refund is elected,  
then you must make the defective or malfunctioning product available to us free and clear of all  
liens or other encumbrances. The refund will be equal to the actual purchase price, not includ-  
ing interest, insurance, closing costs, and other finance charges less a reasonable depreciation  
on the product from the date of original purchase. Warranty work can only be performed at our  
authorized service centers or at the factory. We will remedy the defect and ship the product from  
the service center or our factory within a reasonable time after receipt of the defective product  
at our authorized service center or our factory. All expenses in remedying the defect, including  
surface shipping costs in the United States, will be borne by us. (You must bear the expense of  
shipping the product between any foreign country and the port of entry in the United States and  
all taxes, duties, and other customs fees for such foreign shipments.)  
HOW TO OBTAIN WARRANTY SERVICE  
You must notify us of your need for warranty service not later than ninety (90) days after expira-  
tion of the warranty period. All components must be shipped in a factory pack, which, if needed,  
may be obtained from us free of charge. Corrective action will be taken within a reasonable time  
of the date of receipt of the defective product by us or our authorized service center. If the repairs  
made by us or our authorized service center are not satisfactory, notify us or our authorized  
service center immediately.  
DISCLAIMER OF CONSEQUENTIAL & INCIDENTAL DAMAGES  
YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL DAMAGES RESULT-  
ING FROM ANY DEFECT IN THE NEW CROWN PRODUCT. THIS INCLUDES ANY DAMAGE  
TO ANOTHER PRODUCT OR PRODUCTS RESULTING FROM SUCH A DEFECT. SOME  
STATES DO NOT ALLOW THE EXCLUSION OR LIMITATIONS OF INCIDENTAL OR CON-  
SEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY  
TO YOU.  
WARRANTY ALTERATIONS  
No person has the authority to enlarge, amend, or modify this Crown Warranty.This Crown War-  
ranty is not extended by the length of time which you are deprived of the use of the new Crown  
product. Repairs and replacement parts provided under the terms of this Crown Warranty shall  
carry only the unexpired portion of this Crown Warranty.  
DESIGN CHANGES  
We reserve the right to change the design of any product from time to time without notice and  
with no obligation to make corresponding changes in products previously manufactured.  
LEGAL REMEDIES OF PURCHASER  
THIS CROWN WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, YOU MAY ALSO HAVE  
OTHER RIGHTS WHICH VARY FROM STATE TO STATE. No action to enforce this Crown War-  
ranty shall be commenced later than ninety (90) days after expiration of the warranty period.  
THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS CONTAINED IN THIS  
MANUAL FOR CROWN PRODUCTS.  
9/90  
 
WORLDWIDE  
SUMMARY OF WARRANTY  
The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road, Elkhart,  
Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSE-  
QUENT OWNER of each NEW Crown1 product, for a period of three (3) years from the date of  
purchase by the original purchaser (the “warranty period”) that the new Crown product is free of  
defects in materials and workmanship, and we further warrant the new Crown product regardless  
of the reason for failure, except as excluded in this Crown Warranty.  
1 Note: If your unit bears the name “Amcron,please substitute it for the name “Crown” in this  
warranty.  
ITEMS EXCLUDED FROM THIS CROWN WARRANTY  
This Crown Warranty is in effect only for failure of a new Crown product which occurred within  
the Warranty Period. It does not cover any product which has been damaged because of any  
intentional misuse, accident, negligence, or loss which is covered under any of your insurance  
contracts. This Crown Warranty also does not extend to the new Crown product if the serial  
number has been defaced, altered, or removed.  
WHAT THE WARRANTOR WILL DO  
We will remedy any defect, regardless of the reason for failure (except as excluded), by repair,  
replacement, or refund. We may not elect refund unless you agree, or unless we are unable to  
provide replacement, and repair is not practical or cannot be timely made. If a refund is elected,  
then you must make the defective or malfunctioning product available to us free and clear of all  
liens or other encumbrances. The refund will be equal to the actual purchase price, not includ-  
ing interest, insurance, closing costs, and other finance charges less a reasonable depreciation  
on the product from the date of original purchase. Warranty work can only be performed at our  
authorized service centers. We will remedy the defect and ship the product from the service  
center within a reasonable time after receipt of the defective product at our authorized service  
center.  
HOW TO OBTAIN WARRANTY SERVICE  
You must notify us of your need for warranty service not later than ninety (90) days after expira-  
tion of the warranty period. All components must be shipped in a factory pack. Corrective action  
will be taken within a reasonable time of the date of receipt of the defective product by our autho-  
rized service center. If the repairs made by our authorized service center are not satisfactory,  
notify our authorized service center immediately.  
DISCLAIMER OF CONSEQUENTIAL & INCIDENTAL DAMAGES  
YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL DAMAGES RESULT-  
ING FROM ANY DEFECT IN THE NEW CROWN PRODUCT. THIS INCLUDES ANY DAMAGE  
TO ANOTHER PRODUCT OR PRODUCTS RESULTING FROM SUCH A DEFECT.  
WARRANTY ALTERATIONS  
No person has the authority to enlarge, amend, or modify this Crown Warranty.This Crown War-  
ranty is not extended by the length of time which you are deprived of the use of the new Crown  
product. Repairs and replacement parts provided under the terms of this Crown Warranty shall  
carry only the unexpired portion of this Crown Warranty.  
DESIGN CHANGES  
We reserve the right to change the design of any product from time to time without notice and  
with no obligation to make corresponding changes in products previously manufactured.  
LEGAL REMEDIES OF PURCHASER  
No action to enforce this Crown Warranty shall be commenced later than ninety (90) days after  
expiration of the warranty period.  
THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS  
CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.  
9/90  
 

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