Ford ACM Channels

Ford ACM Channels and Zen 

In Fords, ACM stands for Audio Control Module - that means “head unit” to those of us in aftermarket audio. In base audio sound packages, the ACM “deck power” amplifies the front and rear speakers with around 25 watts each.(In pre-2025 models, the ACM used a BTL Class B IC; in 2025+, the IC is usually a Class D amplifier with 25W RMS). 

 

ACM in base audio packages

 

In vehicles with the upgraded Bang and Olufsen sound packages, the ACM supplies the left and right audio signals to the B&O DSP amplifier via the A2B network. The DSP chip in the B&O amplifier splits up the signals into front high, front low, rear, sub, center upmixed, height upmixed, etc. 

In the diagram below, some of these channels are processed and amplified in the B&O amp, but some channels are only processed in the amp, travel back up the A2B network into the ACM head unit, and then are amplified in the ACM.

In different sound packages and in different model years, these ACM amplified outputs power different speakers. In this article, we will focus on the F-150 as an example. 

ACM Channels and A2B

 

In F-150 B&O 8-speaker systems, two ACM channels power the front tweeters, and no other ACM channels are used. All other speakers are powered by the B&O amplifier. 

However, new wires can readily be run to the A-pillars from the ZENPower9 if desired, allowing 70 watts to power each tweeter.

 

Ford F-150 B&O 8-speaker system

 

In B&O Unleashed systems before 2024, two ACM channels power the tweeters, and two ACM channels power the rear door speakers (everything else, including the headliner speakers, is powered by the B&O amplifier).

 

Ford F-150 B&O Unleashed, pre-2024 (headrest speakers not shown)

 

In these pre-2024 B&O Unleashed vehicles, we recommend retaining ACM power for the front tweeters, as the ZENPower9’s 70W channels are used to power the dash midranges. 

In these pre-2024 B&O Unleashed vehicles, the ACM is also used to power the rear door speakers - the headliner speakers (if retained) are powered by the B&O amplifier, and thus by the ZENPower9. If desired, these can be reversed, but additional wiring is required. 

NOTE: The transition discussed here, pre-2024 and 2024+ speaker assignments, is a different change from the A2B 1.0/A2B 1.1 network change that occurred in 2025 model year F-150 trucks. 

In B&O Unleashed systems in 2024 and newer models, the front ACM channels power the tweeters, the rear ACM channels power the headliner speakers, and the B&O amplifier powers everything else (including the rear door speakers).

 

Ford F-150 B&O Unleashed 2024+

 

 

Here’s a table for easy reference:

These ACM output channels have not been available to the aftermarket system designer for use - but ZEN solves this problem in F25 and A2B+ preamps and ZENPower9 amplifiers! 

In addition to the six channels made available by the ZEN preamp, the system designer can now use the four ACM channels with a ZEN preamp or amplifier. Both process the ACM channels with the internal ZEN DSP. 

 

ACM with a Zen A2B+ or F25 preamp

 

 

ACM with a Zen POWER9 amplifier

 

In practice, tweeters do not require much power, and the ACM outputs are very clean and free of distortion - using them delivers much cleaner power than you might expect. 

In the Zen POWER9 A2B amplifiers and the Zen A2B+ and F25 preamps, the following DSP controls for the ACM channels are provided:

    • Equalization
    • Delay
    • Level
    • Crossover Filtering
    • Polarity and Phase

This allows the skilled user to tune cabin speakers managed by an external DSP and the ACM-powered speakers managed by the ZEN - together!

If the ACM channels are not used in the system, they can be defeated in the DSP preamp settings. 

NOTE: In Fords other than the F-150, ACM channels are used in other ways. In the Ford Ranger and Bronco with B&O, for example, the center speaker and the front tweeters are powered by the ACM - all other speakers are powered by the B&O DSP amplifier. 

To power the tweeters with the Zen POWER9, wires must be run. These wires are included in the optional Ranger and Bronco install kits.