Crunch DRA1150.2, DRA1450.4, DRA4050.2, DRA1050.4, DRA2450.4 User Manual
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AMPLIFIERS
DRIVE
DRA850.2 / DRA1150.2 / DRA4050.2
DRA1050.4 / DRA1450.4 / DRA2450.4 / DRA4050.4
DRA1850.1D / DRA2550.1D / DRA3250.1D
GENERAL INSTALLATION PROCEDURE
System Design
Installation
The success of any car stereo system relies on several factors, such as the system design, execution of the installation, and system setup. Please
remember that any system is only as good as its weakest link.
Please remember that higher power systems are not necessarily useful purely for high sound pressure levels, but also to establish a headroom capability, to
reproduce musical peaks cleanly without distortion. Lower power amplifiers will clip earlier than their more powerful cousins, and cause loudspeaker failure when
overdriven, due to the harmonics generated by a clipped signal, thus overheating voice coils.
Amplifiers should be mounted with the fins running horizontally for best convection cooling, to minimize overheating. Purchase the best quality RCA cables you can
afford, for reliability and less engine noise interference in the audio system.
General:
Run the wiring so that RCA cables are at least 18“ away from power and speaker cables. Keep RCA cables away from electrical devices in the vehicle that can cause
electrical noise, such as electric fuel pumps, emission control modules and other on-board electronic modules.
Power and ground connections(see the features matrix on page 9 for proper gauge cables per amplifier):
Use a sufficient gauge power cable and ground cable using the chart below as reference to what size wire you require. In a multi amplifier system, add the total value
of the manufacture recommended fusing to get your total system amperage. Some applications may require multiple runs of power wire to meet the system
requirements. In multi amplifier systems it is advisable to mount a large enough fuse right at the battery, and run one or multiple +12 volt power cables to a fused
distribution block near the amplifiers. It is then a simple matter to connect the +12 volt terminal of each amplifier to the distribution block. During this process, please
ensure that the main power fuse is removed to avoid shorting the electrical system. The main fuse must be within 12” of the vehicles battery.
Ground each amplifier with as short a ground lead as possible directly to the vehicle chassis using 4 gauge wire or equivalent to the size of the amplifiers’ power wire.
Use a ground distribution block, if you wish, but it is extremely important to keep the main ground lead from this distribution block to the chassis as short as possible ,
not more than 12“. The ground connection integrity to the chassis is very important, and the best way to achieve a good, solid electrical and mechanical contact is to
use a large round crimp lug, crimped and soldered to the ground cable. The next step is to scrape the paint off the vehicle chassis , slightly larger than the ground
lug, at the connection point. Drill a clearance hole in the chassis, the same size as the lug hole, and use a bolt, spring washer and nut to securely fasten the ground
lug. Use petroleum jelly to coat the bolt/lug connection, to prevent oxidization with time.
TIP: Use the same approach when installing head units, equalizers or any audio equipment for that matter - run short individual grounds from each piece directly to
the vehicle chassis, to minimize ground loops and system noise. All power, ground and speaker connections should be crimped and soldered for reliability. Make sure
that none of the cable insulation can chafe against exposed metal in the vehicle, causing short circuits to the chassis.
Safe connection sequence:
After all cables are run, connect speaker wires to the speakers and amplifiers, then run and plug in RCA cables. Next, connect all power, ground, and remote turn on
leads. Now connect all +12 volt cables to the amplifier/s and distribution blocks and fuse holders. Finally, connect the main +12 volt cable to the battery, with the main
fuse removed, and we are almost ready to power up the system.
Power up the system:
The following procedure may seem like overkill, but there is nothing more frustrating when turning on a system for the first time, and it does not work properly
immediately.
First, make sure the head unit is off, and turn all level controls to minimum (counterclockwise), including the head unit volume control. Set all equalizers to 0 dB (no
boost), and all crossover frequency controls at approximate frequencies, as recommended by the loudspeaker manufacturer. Set all input selector and crossover
switches as required for the application. Remove all amplifier fuses, and insert the main fuse at the battery. If the fuse does not blow, you can insert the fuse in one of
the amplifiers, and we are ready to turn on the system. Turn the head unit on, insert a CD, or select a radio station, and increase the head unit volume control. If the
system sounds fine, turn off the head unit, and install fuses in the remaining amplifiers, one by one, till the complete system is powered up and functioning properly.
It is highly recommended that the amplifier be mounted to a board of MDF or other solid
structure using the 4 mounting screws provided. Avoid mounting the
amplifier to metal as this can introduce noise and other unwanted issues. When mounting
the amplifier, ensure that it is mounted HORIZONTALLY, as shown in the diagram above, for
optimal heat dissipation. Mounting amplifiers to speaker enclosures is not recommended as
this can cause damage to the amplifier components. When choosing a location for
mounting the amplifier, ensure that you check for clearance from wires, gas tank, electrical
devices and brake lines etc.
7-10 ft. 10-13 ft. 13-16 ft.
16-19 ft. 19-22 ft. 22-28 ft.
SYSTEM
AMPERAGE
35-50
50-65
68-85
85-105
105-125
125-150
8
6
4
4
4
2
6
4
4
2
2
0
4
4
2
2
0
0
4
4
2
2
0
0
4
4
2
2
0
0
4
2
0
0
0
0
WIRE LENGTH
WIRE GAUGE
WOOD
DRIVE
AMPLIFIER FEATURE DESCRIPTIONS
V DRIVE AMPLIFIERS:
Each model is capable of 4 & 2-Ohms stereo per channel, or 4-Ohms mono bridged operation except All Crunch amplifiers feature a comprehensive diagnostic system, with speaker lead short circuit, and
amplifier DC faults indicated by the red “PROTECT” LED.
the mono amps which are capable of 4, 2 and 1-Ohm loads.
CAUTION: DO NOT OPERATE ANY AMPLIFIER BELOW THE INTENDED IMPEDANCE. YOU
The input sensitivities for rated output powers are variable from 0.2 volts to 6 volts.
WILL CAUSE DAMAGE TO THE AMPLIFIER THAT WILL NOT BE COVERED UNDER THE
All crossovers are fully variable in their respective ranges.
Crossover filters are 12dB/Octave.
WARRANTY PRINTED IN THE BACK OF THE MANUAL. 2 & 4 Channel amps are capable of 4
A POWER LED indicates the powered up and turned on condition
and 2-Ohms wired stereo and 4-Ohms wired mono bridged. The mono amps are capable of 4, 2
and 1-Ohm.
The 4 channel amps have the same features as the 2 channel models except that there are 2 sets of
controls.
1 set for channels 1 & 2 and 1 set for channels 3 & 4.
In addition, the 4 channel models have a MODE switch which allows for RCA signal routing and
selection.
The X-OVER slide switch selects the internal crossover functions:
-The input signal is routed directly to the LINE OUT RCA jacks, regardless of the X-OVER setting
simplifying daisy chaining of amplifiers.
-HPF: Selects the built in HIGH PASS filter, variable from 60 Hz to 1.2kHz.
-FULL: Bypasses all crossovers for full frequency range operation.
-LPF: Selects the built in LOW PASS , variable from 30 Hz to 250Hz.
MODE: The mode switch allows you to choose routing of signal within the amp.
-2CH Mode: In this mode, only inputs 1&2 are used. Input 1 (left)is internally routed to speaker
terminals 1&3, while input 2 (right)is internally routed to speaker terminals 2&4.
This is useful when only a stereo source is available. CH1&2 can be set to high pass for highs, and
CH3&4 to low pass for lows, for instance, or set to full range, depending on the application.
-3CH mode: In this mode, input 1&2 signals are internally mono mixed, and routed as a mono signal
to 1&2 speaker terminals. These outputs can be mono bridged into one speaker. Set CH1&2 to low
pass. Input 3 is internally routed to speaker terminal 3, and input 4 is internally routed to speaker
terminal 4. Set CH3&4 to high pass.
-4CH Mode: In this mode, each input is internally routed to the corresponding speaker terminals,
with input 1 to speaker terminal 1 etc.
HIGH INPUT: If your radio/CD player does not have unbalanced (RCA) outputs, you can use the
HIGH level (wire) inputs.
LINE INPUT: The line input accepts unbalanced (RCA) inputs from 0.2V to 6V.
LINE OUTPUT: The line output passes through signal from the line inputs which allows you to daisy
chain multiple amplifiers from one signal.
Note that the LOW PASS signal is MONO.
-In the LPF position, the HIGH PASS filter acts as a subsonic
filter.
-When the LPF mode is selected a 0 to +12dB, at 45Hz,
BASS EQ is also switched in.
DRA1050.4 / DRA1450.4 / DRA2450.4 / DRA4050.4
4-CHANNEL AMPLIFIERS
FLASH
NO FLASH
MODE
X-OVER X-OVER
2CH 3CH 4CH
FULL
HPF
LPF
CH3
CH4
CH1
CH2
INPUT
OUTPUT
INPUT
HPF
LPF
FULL
GND
CH1
GND
CH2 CH3 CH4
HIGH INPUT
BASS EQ
0dB
12dB
6V 0.2V
6V 0.2V
30Hz
250Hz
LPF
60Hz
1.2kHz
HPF
LEVEL
CHANNEL 1/2
LEVEL
BASS EQ
0dB
12dB
HPF LPF
CHANNEL 3/4
60Hz
1.2kHz
30Hz
250Hz
The X-OVER slide switch selects the internal crossover functions:
-The input signal is routed directly to the LINE OUT RCA jacks, regardless of the X-OVER setting
simplifying daisy chaining of amplifiers.
-HPF: Selects the built in HIGH PASS filter, variable from 60 Hz to 1.2kHz.
-FULL: Bypasses all crossovers for full frequency range operation.
-LPF: Selects the built in LOW PASS , variable from 30 Hz to 250Hz.
MODE: The mode switch allows you to choose Stereo for full range 2 channel operation or MONO
for bridging operation
HIGH INPUT: If your radio/CD player does not have unbalanced (RCA) outputs, you can use the
HIGH level (wire) inputs.
LINE INPUT: The line input accepts unbalanced (RCA) inputs from 0.2V to 6V.
LINE OUTPUT: The line output passes through signal from the line inputs which allows you to daisy
chain multiple amplifiers from one signal.
Note that the LOW PASS signal is MONO.
-In the LPF position, the HIGH PASS filter acts as a subsonic
filter.
-When the LPF mode is selected, a 0 to +12dB, at 45Hz, BASS
-EQ is also switched in.
DRA850.2 / DRA1150.2 / DRA4050.2
2-CHANNEL AMPLIFIERS
FULL
LPF
MODEX-OVER
BASS EQ
0dB
12dB
HPF LPF
HPF
60Hz
1.2kHz
30Hz
250Hz
STEREO
MONO
L
R
L
R
LINE OUT
LINE INPUT
FLASH
NO FLASH
GND
HI INPUT
LEVEL
6V 0.2V
-SUBSONIC: Allows you to adjust the crossover filter from 15Hz to 35Hz.
-LPF: Allows yo to adjust the LOW PASS crossover filter from 30Hz to 250Hz.
LEVEL: Adjusts the input sensitivity from 0.2 volts to 6 volts.
BASS EQ: The Bass EQ is adjustable from 0db to 10dB.
REMOTE: This is the input jack for the remote Level control.
LINE INPUT: The line input accepts unbalanced (RCA) inputs from 0.2V to 6V.
LINE OUTPUT: The line output passes through signal from the line inputs which allows you to daisy
chain multiple amplifiers from one signal.
The mono amps are capable of 4, 2 & 1-Ohm loads.
Operating the amp below 1-Ohm can cause damage to the
amp not covered in the warranty.
DRA1850.1D / DRA2550.1D / DRA3250.1D
1-CHANNEL D CLASS MONO BLOCK AMPLIFIERS
FLASH
NO FLASH
30Hz 250Hz
LOW PASS
L
R
L
R
OUTPUT
INPUT
LEVEL
BASS EQ
0dB6V 0.2V
10dB
CONTROL
REMOTE
15Hz
35Hz
SUB SONIC
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