APSUB-CH42 - Car audio amplifier PAC - Free user manual and instructions

Product Type	Advanced Subwoofer Amplifier Interface
Brand	PAC
Model	APSUB-CH42
Compatible Vehicles	Select Chrysler, Dodge, Jeep, RAM vehicles with data-bus controlled amplified sound system (Alpine or Harmon Kardon)
Output Channels	2-channel non-fading pre-amp output
Output Voltage	5V RMS (adjustable to 4V RMS via DIP switch 2)
Low Pass Filter	350Hz, 24dB/octave Linkwitz-Riley
Remote Turn-On Output	2A max
Included Accessories	Level control knob, ANC-CH02 harness, harness cables
DIP Switch Settings	Switch 2: lowers output to 4V (ON); others not used
Minimum Volume Adjustment	Via programming button, steering wheel controls, or AmpPRO PC app
Active Noise Cancellation Bypass	Yes, using included ANC-CH02 harness
PC App Support	AmpPRO PC app for configuration and firmware updates
Power Supply	12V DC from vehicle electrical system
Dimensions (Approx.)	4.5 x 3.5 x 1.2 inches (114 x 89 x 30 mm)
Weight (Approx.)	0.3 kg (0.66 lbs)
Mounting Type	Inline harness connection, module can be tucked behind radio
Warranty	1 year limited (contact PAC for details)
Material	Plastic casing with metal shielding
LED Indicators	LED 1: solid red (active), amber (min volume mode); LED 2: blinking amber (USB detected)

Frequently Asked Questions - APSUB-CH42 PAC

What vehicles is the APSUB-CH42 compatible with?

The APSUB-CH42 is designed for select Chrysler, Dodge, Jeep, and RAM vehicles that have a data-bus controlled amplified sound system. Look for an Alpine or Harmon Kardon badge on the door speakers, center speaker, or factory subwoofer to confirm compatibility.

How do I adjust the output voltage of the APSUB-CH42?

You can lower the RCA output voltage from 5V to 4V by setting DIP switch 2 to the ON (down) position. Leave it OFF (up) for 5V output.

How do I set the minimum volume level?

To adjust the minimum volume, first turn the level control knob fully counter-clockwise. Set the factory radio volume to 1. Then either press the programming button on the module or press and hold the track down button on the steering wheel for 10 seconds until LED 1 turns amber. Turn the level control knob clockwise to set the desired level, then wait 10 seconds to exit.

What is the purpose of the level control knob?

The level control knob allows you to manually adjust the subwoofer output level. It must be connected to set the minimum volume; if disconnected, the output defaults to 100%.

How do I bypass Active Noise Cancellation (ANC)?

Use the included ANC-CH02 harness. Access the factory amplifier, disconnect its 10-pin harness, plug the ANC-CH02 into the amplifier, then connect the factory harness to the ANC-CH02. This disables the ANC system to prevent interference with the subwoofer.

Can I use the AmpPRO PC app with the APSUB-CH42?

Yes, the AmpPRO PC app allows you to configure user interface options like minimum volume level, enable/disable factory EQ, set bass center frequency and Q factor, update firmware, and read hardware/software versions. Download it from PAC-Audio.com.

How do I reset the APSUB-CH42 module?

To reset, turn the ignition to the ON position, then press and hold the Volume Down button on the factory steering wheel controls for 12 seconds until you hear a tone. Alternatively, press and hold the programming button on the side of the module for 10 seconds until the LEDs alternate flashing red.

What do the LED indicators mean on the APSUB-CH42?

LED 1: solid red indicates module active, solid amber means minimum volume adjustment mode. LED 2: blinking amber indicates a USB connection is detected. Both LEDs alternating red indicates a memory reset is in progress.

How do I update the firmware of the APSUB-CH42?

Connect the module to your PC, open the AmpPRO PC app, select 'Firmware' then 'Update Firmware', choose 'Select File', browse to the firmware file from PAC-Audio.com, and press update. Once finished, disconnect the module.

What should I do if the low volume setting on the radio is too loud?

Set the minimum volume level using the programming button, steering wheel controls, or the AmpPRO PC app. Follow the setup and configuration instructions in the manual to lower the minimum volume to your preference.

USER MANUAL APSUB-CH42 PAC

Introduction and Features

The APSUB-CH42 provides a 2-channel non-fading pre-amp output for use with an aftermarket amplifier and subwoofer. Using the full range, fixed level head unit output, in conjunction with CAN messages, the APSUB-CH42 delivers a low pass variable 5v RMS pre-amp output with bass equalization and level control capabilities. The signal has a 350Hz / 24dB Linkwitz-Riley low pass filter applied. A data controlled remote amplifier turn on wire is also provided by the APSUB-CH42.

Important Notes

1. This interface is only compatible in vehicles equipped with a data-bus controlled amplified sound system. To verify compatibility, look for an Alpine or Harmon Kardon badge on the door speakers, center speaker, or factory subwoofer. If none of these brands are shown; check for the presence of a center speaker or subwoofer.
2. The factory amplifier must remain connected, and in the vehicle after the APSUB-CH42 has been installed.
3. The remote output is rated at 2A of current. If more current is needed an external relay must be used.
4. The subwoofer outputs are non-fading. The output level of the subwoofer channel can be controlled using the supplied level control knob. If the level control knob is not connected the output level will default to 100%.
5. The minimum volume level is set to a default. If you are happy with this level in your particular application then additional adjustment is not required. Please refer to the Setup and Configuration section on page 2 for more details.
6. The level control knob must be connected in order to manually adjust the minimum volume setting.
7. No adjustments can be made manually using the programming button or the factory SWC when the module is connected to a PC.
8. If the vehicle is equipped with Active Noise Cancellation (ANC), the ANC can be disabled using the included ANC-CH02 harness. See page 3.

The aftermarket amplifier must have a very solid ground and the amplifier power/ground connections should be made before connecting the RCA's or Remote Turn On to the APSUB-CH42

Wiring Connection Chart

graph TD
    A["APSUB-CH42-HAR"] --> B["To Radio"]
    A --> C["To Vehicle Harness"]
    D["Subwoofer Outputs"] --> E["Non-Fading Level Control Knob"]
    D --> F["To Aftermarket Amplifier"]
    G["Remote Turn On Output 2A Max Output"] --> A
    H["To Factory Amplifier"] --> I["ANC-CH02-HAR"]
    J["To Amplifier Harness"] --> I
    style A fill:#f9f,stroke:#333
    style D fill:#ccf,stroke:#333
    style G fill:#cfc,stroke:#333

APSUB-CH42

Advanced Subwoofer Amplifier Interface for Select Chrysler / Dodge / Jeep / RAM Vehicles

Module Layout

Installation

Set DIP switches to the ON position to activate the corresponding features. Set DIP switches to the OFF position for any features that are not desired.

No Function 5v /	4v Preout No Function No Function
1 2 3 4

1. Remove factory radio.
2. Disconnect the main 32 & 12-pin factory harness connector from radio.
3. Connect APSUB harness to vehicle harness.
4. Connect APSUB harness to factory radio.
5. Set any feature DIP switches that apply to your install.

a. Set DIP switch 2 on (down) to lower the RCA output voltage to 4v. Leave DIP switch 2 off (up) to keep the RCA output voltage at 5v.

b. DIP switches 1, 3, and 4 are not used.

1. Connect the APSUB harness to the module.
2. Connect the level control knob to the module and install in an accessible location.
3. After the aftermarket amplifier power/ground connections are made, connect the signal cables and remote input from the aftermarket amplifier to the APSUB.
4. Reconnect any additional harnesses removed from the radio and reinstall the radio.

Setup and Configuration

1. Turn the ignition on. LED 1 on the interface will turn on and the +12v remote output will turn on.
2. Set the amp gain(s) to the desired level. We recommend using an oscilloscope and test tones to set the amp gain(s). Please refer to the MECP Advanced study guide (p. 360) if you are unfamiliar with this process.
3. Check volume, balance, fade and EQ settings.
4. If you would like to adjust the minimum volume, do so using one of the methods outlined on the next page. If you are happy with the default levels, no adjustments are necessary.

Manually Setting the Minimum Volume (optional)

If the minimum volume of the radio (factory radio volume level 1) is too loud or too quiet, you can manually set the level of the minimum volume using either the programming button on the side of the interface or the radio dash panel controls. If you would like to set the minimum volume using the AmpPRO PC app, please proceed to the AmpPRO PC app section.

Setup and Configuration (cont.)

PLEASE NOTE: Level control knob must be connected to module for either of the following methods

Setting the minimum volume using the programming button

1. Start with the level control knob turned all the way down (counter-clockwise).
2. Set the amp gains to the desired level.
3. Set the volume on the factory radio to 1.
4. Press the programming button on the side of the interface once.
5. LED 1 will turn amber and the chimes will begin sounding every five seconds.
6. Turn the level control knob clockwise until the desired minimum volume level is reached.
7. You can now either press the programming button once or wait ten seconds to exit the settings.

Setting the minimum volume using the factory dash panel controls

1. Start with the level control knob turned all the way down (counter-clockwise).
2. Set the amp gains to the desired level.
3. Set the volume on the factory radio to 1.
4. Press and hold the track down button on the factory SWC (Back left of steering wheel) for approximately ten seconds. PLEASE NOTE: The radio will respond to the SWC commands during this process, this is normal and has no effect on the APSUB operation.
5. LED 1 will turn amber and the chimes will begin sounding every five seconds.
6. Turn the level control knob clockwise until the desired minimum volume level is reached.
7. You can now wait ten seconds to exit the settings.

Active Noise Cancellation (ANC) Bypass

When adding a subwoofer to a vehicle equipped with ANC, the ANC system will attempt to cancel out the bass frequencies being generated by the aftermarket subwoofer. This results in unwanted "noise" being produced by the factory speakers.

Identifying ANC in the Vehicle

Vehicles with multiple microphones located in the door panels or headliner locations will usually be equipped with ANC. If you are unsure, the ANC-CH02 can be installed with no negative effect on vehicles not equipped with ANC.

Bypassing the ANC Signal

1. Access the factory amplifier (see location info to the right).
2. Disconnect the 10-pin factory harness from the amplifier.
3. Plug in the ANC-CH02 harness into the amplifier.
4. Connect the 10-pin factory harness to the ANC-CH02.

Vehicle	Amplifier Location
Jeep GladiatorJeep Wrangler JLRAM Truck 2500+	Driver Side of Dash
RAM Truck 1500	Under Driver Seat
Chrysler PacificaJeep Cherokee	Passenger Side of Dash
Dodge Durango*Jeep Grand Cherokee*	Driver Side Rear Quarter Panel

Note: Some models are not included in this table because ANC is not an available option for those vehicles.
Common Trim locations listed: Some trims may be located elsewhere in vehicle.

TO AMPLIFIER TO AMPLIFIER HARNESS

Pure diagram of a twisted cable or wire structure without any text, numbers, or symbols

*On some Grand Cherokee and Durango models, the vehicle may be equipped with a factory amplifier and a separate ANC module and the ANC-CH02 will not fit into any connector on the amplifier. In which case, the ANC-CH01 harness (sold separately) would need to be installed at the ANC module behind the Passenger Side Rear Quarter Panel to deactivate the ANC system.

AmpPRO PC App

Use of the AmpPRO PC App allows you to do the following:

- Configure User Interface Options such as:

• Minimum Volume Level
- Enable / Disable Factory EQ
- Set Bass Center Frequencies and Q Factor

• Update Product Firmware
• Read Firmware / Hardware Versions
• You can download the AmpPRO app at :

https://pac-audio.com/app-downloads/

PLEASE NOTE: These settings can be adjusted with the module installed in the vehicle, or on the bench. However, it is recommended to make the adjustments with the module installed, and the factory radio on, so that the changes can be heard.

Minimum Volume Level - This allows you to set the minimum volume level of the factory radio (factory radio volume level 1).

EQ Enabled - This allows you to enable / disable the bass band factory EQ from adjusting the APSUB output.

Bass Freq / Q Factor - This allows you to set the center frequency that will be adjusted when setting the bass band on the factory EQ, as well as the Q Factor for the frequency. The Q Factor determines how many of the adjacent frequencies will be affected when adjusting the selected frequency. The lower the Q Factor, the more frequencies will be affected. See below for available frequencies and Q Factors. Note: This setting only affects the output of the APSUB and does not change the way that the factory EQ adjusts the factory speakers.

Bass Frequency	60HZ
	80HZ
	100HZ
	120HZ
Bass Q Factor	0.50
	1.00
	1.50
	2.00

F1: 60Hz Center Frequency | 0.50 Q Factor
F2: 100Hz Center Frequency | 2.00 Q Factor

Firmware Updates

The AmpPRO PC app will also allow you to update the interface with new firmware as it becomes available. Please visit www.pac-audio.com or contact our tech support department to see if there is a firmware update for your interface.

AmpPRO PC App (cont.)

Firmware Updates (cont.)

To view Product Software and Hardware Version, connect the interface to your PC and select "About".

To update the firmware, connect the interface to your PC and select "Firmware", then "Update Firmware". Now select "Select File". Finally, browse to the place where you saved the file and select it. This will begin the updating process. Once finished, disconnect the interface from the PC and resume normal operation.

Restoring Factory Settings

You can restore the interface to factory default settings by pressing and holding the programming button on the side of the module for 10 seconds until the status LEDs start blinking red. Once the LEDs start blinking red, release the button.

This reset will restore the following settings to their factory defaults:

• Minimum Volume Level
- Enable / Disable Factory EQ
• Factory EQ Frequency
• Factory EQ Q Factor

Troubleshooting

1. Low volume setting on radio is too loud - Set the minimum volume using process outlined in Setup and Configuration, or using the AmpPRO PC app.
2. If for any reason the APSUB module becomes unresponsive, or will not power up with the key on, you can reset the interface by turning the key to the ignition position, then pressing and holding the Volume Down button on the factory steering wheel controls for 12 seconds until a tone is heard, or by pressing and holding the reset button on the side of the APSUB module for 10 seconds (until the LEDs alternate flashing red).

LED Legend
LED 1	Action/Color During	Normal Operation
	Solid Red Module Active
	Solid Amber Minimum Volume	me Adjustment Mode
	Rapid Blink Any Color DSP	Activity
LED 2 Blinking Amber USB Connection		Detected
Both LEDs	Alternate Blinking Red Performing Memory Reset

Technical Support

Email: [e-mail]

Phone: [phone]

Chat: PAC-Audio.com