Where this fits in the build
The subwoofer is only one part of the bass system. Enclosure volume and alignment, final impedance, amplifier power, vehicle space and electrical support all affect the result.
Description
PAC APSUB-CH42 AmpPRO SUB 2021+ Chrysler / Dodge / Jeep / RAM Subwoofer Integration
On the newer Chrysler-family premium systems, the customer can keep the factory radio and factory-powered cabin speakers and still add a real subwoofer system without turning the whole vehicle into a full amplifier-replacement job.
APSUB-CH42 is the focused bass-integration path for supported Chrysler, Dodge, Jeep and RAM applications using this newer architecture. It gives the aftermarket subwoofer amplifier a variable non-fading low-frequency signal while leaving the compatible factory premium-audio system in place.
That keeps the upgrade matched to the actual problem. If the customer only wants stronger low end, the full AP4-CH42 interface adds front and rear system capability the job may not need.
CH42 Fitment Includes Firmware and Factory-Audio Details
This family follows the newer Chrysler CAN/audio architecture, and PAC has continued adding support through firmware. PAC’s August 2026 guidance requires the specified firmware on supported 2021+ Grand Cherokee, 2022+ Wagoneer/Grand Wagoneer and 2025+ RAM applications.
Firmware is part of fitment, just like the vehicle and harness. Install the required firmware before installation.
Harman Kardon ANC Is a Special Case
PAC supplies an ANC-CH02 bypass harness with the APSUB-CH42, but PAC support guidance says that harness does not fit the Harman Kardon amplifier used in certain supported Grand Cherokee, Grand Wagoneer, Wagoneer and 2025+ RAM applications. On those vehicles, PAC directs the installer to leave the supplied ANC-CH02 unused and disconnect the 16-pin ANC connector at the Harman Kardon amplifier instead.
Confirm the factory amplifier before installation. Two vehicles that both fall under CH42 can need a different ANC handling method even though the AmpPRO SUB interface is the same part number.
Subwoofer Output, Not Full-Range Signal
APSUB-CH42 provides up to 5V RMS of variable subwoofer output and includes the remote level controller for bass adjustment after the system is set up. PAC also provides supported OE bass center-frequency adjustment so the new sub stage follows the factory-radio bass behavior more naturally.
If the build also needs aftermarket power or DSP on the front and rear speakers, AP4-CH42 is the correct full-system interface. APSUB-CH42 is intentionally limited to the low-frequency job.
Manufacturer Specifications
- Model: APSUB-CH42
- Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
- Application: Select newer Chrysler, Dodge, Jeep and RAM vehicles with compatible premium factory audio
- Purpose: Add an aftermarket subwoofer amplifier while retaining the supported factory radio/audio system
- Output: Variable non-fading subwoofer preamp output
- Maximum output: 5V RMS
- Frequency use: Low-frequency/subwoofer output only; not a full-range AP4 replacement
- Adjustment: Customizable supported OE bass center frequency
- Firmware: Required firmware applies to specified newer CAN applications
- ANC: ANC-CH02 bypass harness supplied; PAC procedure differs on specified Harman Kardon applications
- Sub-level control: Included remote controller
Manufacturer: PAC