Power bass ATM 900.1D User manual

ATM COMPACT CLASS D AMPLIFIER
Owners Manual
Please read through this manual to familiarize yourself with your new amplifier. Should your PowerBass
AutoSound mobile amplifier ever require service, you will need to have the original dated receipt.
ATM 600.1D
ATM 900.1D

Thank you and Congratulations
Thank you for your decision to purchase a PowerBass USA Autosound mobile amplifier! Our Autosound
amplifiers are the result of extensive engineering, testing, and bullet proof construction. They feature the
latest in D Class microprocessor technology. Their versatility enables compatibility with optional signal
and audio processors. These high quality MOSFET amplifiers may be configured to allow maximum flex-
ibility in designing different subwoofer options.
COMPACT CLASS D AMPLIFIERS
All PowerBass ATM series Class “D” models are single channel dedicated subwoofer amplifiers. Unlike
most Full Range amplifiers, these models are designed specifically for low frequencies and are intended
only to power subwoofers. It is important that you closely follow the wiring instructions contained in this
Owners Manual so that you get the most from your PowerBass AutoSound D Class mobile amplifier.
∆Caution ∆
High powered audio systems in a vehicle are capable of generating higher then “Live Concert” levels of sound pressure. Continued
exposure to excessively high volume sound levels will cause hearing loss or damage. Also, operation of a motor vehicle while listening
to audio equipment at high volume levels may impair your ability to hear external sounds such as horns, warning signals, or emergency
vehicles—thus creating a potential traffic hazard. In the interest of safety, PowerBass USA highly recommends listening at lower volume
levels when driving.

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TECHNICAL FEATURES
• Mono Block Amplifier for Subwoofer
• Latest Class D Technology
• High and Low Level Line Input
• Double Sided Circuit Board Construction
• MOSFET Power Supplies for High Power Output and Best Stability into Low Impedance Loads
• Soft Delay Remote Turn On/Off Circuit to Eliminating Pops and Clicks
• Variable Low Pass Electronic Crossover
• Built-in Fully Adjustable Bass Boost
• Self Diagnostic Protection Circuit with LED Status Indicator for; Impedance Over-load, Speaker Short
Circuit, Thermal Overheating, and DC Output.
• Real 1-ohm Stable Operation with Extensive Output Power Increase
• Custom Tooled Solderless Speaker and Power Terminal Blocks
• Variable Gain Control
• Pass Thru Line Output Jacks
• Remote Gain Control (Included)
INSTALLATION EXPERIENCE
Installation of PowerBass mobile amplifiers requires detailed knowledge of electronics wiring and proper
speaker impedance. We strongly recommend installation by an authorized PowerBass dealer. This Own-
ers Manual only provides general installation and operation instructions. If you have any reservations
about your installation skills, please contact your local PowerBass dealer for assistance.
IMPORTANT : This amplifier is designed for operation in vehicles with 12-volt Negative ground
electrical systems only.
PREPARING FOR INSTALLATION
NOTE: The tools listed below may be required for basic installation
• An electric drill with bits
• Philips head and standard screwdrivers
• Wire strippers
• Crimping tool
• VOM (electronic volt ohm meter)
• Heat shrink tubing and heat gun
• Soldering iron
• Electronic (not Acid Core) Solder

INSTALLATION PRECAUTIONS
NOTE: Proceed only if you are a qualified installer, otherwise; see your Authorized PowerBass
Dealer to professionally install this amplifier. Always wear protective eyewear when using
tools.
• Turn off all stereo and other electrical devices before you begin.
• Disconnect the negative (-) lead from your vehicles battery.
• Locate all fuel lines, brake lines, oil lines, and electrical cables when planning the install.
• Make sure there is at least 2-inches (5 cm) around the air vents on the amplifier.
• When connecting ground points, make sure all paint is carefully scrapped away from the vehicle’s
chassis and contact is make with bare metal.
• Use a utility knife to trim away fabric from hole locations before drilling or cutting.
• When running power cables through sheet metal, be sure to use grommets to properly insulate the
metal edges from the wire insulation.
• If possible, use tubing through grommets.
Due to the high power output of the PowerBass Autosound Class D amplifiers, considerable heat may be
produced when the unit is in operation. For this reason the amplifier should be mounted in a location
which will allow air to circulate freely. A clearance of at least 2-inches (5 cm) to all sides of the amplifier
is necessary not only for proper cooling, but also for gaining access to the inputs and other variable
controls. Be sure that the power and signal cable connections can enter and leave the amplifier in a
straight line to avoid the risk of kinked wires causing malfunction.
Fig.1 Mounting Amplifier
MOUNTING THE AMPLIFIER

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MOUNTING LOCATION
Find a clear and well ventilated area to mount your amplifier that is unobstructed by any objects that will cause
harm or block ventilation. Despite the fact that this amplifier is compact, it still needs air to cool the heatsink
fins. Do not mount under a carpet or an area with dead or stagnant air. Without proper air flow the amplifier
may overheat and go into protection where the thermal overload circuitry will shut down the amplifier.
You may use the amplifier as a template and mark the four screw locations with a felt tip pen. Set the amplifier
aside before drilling. Use caution to make sure there are no objects behind the installation surface that may
become damaged during drilling.
The amplifier should be protected from exposure to moisture and direct sunlight. The best places to mount
your amplifier are: The floor of the trunk, under the driver’s seat, or on the back of the rear seat. For alternate
installation locations, please consult your authorized PowerBass Dealer.
NOTE: Do not use a drill with driver bit to mount the amplifier. Excessive force could cause
the plastic mounting feet to crack.
*** WARNING ***
• Upside down mounting will compromise heat dissipation through the heatsink and
could engage the thermal protection circuit.
• Try to avoid mounting the amplifier on a subwoofer enclosure, as extended exposure
to vibration may cause malfunction of the amplifier.
• Don’t mount the amplifier so that the wire connections are unprotected or are sub-
ject to pinching or damage from nearby objects.
• The DC power wire must be fused at the battery positive (+) terminal connection.
Before making or breaking power connections at the amplifier power terminals,
disconnect the DC power wire at the battery end.
• The battery of the car audio system must be disconnected until the entire wiring and
installation is completed.
• Don’t use a power drill to tighten the power, ground, remote or speaker output
terminals on the amplifier to avoid stripping the terminal screws. It is best to hand
tighten these connections.

CONTROL PANEL LAYOUT
1. POWER Indicator
The clear L.E.D. lights BLUE when the power is on.
2. STATUS Indicator
This L.E.D. turns RED when the built-in protection circuitry is activated. This indicates a problem with the
system in relation to the amplifier (see Troubleshooting Tips).
3. REMOTE Gain
This is the connector port for the Remote Gain Control. Now the amplifiers secondary gain circuit can be
adjusted from the driver’s seat.
4. HIGH INPUT
Allows you to connect speaker output from factory radio to amplifier without the use of a low level convertor.
Fig.2 Panel Layout

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5. LINE OUT (RCA) Jacks
RCA style pass through output jacks allow for a signal to be sent to other amplifiers in a daisy-chain configura-
tion. Only one Remote Bass Control can be used when multiple bass amplifiers are connected.
6. LINE IN (RCA) Jacks
These RCA style input jacks are for use with source units that have RCA line level outputs. A source unit with
a minimum output of 500mV is required for proper operation. However, this input will accept levels up to
4Vrms.
7. GAIN Control
This control is used to match the input sensitivity of the amplifier to the particular source unit that you are
using up to 5 volts.
8. LPF (Low Pass Filter) Control
This filter controls low pass of frequencies and is adjustable from 40Hz through 180Hz to eliminate unwanted
high frequencies.
9. SUB SONIC Control
This control is continuously adjustable from 17Hz through 50Hz at 12dB per octave to provide an extra level of
subwoofer protection from bass robbing power at unheard frequencies.
10. BASS FREQ
This control is variable from 30Hz to 80Hz and allows you to choose the exact frequency you want to boost
using the BASS EQ feature.
11. BASS EQ Control
This equalization circuit is used to enhance the low frequency response of the vehicle’s interior. With up to
18dB of boost, the BASS BOOST can be adjusted to meet your own personal taste.
12. SPEAKER Output Terminals
As shown in the wiring diagrams, be sure to observe speaker polarity through the system and speaker imped-
ance. This specially tooled terminal is designed to accommodate up to 10 gauge speaker wire.

13. FUSES
For convenience most PowerBass AutoSound amplifiers utilize common automotive ATC type fuses. For con-
tinued protection in the event that a fuse blows, replace the fuse only with the same value. CAUTION: These
power fuses on the amplifier chassis are for protecting the amp against over current situation. To protect the
vehicles electrical system, an additional fuse should be used within 18-inches of the battery on the 12V+
cable.
ATM 600.1D 25A x 3
ATM 900.1D 30A x 3
14. BATT+ (Power Input Terminal)
This terminal is the main power input for the amplifier and must be connected directly to the positive (+) termi-
nal of the car battery. (see Power Cable Selection Chart for recommended wire gauge for each model).
15. REM (Remote Input Terminal)
All PowerBass AutoSound amplifiers can be turned on by applying 12 volts to this terminal. This can be found
on the rear of the source unit in the form of an electric antenna output, or a remote output. If this is not avail-
able you can wire to the ACC position on the key. An 18 gauge wire is sufficient to run the REMOTE.
16. GND (Ground Input Terminal)
A good quality ground is required for your PowerBass AutoSound D Class amplifier to operate at peak per-
formance. A short length of cable the same gauge as your power cable should be used to attach the ground
terminal directly to the chassis of the vehicle. Make sure that all of the paint is sanded or scraped away to
ensure a quality ground connection

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This amplifier is designed to work within a 10 to 16.5 volt DC range. Before any wires are connected, the
vehicles electrical system should be checked for correct voltage supply with the help of a voltmeter.
First, check the voltage at the battery with the ignition in the OFF position. The voltmeter should read no
less than 12V. If your vehicles electrical system is not up to these specifications, we recommend having it
checked by an auto electrician before any further installation. Once the vehicle is checked, make certain the
correct cable gauge is used. We recommend using as large a gauge cable as possible, use the Power Cable
Selection Chart to calculate the correct power wire size for your application. Remember Bigger is Better!
*** WARNING ***
Disconnect the negative (-) battery terminal before you start any wiring work! The bat-
tery of your car audio system must be disconnected until the entire wiring installation is
completed.
Your PowerBass Autosound Class D amp will draw large levels of current, so use the largest gauge power/
ground cable as possible. Using too small of power cable can result in unnecessary over-heating of the
amplifier, distortion at high volume levels and might even cause the thermal protection circuitry to shut-off
the amplifier. Remember, bigger wire is better! For best results we recommend a PowerBass amplifier install
kit, available at your local PowerBass dealer.
• Use rubber grommets when running cables through any metal or sharp plastic, to prevent accidental
shorting or shearing. Make sure the cables do not interfere with normal operation of the vehicle.
• The audio signal cables (RCA interconnects) should be kept far away from any potential sources of
electrical interference such as electronic vehicle management systems (relays, engine computers wir-
ing harnesses, fuel pumps etc.)
POWER WIRING AND SIGNAL CONNECTIONS
Fig.3 Power Input Connection

BATT+ (Power)
This amplifier should be wired directly to the vehicle battery using the appropriate size cable. Start at the
vehicle battery and run the power cable through to the amplifier. Avoid running the power cable over engine
components and near heater cores. The use of an inline fuse or circuit breaker is a must; this will prevent
the risk of a potential fire caused by a short in your power cable. Connect the fuse holder or circuit breaker
as close to the battery positive (+) terminal as possible (no farther then 18” from that battery). This fuse or
circuit breaker should be no greater then the sum of the fuses found on the chassis of your amplifier (also
see specifications chart). You may now connect the cable to the battery, but remember to leave the fuse out
or circuit breaker “off” until all other cable connections are made.
GND (Ground)
When grounding your amplifier, locate a metal area close to the amplifier that is good source of ground
(preferably the floor pan). Once again, investigate the area you wish to use for electrical wires, vacuum lines,
and brake or fuel lines. Use either a wire brush or sandpaper to eliminate unwanted paint for better contact
of the ground.
Secure the ground cable to the body using a bolt, star washer and nut. Spread silicon over the screw and
bare metal to prevent rust and possible water leaks.
Now it’s time to connect the power and ground cables to the amplifier. Cut both cables to length.
Strip off 1/2 inch (12mm) of the insulation so that the bare wire fits all the way in the terminal block on the
side panel of the amplifier, seating it firmly so no bare wire is exposed. Use a Philips screwdriver to loosen
the BATT+ and the GND connections on the amplifier. Insert the ground first, and then the +12V and please
make sure that you place them into the correctly marked terminals. Then tighten the screws down securely.

Now it’s time to connect the power and ground cables to the amplifier. Cut both cables to length.
Strip off 1/2 inch (12mm) of the insulation so that the bare wire fits all the way in the terminal block on the
side panel of the amplifier, seating it firmly so no bare wire is exposed. Use a Philips screwdriver to loosen
the BATT+ and the GND connections on the amplifier. Insert the ground first, and then the +12V and please
make sure that you place them into the correctly marked terminals. Hand tighten the set screws and make
sure the connection secure to prevent possible arcing due to loose screws.
REM (Remote Trigger)
This terminal must be connected to a switched +12V source. Typically, remote turn-on leads are provided
at the source unit that will turn on and off the amplifier in correspondence with the source. If the source unit
does not have a remote turn-on lead, then a power antenna wire can be used. If neither of these leads is
available at the source unit, then a switched +12V supply must be used, like the ACC, +12V.
Run a minimum of 18 gauge wire from the amplifier location to the source of the switched +12V lead. If pos-
sible, route this wire on the same side of the vehicle as your power cable. Connect the source remote output
to the wire. Go back to the amplifier and cut the wire to length. Loosen the screw terminal marked REM on
the amplifier. Insert the stripped (bare) portion of the wire into the terminal and tighten the screw securely.
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NOTE: It is highly recommended that a hand screw driver and NOT a power drill is used to
tighten the set screws on the terminal blocks. This will prevent stripping or other possible
damage to the amplifier.

RCA INTERCONNECT WIRING
Fig.4 Low Level Input using RCA
Choose the correct length and style of RCA interconnects for your needs. Always use high quality RCA audio
cables (not supplied) for signal connections—those with multiple layers of shielding or a twisted pair variety
provides better noise rejection.
Be extra careful when routing your RCA audio interconnect cables. Car environments are notorious for poorly
insulated wires. This means that hiss, engine noise, and fan noise can easily be picked up through RCA
cables if run incorrectly.
Make sure that the cables for power and audio signal are not on the same side of the vehicle and that they
do no cross each other; this will help reduce any noise that may radiate from the power cable and the signal
cable. If an audio cable is too close to a power cable, it may pick up the magnetic field generated by the
power cable, which could lead to a loss of quality in your signal.

TWO CHANNEL CONNECTIONS:
FLOATING GROUND RADIO (MOST COMMON TYPE)
TWO CHANNEL CONNECTIONS:
COMMON GROUND RADIO (RARE TYPE)
HIGH LEVEL CONNECTIONS (Optional)
High Level inputs have been included to connect the amplifier to a radio without low-level outputs (i.e. factory
radio). This connection will allow you to connect directly to the speaker output of the radio without the need
of an external adapter.
Determine the type of radio you have and make one of the following connections. Do not use the High Level
inputs if you have already wired the Low Level Inputs.
CAUTION! Before making any connections determine the type of radio to avoid possible damage to
amplifer and/or radio.
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This control allows you to match the input level of the amplifier to the output level of your head unit. Matching
the input can be accomplished in four simple steps:
1. Make sure that the remote gain control is not plugged in until after the master gain control is set.
2. Set the GAIN control on the amplifier to Min (completely counter clock wise).
3. Turn on the head unit and adjust volume to 2/3 maximum, and set the BASS and TREBLE to zero.
4. Adjust the LEVEL control clockwise until the sound just begins to distort, then back off slightly to cut
distortion and operate at optimum gain.
Remember, the level control is not a volume control. Ignoring these four steps above may leave you with
damaged speaker and/or a damaged amplifierr.
LPF (Low Pass Filter) Adjustment
The crossover frequency adjustment filters out frequencies that you don’t want your subwoofer(s) to repro-
duce. Using the LPF control, adjust the Low Pass Frequency to limit the amount of mid range you want going
to your subwoofer(s). Since musical tastes vary, adjust the crossover by ear while listening to the music of your
choice. Be sure to set the tone controls of your source unit to flat before adjusting the crossover
Sub Sonic Adjustment
The sub sonic control will filter out all frequencies below where the control it is set from going to your
subwoofer(s). This will prevent your subs from playing any low frequencies that may harm the speaker
SET UP ADJUSTMENTS
Input Gain Adjustment
Fig.5 Gain Control
Fig.7 Low Pass Control
Fig.6 Sub Sonic Adjustment

Remote Gain Controller Connection
Your PowerBass Autosound Class D amp includes a wired Remote Gain control module terminated with a
mini phone plug. To connect the Remote Gain Control to the amplifier, simply insert one the mini plug into the
REMOTE Gain jack. Install the module within easy reach on or under your dash.
0dB+18 dB
Fig.9 Control Module with Pre-wired Plug
Adjusting the BASS EQ and BASS FREQ Controls
The BASS EQ is adjustable from 0-18dB, thus allowing you to tailor your sound system to your particular tastes.
The BASS FREQ lets you choose the frequency that the BASS EQ will boost from 30Hz - 80Hz. You will want
to experiment with both controls—begin your adjustments at low volume. First turn the BASS EQ control about
half-way up. Next, vary the BASS FREQ control up and down. Adjust both controls until you find the right
combination that sounds best with the music you listen to most.
NOTE: More is not always better. By turning the BASS EQ all the way up to 18dB you can overwork
the amplifier and send the unit into thermal protection.
Fig.8a Bass EQ Control Fig.8b Bass FREQ Control
30Hz 80Hz
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SPEAKER WIRING AND CONFIGURATIONS
Speaker Load
Keep in mind your PowerBass Autosound Class D amp is a high power amplifier and not a high current ampli-
fier. In other words it requires a minimum impedance of 1 ohm. If you are unsure of calculating impedance
loads please consult your Authorized PowerBass Autosound Dealer before damaging your amplifier.
Too low of an impedance could send your amplifier into protection mode and/or damage the amplifier
Subwoofer Wiring
Choose the correct speaker wire for your application. We recommend a minimum of 16 gauge wire. Route
these using the same precautions as you did when you ran the power cable. Terminate these wires at the sub-
woofer end using insulated speaker terminals (not supplied) or by soldering the connection to the subwoofer.
Be certain to maintain correct polarity throughout the system. Make sure the subwoofer connections are
positive-to-positive and negative-to-negative. Most speaker wire has some indicator (color code, ribbing, or
printing) on one of the two wires to help you distinguish the positive (+) and negative (-) leads.
At the amplifier end, insert the stripped (bare) speaker wires into the properly marked terminals. Use a Phil-
lips screw driver to loosen the speaker terminals on the amplifier. Make certain that no bare wire ends touch
each other. Such contact could result in an electrical short and cause the amplifier to turn off (short circuit
protection) or malfunction.
NOTE: It is highly recommended that a hand screw driver and NOT a power drill is used to
tighten the set screws on the terminal blocks. This will prevent stripping or other possible
damage to the amplifier.

Fig.10 A Single Voice Coil Subwoofer (1~4 ohm)
Fig.11 Two 4 ohm Subwoofers with Single Voice Coil
Speaker Output Configurations
1. A SINGLE VOICE COIL SUBWOOFER SPEAKER
2. TWO SINGLE VOICE COIL SUBWOOFER SPEAKERS
(Note: Don’t connect speaker impedance under 1 ohm)
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3. ONE DUAL VOICE COIL SUBWOOFER SPEAKERS
(Note: Don’t connect speaker impedance under 1 ohm)
Fig.12 One Dual Voice Coil Subwoofer- Paralel Wiring
Fig.13 One Dual Voice Coil Subwoofer- Series Wiring
For additional wiring information visit our website www.powerbassusa.com
2-4 ohms DUAL VOICE COIL SUBWOOFER
Dual 4 ohm becomes 2 ohm as shown above
Dual 2 ohm becomes 1 ohm as shown above
1-4 ohms DUAL VOICE COIL SUBWOOFER
Dual 4 ohm becomes 8 ohm as shown above
Dual 2 ohm becomes 4 ohm as shown above
Dual 1 ohm becomes 2 ohm as shown above
CAUTION:
Maintaining proper impedance is critical when wiring the Class D model amplifiers. Improper wiring can cause
severe damage to BOTH the woofer and the amplifier. Detailed wiring diagrams are supplied with all PowerBass
woofers. IF YOU ARE NOT EXPERIENCED OR UNCOMFORTABLE READING THE WIRING DIAGRAMS CONSULT
YOUR AUTHORIZED POWERBASS DEALER BEFORE YOU ATTEMPT TO WIRE THE SYSTEM.

RECOMMENDED WIRE SIZES
Power Cable Selection Chart
Fuse Total 4Ft 4-7Ft 7-10Ft 10-13Ft 13-16 Ft 16-19 Ft 19-22 Ft
In Amperes Length of Wire/Gauge
150A - 200A 2 GA 2 GA 2 GA *1/0* *1/0* *1/0* *1/0*
125A - 150A 4 GA 4 GA 4 GA 4 GA 2 GA 2 GA 2 GA
105A - 125A 8 GA 8 GA 8 GA 4 GA 4 GA 4 GA 2 GA
85A - 105A 8 GA 8 GA 8 GA 4 GA 4 GA 4 GA 4 GA
65A - 85A 10 GA 8 GA 8 GA 8 GA 4 GA 4 GA 4 GA
PowerBass makes several types of amplifier wiring kits to assist with your installation. Consult your local
PowerBass dealer for details. For more information about recommended power wire check out our website at
www.powerbassusa.com.
PERSONAL NOTES:
Name: ______________________________________________________________
Date Purchased: ______________________________________________________
Dealer: _____________________________________________________________
Installed By: _________________________________________________________
Model: _____________________________________________________________
Serial Number: ______________________________________________________
Miscellaneous: ______________________________________________________
This manual is the exclusive property of PowerBass USA, Inc. Any reproduction of this manual, or use other than its intentions
is strictly prohibited without the express consent of PowerBass USA, Inc. © Copyright 2010 PowerBass USA, Inc.
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TROUBLESHOOTING TIPS
Problem Solution
Power LED not ON With a Volt Ohm Meter (VOM) check:
• +12 Volt power terminal (should read +12 to +16VDC
• Remote turn-on terminal (should read +12 to
+16VDC)
• Ground Terminal
Power LED lights BLUE, no output • Check RCA connections
• Test speaker outputs with known good speaker
• Substitute known good Source Unit
• Check for signal on the RCA cable with VOM in AC
position
Red Status Protection LED is ON, no
output and
1. Amp is VERY HOT
2. Amp shuts down ONLY when the
vehicle is running
3. Amp plays at very low volume
• Thermal protection is engaged. Check for proper
impedance at speaker terminals. Also check for
adequate air flow around the amplifier.
• Voltage protection engaged. Voltage to the amp is
not within the 10-16.5 VDC operating range. Have the
battery/charging system inspected.
• Short circuit protection is engaged.Check for speaker
wires shorted to each other or the vehicle chassis.
Speakers operating below the minimum impedance
can cause this to occur.
Alternator noise (varies with RPM) • Check for damaged RCA cable.
• Check routing of RCA cable
• Check Source Unit for good ground
• Check amp gain setting, turn down if set too high
• Check for chassis Ground short on speakers
Poor Bass Response Check speaker polarity, reverse the connection
of one speaker only.
NOTE: If the Status L.E.D. is activated and glows RED with no speakers connected to the amplifier,
and all the power connections are correct, this would indicate an internal problem with the ampli-
fier. Contact PowerBass USA or your local dealer.