PAC AmpPRO SUB — Choose the Correct Factory Audio Interface
One listing, six original PAC AmpPRO SUB models. Choose the exact Vehicle and factory audio model to add a dedicated subwoofer amplifier signal while retaining compatible factory radio and cabin-speaker operation. AmpPRO SUB is a bass-integration solution; for full-range external amplifier or DSP integration, consider the separate PAC AmpPRO 4 family.
Match the bike or vehicle: confirm year, model, factory premium audio, GM IO5/IO6 if applicable, JBL/Sony/B&O system, included harnesses, ANC handling and required firmware before ordering. A Jeep, Ford, GM or Toyota badge alone does not verify compatibility. Every option is a different physical SKU with its own original configured price; selecting one does not include other modules.
Ask SMS Car Audio to verify the vehicle audio architecture before installation or quote.
Chrysler, Dodge, Jeep and RAM — 3 interface options
APSUB-CH21 — Chrysler, Dodge, Jeep & RAM Subwoofer Integration — APSUB-CH21
Original configured retail price: $329.00
If the factory system already does what the customer wants everywhere except the low end, there is no reason to rebuild the whole audio system just to add real bass.
APSUB-CH21 is PAC’s focused subwoofer-integration interface for supported older Chrysler-family factory-amplified systems. It keeps the factory radio and compatible factory amplifier in place, then gives the aftermarket subwoofer amplifier a controlled non-fading low-frequency signal instead of making us grab a random speaker wire and hope the factory processing behaves.
That is the right kind of solution when the customer wants stronger, cleaner bass but is not asking us to move the front and rear speakers onto new amplification.
APSUB vs. the Full AP4-CH21
The difference is scope. AP4-CH21 gives us front, rear and non-fading/subwoofer signal for a full amplifier or DSP upgrade. APSUB-CH21 is deliberately narrower: its output is for the subwoofer system only.
That keeps the parts list and installation focused when the factory cabin speakers are staying exactly where they are. If the build grows into a full speaker-amplifier or DSP system, the full AmpPRO interface makes more sense than trying to stretch a sub-only product into a job it was never designed to do.
How the Bass Stage Fits the Factory System
The variable output can feed the aftermarket subwoofer amplifier directly, and the included level controller gives the customer an easy way to trim bass level after the system is set up. PAC also allows the supported OE bass center frequency to be adjusted through the interface so the new sub stage works with the factory-radio behavior instead of fighting it.
The vehicle still has to match PAC’s exact application. Wrangler JK, Grand Cherokee, Grand Caravan, Challenger, RAM and other Chrysler-family platforms appear in supported coverage, but the year, radio and factory audio package decide fitment.
Manufacturer Specifications
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Model: APSUB-CH21
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Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
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Application: Select Chrysler, Dodge, Jeep and RAM vehicles with compatible factory-amplified audio
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Purpose: Add an aftermarket subwoofer amplifier while retaining the factory radio and supported factory audio system
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Output: Variable non-fading subwoofer preamp output
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Maximum output: 5V RMS
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Frequency use: Low-frequency/subwoofer output only; not a full-range AP4 replacement
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Adjustment: Customizable supported OE bass center frequency
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Installation: Vehicle-specific plug-and-play connection
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Sub-level control: Included remote controller
Included
- APSUB-CH21 interface
- Vehicle-specific harness
- Flush-mount sub-level controller
- Manufacturer documentation
Manufacturer: PAC
APSUB-CH41 — Chrysler, Dodge, Jeep & RAM Subwoofer Integration — APSUB-CH41
Original configured retail price: $329.00
On the supported Chrysler-family systems with Active Noise Cancellation, adding a subwoofer is two jobs: get a clean bass signal and keep the factory ANC from trying to cancel the bass we just added.
APSUB-CH41 handles both. It provides a controlled non-fading low-frequency output for the aftermarket subwoofer amplifier and includes the ANC bypass harness PAC specifies for the supported applications.
That makes it the focused answer when the customer likes the factory radio and cabin-speaker system but wants more low end. We can solve the bass problem without buying a full-system AP4 interface the rest of the system does not need.
Why the ANC Bypass Is Part of the System
Factory ANC uses cabin microphones and the audio system to create low-frequency correction. Once a stronger aftermarket subwoofer enters the vehicle, that correction can work against the new bass stage and create strange output, cancellation or unwanted low-frequency behavior.
PAC includes the bypass harness so the supported ANC system is addressed as part of the install instead of leaving it active and hoping it does not interfere.
Subwoofer Integration Only
APSUB-CH41 provides a variable subwoofer output up to 5V RMS. It is not a full-range front/rear signal source. If the build is also moving the cabin speakers onto aftermarket amplification or adding a full DSP system, AP4-CH41 is the more appropriate interface.
The included level controller gives the customer easy bass-level adjustment after tuning, and PAC allows the supported OE bass center frequency to be customized so the new subwoofer stage works more naturally with the factory-radio controls.
Manufacturer Specifications
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Model: APSUB-CH41
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Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
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Application: Select Chrysler, Dodge, Jeep and RAM vehicles with compatible factory-amplified audio
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Purpose: Add an aftermarket subwoofer amplifier while retaining the supported factory radio/audio system
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Output: Variable non-fading subwoofer preamp output
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Maximum output: 5V RMS
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Frequency use: Low-frequency/subwoofer output only; not a full-range AP4 replacement
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Adjustment: Customizable supported OE bass center frequency
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ANC: ANC bypass harness included
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Sub-level control: Included remote controller
Included
- APSUB-CH41 interface
- Vehicle-specific harness
- ANC bypass harness
- Flush-mount sub-level controller
- Manufacturer documentation
Manufacturer: PAC
APSUB-CH42 — 2021+ Chrysler, Dodge, Jeep & RAM Subwoofer Integration — APSUB-CH42
Original configured retail price: $329.00
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
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Model: APSUB-CH42
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Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
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Application: Select newer Chrysler, Dodge, Jeep and RAM vehicles with compatible premium factory audio
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Purpose: Add an aftermarket subwoofer amplifier while retaining the supported factory radio/audio system
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Output: Variable non-fading subwoofer preamp output
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Maximum output: 5V RMS
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Frequency use: Low-frequency/subwoofer output only; not a full-range AP4 replacement
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Adjustment: Customizable supported OE bass center frequency
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Firmware: Required firmware applies to specified newer CAN applications
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ANC: ANC-CH02 bypass harness supplied; PAC procedure differs on specified Harman Kardon applications
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Sub-level control: Included remote controller
Manufacturer: PAC
Ford — 1 interface option
APSUB-FD21 — Ford Factory-Amplified Subwoofer Integration — APSUB-FD21
Original configured retail price: $329.00
If the Ford system only falls short in the low end, we do not need to turn a subwoofer upgrade into a full front/rear amplifier replacement.
APSUB-FD21 gives the aftermarket subwoofer amplifier a controlled non-fading low-frequency signal while keeping the supported factory radio and factory-amplified cabin-speaker system in place. That is the clean answer when the customer likes the rest of the system and simply wants more authority below it.
The Factory Audio Package Still Decides Fitment
Many supported applications use Ford’s Sony system, but PAC’s coverage is more specific than the badge suggests. Certain 2018–2019 Super Duty applications can use supported Sony or B&O systems, while supported 2019+ Mustang applications require the compatible B&O system.
An amplified Ford with an unbadged analog amplifier is not automatically an APSUB-FD21 vehicle. Confirm the actual factory amplifier and audio architecture before ordering instead of assuming any powered Ford system belongs on this interface.
Why the SUB Version Makes Sense
APSUB-FD21 provides variable low-frequency output up to 5V RMS and includes the remote level controller for bass adjustment after the system is tuned. PAC also allows supported OE bass center-frequency selection so the new sub stage follows the factory-radio bass behavior more naturally.
The important limitation is also the reason to buy it: the output is subwoofer-only. If the build needs full-range signal for front/rear amplification or DSP, AP4-FD21 is the correct full-system interface instead.
Manufacturer Specifications
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Model: APSUB-FD21
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Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
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Application: Select Ford vehicles with compatible data-bus-controlled factory-amplified audio
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Purpose: Add an aftermarket subwoofer amplifier while retaining the supported factory radio/audio system
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Output: Variable non-fading subwoofer preamp output
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Maximum output: 5V RMS
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Frequency use: Low-frequency/subwoofer output only; not a full-range AP4 replacement
-
Adjustment: Customizable supported OE bass center-frequency selection
-
Installation: Vehicle-specific plug-and-play connection
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Sub-level control: Included remote controller
Included
- APSUB-FD21 interface
- Vehicle-specific harness
- Flush-mount sub-level controller
- Manufacturer documentation
Manufacturer: PAC
General Motors — 1 interface option
APSUB-GM61 — GM IO5 & IO6 Subwoofer Integration — APSUB-GM61
Original configured retail price: $379.00
If the GM factory system is fine everywhere except the low end, the clean answer is to add bass without rebuilding the rest of the audio system.
APSUB-GM61 gives the aftermarket subwoofer amplifier a controlled two-channel, non-fading low-frequency signal while keeping the compatible factory radio and supported vehicle audio functions in place. APSUB-GM61 requires a supported IO5 or IO6 infotainment system. Compatible applications can be equipped with or without Bose.
That makes this a much better starting point than grabbing a random factory speaker wire and hoping the factory EQ, volume behavior and vehicle data do not change what reaches the new subwoofer amplifier.
Verify the IO RPO Code Before Ordering
The Bose badge can help identify a system, but it is not the fitment rule for APSUB-GM61. The vehicle must have IO5 or IO6. The vehicle and infotainment RPO code must match before ordering instead of treating every 2014–2019 GM radio architecture as interchangeable.
If the vehicle has a factory amplifier, that amplifier remains installed and connected after APSUB-GM61 is added. The interface works with the factory system rather than turning a bass-only upgrade into a full amplifier-replacement job.
ANC Is Part of the Bass Problem on Equipped Vehicles
GM Active Noise Cancellation can react to stronger aftermarket bass and work against the new subwoofer. PAC includes the ANC-GM03 bypass harness so ANC can be disabled correctly on equipped applications instead of leaving the microphones and cancellation system to fight the bass after the install.
What the Subwoofer Amplifier Actually Gets
APSUB-GM61 uses the factory full-range fixed-level source plus vehicle data to create a variable 5V RMS preamp output with bass EQ and level control. PAC applies a 350 Hz, 24 dB-per-octave Linkwitz-Riley low-pass filter to the output and provides a data-controlled remote turn-on rated at 2 amps.
The included level controller gives the customer bass adjustment after the system is set up. The output remains subwoofer-focused; if the build needs front, rear or full DSP signal for the cabin speakers, the full AP4 integration path is the better starting point.
Manufacturer Specifications
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Model: APSUB-GM61
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Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
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Application requirement: Select 2014–2019 GM vehicles with compatible IO5 or IO6 infotainment systems
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Factory audio: Supported applications may be equipped with or without Bose
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Output: Two-channel non-fading subwoofer preamp output
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Maximum output: 5V RMS
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Low-pass filter: 350 Hz / 24 dB-per-octave Linkwitz-Riley
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Remote turn-on: Data-controlled output, 2A maximum
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Factory amplifier: If originally equipped, it remains installed and connected
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Supported retained audio: OnStar, Bluetooth, navigation, safety-system audio and warning chimes
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ANC: ANC-GM03 bypass harness included for equipped applications
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Sub-level control: Included flush-mount controller
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Output limitations: Factory speed-controlled volume and surround mode are not supported through the APSUB-GM61 subwoofer outputs
Included
- APSUB-GM61 amplifier integration adapter
- Vehicle-specific harness
- ANC-GM03 bypass harness
- Flush-mount sub-level controller
Manufacturer: PAC
Toyota and Lexus — 1 interface option
APSUB-TY13 — Toyota & Lexus JBL Subwoofer Integration — APSUB-TY13
Original configured retail price: $329.00
If the supported Toyota or Lexus premium system already does what the customer wants through the cabin and only needs more low end, keep the upgrade focused on the subwoofer.
APSUB-TY13 gives the aftermarket subwoofer amplifier a controlled non-fading low-frequency signal while keeping the compatible factory radio and premium-audio system in place. That avoids building the bass system from a random factory speaker channel that has already been shaped by the stock amplifier.
Why the SUB Version Is the Right Size for the Job
The full AP4-TY13 interface gives us front, rear and non-fading/subwoofer signal for a complete amplifier or DSP upgrade. APSUB-TY13 is intentionally narrower. It is for the customer who wants the bass stage upgraded while the factory cabin-speaker system stays where it is.
That keeps the parts list and installation matched to the actual goal instead of buying full-system integration capability the build will not use.
How It Works With the Factory System
APSUB-TY13 provides variable subwoofer output up to 5V RMS and includes the flush-mount controller for bass-level adjustment after tuning. PAC also provides supported OE bass center-frequency selection so the new sub stage follows the factory-radio bass behavior more naturally.
The vehicle-specific harness keeps the installation plug-in and serviceable on supported applications. The output is low-frequency/subwoofer only. If the plan grows into aftermarket front/rear amplification or DSP, AP4-TY13 becomes the correct starting point.
Fitment is still application-specific. PAC validates exact Toyota and Lexus year/model/factory-audio combinations rather than treating every 2018+ JBL vehicle as interchangeable.
Manufacturer Specifications
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Model: APSUB-TY13
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Product type: PAC AmpPRO SUB subwoofer amplifier integration interface
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Application: Select 2018+ Toyota and Lexus vehicles with compatible premium factory-amplified audio
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Purpose: Add an aftermarket subwoofer amplifier while retaining the supported factory radio/audio system
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Output: Variable non-fading subwoofer preamp output
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Maximum output: 5V RMS
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Frequency use: Low-frequency/subwoofer output only; not a full-range AP4 replacement
-
Adjustment: Customizable supported OE bass center-frequency selection
-
Installation: Vehicle-specific plug-and-play connection
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Sub-level control: Included remote controller
Included
- APSUB-TY13 interface
- Vehicle-specific harness
- Flush-mount sub-level controller
- Manufacturer documentation
Manufacturer: PAC
