Ford Sync 4A after market amplifiers

I just came across this forum and wondered if anyone might be able to shed any light on a problem that I have.

There are various Ford models running Sync 3, 4 or 4A that were/are available with the B&O sound system that adds an external B&O DSP and Amp to the vehicle as well as a different speaker setup. For these models there are a couple of different after market modules available that replaces the B&O module and allows you to connect to conventional after market amplifiers so you can create your own more powerful setup.

e.g. Audio Interface - ZEN-A2B / DSP6A-A2B - NAV-TV

The problem I face is that due to the ongoing global supply chain issues, the Ford model that I wish to order is not currently available with the B&O module and instead I would have to make do with the standard speaker setup. The problem is that the manufacturers of these modules clearly state that they only work with models that come with the B&O module. When I contacted the manufacturers they were very vague as to the reasons, simply saying it would not work with a non-B&O system.


  • models with or without the B&O setup come with a Sync 4A head unit

  • if the vehicle came with the B&O setup my first step to upgrading the audio would be to take all of the B&O setup out of the vehicle

  • but if the vehicle comes from the factory without the B&O setup, I can’t seem to find a way to upgrade the audio setup as there does not appear to be a way of getting a non-amplified audio feed out of the Sync 4A head unit

I wondered if anyone had any thoughts on this? For example, is there a way of getting the Sync 4A head unit to think the B&O system is installed so the A2B output interface becomes active? Or is there some breakout from the APIM connector that I could use?

Many thanks,


New models can come with Sync 3, 4, or 4A depending on the trim level, and with or without the B&O system. Yes, this is true, so there are options…

if the vehicle came with the B&O setup my first step to upgrading the audio would be to take all of the B&O setup out of the vehicle…

In that case you would be left with a model without the B&O system, which would need some work with the APIM and ACM asbuilts to get the alert and NAV tones/sounds, etc., to work properly. There are adapters for this purpose. If you have not listened to the B&O system in the specific vehicle you are considering, you should do this first to identify what you think the short comings of the system, rather than listening to a group of “audiophiles” on the internet. This way you can make your own real-world judgement on where to spend your money and what will be most effective in that environment.

Audio is subjective and listening to any audio in a new environment will certainly be different than what the user will think is “normal”. Most of the complaints about the system are just plain inexperience on the part of the user, thinking that more power or extreme eq settings will magically fix what they think they are hearing. Of course, most of the audio equipment manufacturers contribute to this issue greatly.

but if the vehicle comes from the factory without the B&O setup, I can’t seem to find a way to upgrade the audio setup as there does not appear to be a way of getting a non-amplified audio feed out of the Sync 4A head unit

Sound comes from the ACM, not the APIM, to feed the sound system. Although the USB ports and phone sounds are originated in the APIM, they go directly to the ACM for processing and routing. This is your demarc point to feed the new system.

The ACM for Sync 4/4A vehicles does not appear to have a line level output option in the asbuilt. However, this can be solved by replacing the ACM with one that does, like an MT4T model ACM. As far as A2B, you can just use the discrete outputs if you like.

Thanks for the feedback and information F150Chief.

I currently have a 2014 Ford Ranger crew cab and I am looking to update to a brand new Ford Ranger crew cab. Back in 2014 I did a major audio overhaul on the Ranger with custom A pillar speaker mounts for separate tweeters and mids and I managing to squeeze a correctly sized sub box of my own design and construction in behind the rear seats with a pair of low profile 10" drivers in it. It is a very sweet sounding setup!

If the B&O system were available it is possible from what I have heard that I would be happy with it, although I suspect the single 5" sub the system comes with would likely leave me wanting more. However, as my only option right now is the standard (non-B&O) 8 speaker system I am pretty certain this is not going to be good enough for me, to the point where if I cannot find a solution to this I would simply not place an order for a new Ranger.

The new Ranger is listed as coming with Sync 4A regardless of the B&O option or not. I only ever use Apple CarPlay for both music and navigation, so as long as I could get that audio working, along with being able to make phone calls, then I would be happy. If it made life easier for figuring out wiring I could hide a couple of speakers under the dash for system tones to come out of.

Would you mind expanding on the options here as this sounds promising? Many thanks!

Not really related but the B&O system in my fiesta is crap, but then all the speakers are the same but with a B&O logo, the only difference is the sub and presumably a DSP/AMP of some sort.

What I found is upgrading the speakers appropriately and also upgrading the sub and sub amp will usually make a big improvement. If you really want to go for a high performance system, then obviously replacing the B&O (or Sony for the older ones) is necessary. Like any other manufacturer, the systems are engineered for cost and safety, not performance. In the US, the maximum SPL for production vehicles is 105 dB SPL. This is a little known fact as far as consumers are concerned, and it is not advertised by the vehicle manufacturers. This is a safety concern about being able to hear emergency vehicles and such.

For the B&O equipped vehicles, there are adapters which will convert the tones to be used with aftermarket equipment. There are several options, but one of the most common is the Zen.
Audio Interface - ZEN-A2B / DSP12A-A2B - NAV-TV ( There are cheaper options that will make no difference sonically in a vehicle environment.

For non-B&O equipped vehicles, the first step will be replacing the ACM with a model that has line output capability, if the existing ACM does not. You will need to find the part number of the ACM and determine if it is so equipped, otherwise you could use a Line Output Converter to bring the levels to the amplifier or DSP. Keep in mind that all LOC’s will introduce distortion and aliasing which will affect phasing and staging. It’s just a matter of how much. Plain physics…don’t believe the manufacturer hype.