Specifications
INSTALLED SOUND
`SPECIFICATIONS
Power
Load Impedance: Safe with all types of loads.
CH1: 4 and 8 ohm Stereo; 16 ohm at 70V Stereo;
32 ohm at 100V Stereo; 8 and 16 ohm Bridge;
32 ohm at 140V Bridge; 64 ohm at 200V Bridge.
CH2: 4 and 8 ohm Stereo; 8 ohm at 70V Stereo;
16 ohm at 100V Stereo; 8 and 16 ohm Bridge;
16 ohm at 140V Bridge; 32 ohm at 200V Bridge.
CH4: 4 and 8 ohm Stereo; 4 ohm at 70V Stereo;
8 and 16 ohm Bridge; 8 ohm at 140V Bridge.
Voltage Gain, 1 kHz, 1.4V sensitivity,
CH1: 30.5 dB (4/8 ohm); 34 dB (70V); 37 dB (100V).
CH2: 32.1 dB (4/8 ohm); 34 dB (70V); 37 dB (100V).
CH4: 34 dB (4/8 ohm); 34 dB (70V).
AC Line Requirements: CL1, CL2: 60 Hz. CL4:
50/60 Hz.
AC Line Current (no signal):
CH1: 100 Volts: 7.6 A; 120 Volts: 6.3 A;
230-240 Volts: 3.5 A.
CH2: 100 Volts: 11.4 A; 120 Volts: 9.5 A;
230-240 Volts: 5.0 A.
CH4: 100 Volts: 8.5 A; 120 Volts: 7.1 A;
230-240 Volts: 3.7 A.
AC Line Connector: Detachable 15A IEC connector
with country-specific plug.
Performance
Frequency Response, 20 Hz to 20 kHz at 1 watt:
CH1, CH2: ±0.1 dB.
CH4: ±0.25 dB.
Phase Response: ±15 degrees from 20 Hz to 20
kHz at 1 watt.
Signal to Noise Ratio, A-Weighted,
CH1, CH2: Better than 105 dB below rated
1-kHz power.
CH4: Better than 102 dB below rated 1-kHz power.
Total Harmonic Distortion (THD) at rated power:
0.5% or less.
Intermodulation Distortion (60 Hz and 7 kHz at 4:1):
CH1, CH2: Less than 0.1% at rated power to 30 dB
below rated power at 8 ohms.
CH4: Less than 0.5% at rated power to 30 dB
below rated power at 8 ohms.
Damping Factor (8 ohm),
CH1, CH2: Better than 600 from 10 Hz to 400 Hz.
CH4: Better than 1000 from 10 Hz to 400 Hz.
Crosstalk, 20 Hz to 20 kHz:
CH1, CH2: Better than 50 dB below rated power.
CH4: Better than 50 dB below rated power at 10 kHz.
Common Mode Rejection (CMR): Better than
40 dB from 20 Hz to 1 kHz.
DC Output Offset (Shorted Input): ±10 mV.
Controls
Level: A detented rotary level control for each
channel located on the rear panel.
Power: An on/off rocker switch located on the
front panel.
Mode: Two-position switch. “Stereo” operates the
amplifier as two independent channels. “Bridge”
bridges the two output channels for twice the out-
put voltage.
Channel Operation Switch: Two-position switch:
“4/8 Ohm” drives low-impedance speaker loads.
“70V/100V” (70V only on the CH4) drives distrib-
uted high-impedance speaker loads; inserts 70-Hz
high-pass filter to prevent step-down transformer
saturation.
Indicators
Signal: A green indicator for each channel which
flashes when a very low-level signal (> –40 dBm) is
present at input. May be used for troubleshooting
cable runs.
Clip: A red indicator for each channel which turns
on when distortion becomes audible in the ampli-
fier output.
Fault: A red indicator for each channel which indi-
cates amplifier has muted output. Normally off.
Status may be monitored remotely by plugging into
back-panel RJ11 Fault jack.
Power: A blue indicator that turns on when the
amplifier has been turned on and has power.
Input/Output
Input Connector (standard module): One Neutrik
Combo connector for each channel (balanced ¼-
inch [6.35-mm] phone jack and 3-pin female XLR
connector, in parallel with a barrier strip termination).
Input Stage: Electronically balanced with precision
1% resistors.
Input Impedance: Nominally 20 k ohms balanced.
Nominally 10 k ohms unbalanced.
Input Sensitivity: Channel independent. Factory
set at 1.4 volts for standard 1-kHz, 8-ohm power.
26-dB gain and 0.775-volt sensitivity available as
a Service Option.
Output Connectors
CH1 and CH2: Four-terminal touch-proof barrier
block, one per channel, connects to 8-ohm, 4-
ohm, 70V or 100V outputs.
CH4: Four-terminal touch-proof barrier block.
Output Signal,
Stereo: Unbalanced, two-channel.
Bridge-Mono: Balanced, single-channel. Channel 1
controls are active; Channel 2 should be turned
down.
Protection
Protected against shorted, open or mismatched
loads; overloaded power supplies; excessive tem-
perature, chain destruction phenomena, input
overload damage and high-frequency blowups.
They also protect loudspeakers from input/output
DC, large or dangerous DC offsets and turn-
on/turn-off transients.
Construction
Rugged steel chassis, coated with environmen-
tally friendly powder for long life and ease of
maintenance.
Cooling: Proportional speed fan.
Dimensions
Width (all models): EIA Standard 19-inch rack
mount (EIA RS-310-B).
Height (all models): 5.25-inch (13.34-cm).
Depth (behind front mounting surface):
CH1, CH2: 12.25-inch (31.11-cm);
CH4: 16.25-inch (36.56-cm).
Weight
CH1: 40.6 pounds (18.4 kg);
CH2: 48.3 pounds (21.9 kg);
CH4: 33.3 pounds (15.1 kg).
For shipping weight, add 6 pounds (2.7 kg) to each
amplifier’s weight.
System Solutions
SST Modules: SST-SBSC: variable Linkwitz-Riley
stereo crossover with mono-summed sub-bass
outputs;
ScreenArray
®
SST modules.
Regulatory Certifications
Note: All measurements apply to all models of CH
series amplifiers in stereo mode with 8-ohm loads and
an input sensitivity of 26-dB gain, 1-kHz at rated power
unless other otherwise specified. Specifications for
units supplied outside the U.S.A. may vary slightly at
different AC voltages and frequencies.
A
s part of the Contractor (CH/CL) Series, Crown delivers three models
(CH1, CH2 and CH4) designed for both low and high impedance outputs
per channel, with each channel independently capable of providing 4/8-ohm,
70V or 100V operation. The powerful and flexible CH Series amplifiers also
include 70-Hz high pass filters on each channel, giving you the necessary
low frequency rolloff to eliminate the saturation of constant voltage step-
down transformers typically used in 70V and 100V distributed systems.
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