Full range speaker output to tap into?

[deanproxy]

I’ve tapped into the factory subwoofer from the B&O system to install an amplifier and subwoofer. What I have noticed is Ford does some really weird things to the signal depending on the volume the system is at.

For instance, if the volume is around 12, most frequencies seem to have similar output, except at the 50hz range. It starts off with a large boost, then tapers down after a few seconds to normal levels. 30hz is much lower than other frequencies. Raise to volume to 18 or over, and 50hz gets significantly reduced in output, but 40hz stays consistent. At around 18 on the volume, 40hz is quite a bit louder than 50hz, but it’s the opposite at around 12.

I’m used to factory systems reducing output across all frequencies once the volume hits a certain level, and that can be combatted with AudioControls “AccuBass” but this weird manipulation of frequencies and the slow tapering over many seconds makes that close to impossible.

Does anyone know if the rear door speakers get full range without any crossover or strange DSP manipulations? Or, is anyone aware of a wiring harness to bypass all of this? I’ve googled around for a PAC interface but can’t seem to find one.

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[MUSTANGMICHAEL]

Ive used this line out converter on my explorer for that very reason. There is an adjustment that will compensate for the signal change/drop off. Ford seems to do this to stop bass distortion. This converter worked great for that.

 

[LaFong]

I just did a test with a 40Hz signal, using the subwoofer wires:

Volume	Initial Voltage	Final Voltage
6​	1.5​	1.5​
8​	2.45​	2.45​
10​	4.14​	4.14​
12​	6​	6​
14​	8​	8​
15​	9.1​	9.1​
16​	11.1​	10.3​
17​	13.3​	10.3​
18​	15.8​	10.3​
19​	16.7​	10.3​

It took about 15 seconds before the voltage dropped at volume 16, scrunched video below. At higher volumes the dropoff began more quickly, by 20 it was pretty much immediate. These guys, Factory Connection Harness to add a new Subwoofer Amplifier while retaining factory B&O, sell a harness combined with Kicker KEYLOC. They have dealt with the F150 B&O, and claim this setup will fix it for the F150. Not sure if the MME is any different. I have asked them if my methodology is sound.

 

[deanproxy]

Oddly enough, 40hz and below are the least attenuated. 50hz and 63hz take a significant reduction. Both are within the realm of subwoofer frequencies as it’s quite common to set crossovers at 80hz.

I’m taking voltage reading from my external amplifier, so my starting voltages are naturally much higher, but at 63hz and 23 on the head unit volume, It starts at 50v and after 15 seconds is attenuated down to 11v!! For 50hz it starts at 50v and goes down to 18v! 40hz starts around 52v and gets dropped to 38v. 31hz starts at 44v and goes down to 38v. So while those Lower frequencies take a hit, it’s the upper frequencies that are virtually turned off after 15 seconds of loud volume.

 

[deanproxy]

I just did a test with a 40Hz signal, using the subwoofer wires:

Volume	Initial Voltage	Final Voltage
6​	1.5​	1.5​
8​	2.45​	2.45​
10​	4.14​	4.14​
12​	6​	6​
14​	8​	8​
15​	9.1​	9.1​
16​	11.1​	10.3​
17​	13.3​	10.3​
18​	15.8​	10.3​
19​	16.7​	10.3​

It took about 15 seconds before the voltage dropped at volume 16, scrunched video below. At higher volumes the dropoff began more quickly, by 20 it was pretty much immediate. These guys, Factory Connection Harness to add a new Subwoofer Amplifier while retaining factory B&O, sell a harness combined with Kicker KEYLOC. They have dealt with the F150 B&O, and claim this setup will fix it for the F150. Not sure if the MME is any different. I have asked them if my methodology is sound.

Thank you for the link. I ordered it. I’ll post on how it ends up working!

 

[mkhuffman]

I’ve tapped into the factory subwoofer from the B&O system to install an amplifier and subwoofer. What I have noticed is Ford does some really weird things to the signal depending on the volume the system is at.

For instance, if the volume is around 12, most frequencies seem to have similar output, except at the 50hz range. It starts off with a large boost, then tapers down after a few seconds to normal levels. 30hz is much lower than other frequencies. Raise to volume to 18 or over, and 50hz gets significantly reduced in output, but 40hz stays consistent. At around 18 on the volume, 40hz is quite a bit louder than 50hz, but it’s the opposite at around 12.

I’m used to factory systems reducing output across all frequencies once the volume hits a certain level, and that can be combatted with AudioControls “AccuBass” but this weird manipulation of frequencies and the slow tapering over many seconds makes that close to impossible.

Does anyone know if the rear door speakers get full range without any crossover or strange DSP manipulations? Or, is anyone aware of a wiring harness to bypass all of this? I’ve googled around for a PAC interface but can’t seem to find one.

I didn't take any measurements, but I am very confident that the door speakers have serious bass attenuation, as expected. When I first connected my subwoofer, I tapped into the front door speakers. My subwoofer struggled. When I switched to the subwoofer outputs the bass was much better.

Certainly this is subjective, but I think the door speakers are not a good source for a subwoofer.

 

[deanproxy]

I didn't take any measurements, but I am very confident that the door speakers have serious bass attenuation, as expected. When I first connected my subwoofer, I tapped into the front door speakers. My subwoofer struggled. When I switched to the subwoofer outputs the bass was much better.

Certainly this is subjective, but I think the door speakers are not a good source for a subwoofer.

Yeah, you’re right. They are very attenuated below 80hz. It’s ridiculous the Ford creates these “premium” systems and the attenuates them because they’re no better than any other crap system in any other car. I’m also really surprised B&O would put their stamp on a system like this. Ford must be paying them a ton to turn their head while they put their mark in such an underwhelming monstrosity.

 

[LaFong]

I didn't take any measurements, but I am very confident that the door speakers have serious bass attenuation, as expected. When I first connected my subwoofer, I tapped into the front door speakers. My subwoofer struggled. When I switched to the subwoofer outputs the bass was much better.

Certainly this is subjective, but I think the door speakers are not a good source for a subwoofer.

The way the device above is supposed to work is to take the door speaker bass to reconstruct bass level. The bass in the door speakers is much less, but it is consistent. Trying to un-DSP the factory amp subwoofer output would be difficult given the time variable involved. I have no idea how well the KEYLOC approach will work, but @deanproxy will let us know. I always like it when someone else is the guinea pig.

 

[LaFong]

Don @SoundsGoodStereo thinks their harness and KeyLOC should work, I gotta believe it will be better than factory, we'll soon know.

 

[deanproxy]

Don @SoundsGoodStereo thinks their harness and KeyLOC should work, I gotta believe it will be better than factory, we'll soon know.

Convince Don to ship my harness overnight and I’ll let you know faster! ?

 

[Sillybibbles]

I tapped my stock entry level system's left rear door for a line level input to a sub and it worked well. From what I can tell the rear side doors on the non-B&O system don't have any high-pass filter/bass removal.

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