T
he Crown
®
14M and 28M are high-value
mixers for commercial and industrial audio.
The mixers are part of Crown’s Commercial
Audio Series, which also includes mixer-ampli-
fi ers and power amplifi ers. These low-cost units
provide all necessary features in a simple build-
ing-block format.
Some applications include schools, hospitals,
factories, restaurant/retail, houses of worship,
fi tness facilities, A/V boardrooms, prisons, and
small offi ces. Typical uses are paging, background
music, security and evacuation instructions.
The 14M has 4 inputs and 1 output channel.
The 28M has 8 inputs and 2 output channels.
Input routing allows each input to be assigned to
any output.
The sound system can be upgraded as a facility
expands. For example, you can add more mixers
for more inputs, or add more power amps (or
mixer-amps) to handle more zones.
Other features include priority muting and phan-
tom power.
Specifi cations
Performance
Frequency Response (at line out):
20 Hz to 20
kHz +/- 1 dB.
Signal to Noise Ratio (master volume at mini-
mum):
100 dB.
THD:
0.05% typical with 800 mV balanced input,
1V output.
Input Sensitivity (volts RMS for full output at
maximum gain):
Balanced mic inputs: 3 mV.
Balanced line inputs: 800 mV.
RCA connectors: 400 mV.
Input Impedance (nominal):
Mic: 400 ohms.
Line: 100 kilohms.
RCA: 50 kilohms.
Crosstalk (all controls at “10”):
–50 dB at 1kHz.
Line Output Level (nominal):
1.2 V into 10
kilohms.
Phantom Power:
15 VDC.
AC Line Voltages Available:
100V 50/60 Hz
120V 60 Hz
220V 50/60 Hz
230V 50/60 Hz
240V 50/60 Hz
Operating Temperature/Humidity:
0° C to 40° C
at 95% relative humidity (non-condensing).
Storage Temperature:
–20° C to 85° C.
Front Panel Controls and Indicators
Power Switch:
Pushbutton on-off switch. The
power switch does not affect the 24V DC auxiliary
power input.
Input Volume Controls:
Microphone/line, four in
14M, eight in 28M. Detented potentiometers with
knobs.
Tone Controls:
Bass and Treble non-detented
potentiometers on each input channel. Bass ±10
dB at 100 Hz, Treble ±10 dB at 10 kHz.
Power Indicator:
Blue LED indicates power on.
Input Signal Presence Indicator:
Green LED, one
for each input channel, illuminates when input
signal exceeds –24 dBu (line) or –70 dBu (mic).
Output Signal Presence Indicator:
Green LED,
one for each output channel, illuminates when
output signal level exceeds 100 mV.
Clip Indicators:
Red LED, one per output channel.
Illuminates at threshold of audible distortion.
Output Volume Controls:
One per output channel.
Detented potentiometer with knob.
Back Panel Controls and Connectors
Fuse:
Protects the power supply.
AC Power Inlet:
Detachable IEC.
Auxiliary Power Input:
2-position terminal strip
for 24 VDC (±10%) backup power. Accepts up to
10 AWG terminal forks.
Mixer Confi g Switch:
A DIP switch with two
functions:
1. Assigns an input as the priority input for each
output, thereby temporarily muting the remaining
inputs. Muting is activated by contact closure.
2. Global enable switch for phantom power. Does
not affect RCA inputs. Default position is off.
Priority Connector:
3-pin Phoenix-type connec-
tor allows Input 1 or Input 5 (28M only) to mute
other input signals by contact closure.
Input Routing Switch (28M only):
DIP switches
that assign each input signal to each output. Two
switches per input.
Line Out Connector:
One 3-pin balanced Phoenix-
type connector per output channel. Level con-
trolled by master volume control.
Input Connectors:
Mic/Line Connector: 3-pin Phoenix-type, bal-
anced, one per input channel.
Dual RCA Input Connector: For stereo music
signals, unbalanced, summed together, two con-
nectors per input channel.
The tone generator has been omitted. Call Crown
Tech Support if you have a tone generator ques-
tion.
Mic/line Switch:
Selects mic-level or line-level
signals. One switch for each balanced input.
C O M M E R C I A L A U D I O S E R I E S
• 4 or 8 inputs, 1 or 2 output channels
• Ideal for commercial and industrial use
• Balanced Phoenix-type mic/line inputs; RCA
inputs
• Balanced Phoenix-type line outputs
• Any input can be sent to any output
• Priority muting
• Independent bass and treble controls for
each input
• Three-Year, No-Fault, Fully Transferable
Warranty completely protects your invest-
ment and guarantees its specifi cations
Features
B
T
B
T
B
T
B
T
B
T
T
B
B
T
B
T
MASTER 1
MASTER 2
POWER
SPI
CLIP
SPI
CLIP
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
20
0
1
0
5
5
1
1
2
3
4
5
6
7
8
14M
28M
