Aftermarket amp to factory speakers

[RyanAir]

Hello guys!

Sorry if I've posted in the wrong section.

So, I installed an aftermarket head-unit, amplifier and subwoofer to my B7 A4 (2005, non-BOSE speakers - only the rear speakers are amplified, along with subwoofer)
My rear speakers do not put out as much sound as the front ones, because of the factory amp I guess. As I already have an aftermarket amp (for my aftermarket subwoofer), with 4 channels, is it possible to wire this AM amplifier to the factory speakers? If yes, how?
Or should I just connect the rear speakers directly to the HU (as the front ones are) ?

[Audibot]

Check out the audio forum; I'm sure there are plenty of examples to draw from.

[RyanAir]

I did. I only found how to connect an AM amp to a stock HU. As an AM head-unit is a bit different, I thought some changes may be required (such as not using a HI-LO converter) and then I have some unanswered questions. What should I actually use?
I guess it should be pretty basic actually. Just running the cables from the AM amplifier to the rear speakers wiring, but then again, I'm not so sure about what to do with the factory amp.

[Matt Devo]

you've got a few options:

- use an adjustable hi-low converter to feed the low-level input of stock amp with the speaker-level output of the aftermarket HU. Enfig sells a harness for this I believe
- feed the rear speakers directly from the head unit; requires running speaker wires from the HU to the rear doors
- feed the rear speakers from your aftermarket amp; depending on how this is fed now, may need to run RCAs from the HU to the amp, then speaker wire from amp to speakers (or tap into existing wires at factory amp, and just unplug connector from amp)

[RyanAir]

I am currently running RCAs from the HU to the AM amp (which in turn is wired to the subwoofer). I can just wire the amp to the speakers using the existing factory amp wires? That simple? Basically like the factory amp doesn't even exist, just that I don't have to run another set of cables directly to the speakers.

[Matt Devo]

I am currently running RCAs from the HU to the AM amp (which in turn is wired to the subwoofer). I can just wire the amp to the speakers using the existing factory amp wires? That simple? Basically like the factory amp doesn't even exist, just that I don't have to run another set of cables directly to the speakers.

assuming the RCAs from the HU to AM amp are for the rears (or rears and sub), then yes you could just run speaker wire from AM amp to factory amp location and tap/splice/etc. I did that for a friend's B6 (w/Bose, so did front and rear like that) and it's worked perfectly well for years now

[RyanAir]

Will do that. Sunday I'll have some free time and I'll report back if it's worked.

[RyanAir]

So I tried doing that. I connected speaker wire to the amp connector and I get absolutely no sound. And the pinout isn't exactly like on the B6. I seem to not have some pins where on BY they should be

[VinnysS4]

I'm running a JL Audio door speaker amp. I ran wires to the stock amp connector and spliced into the speaker wires at the factory amp. Has worked for years now without issue.

Sent from my SM-N920V using Tapatalk

[RyanAir]

I did just that. Except I didn't splice the wires. I connected it on the blue factory amp connector.
It would've been useless to splice the wires if this hadn't worked. And I couldn't find a pinout. I only found one for B6 but they are a bit different. They look the same but we don't have the same pins - I'm missing some

After trying literally every pin on the blue connector, none worked. I would get no sound, or instead of the rear speakers outputting sound, it would take sound away from, e.g. the right front speaker.

I had a Concert II - 1DIN on the car, if that matters

[VinnysS4]

I used wire taps. They clamp over the factory wire and you insert the wire you want to connect it with. This was obviously after testing the wires to the speakers first. That way i can undo it, throw a little liquid tape on them and be back to stock.

Sent from my SM-N920V using Tapatalk

[RyanAir]

Assuming I got no sound when connecting to the factory connector. I wouldn't get any sound connecting straight to the wire. Isn't that right ?

[RyanAir]

I think I found the issue. I had only 2 sets of RCAs run from the HU. So I bought a splitter wire in order to split the 2 RCA cables into 4, so all the channels on my amplifier would be used.
Basically I was using channel 1 (or 2) for my subwoofer and I think I ran wires from channel 3 or 4 to my speakers (but RCA inputs were only on Ch1 and Ch2)

And does anyone have an exact pinout for the B7 non-Bose amplifier ? It looks exactly like the one on the B6, but the pin's locations are different. E.g. Pin 21 on the B6 (RR-) is absent - I have no pin there - on my factory connector. Basically I'm missing every other pin (maybe it's just the order that is different?)

And what does "right / left rear signal from radio" refer to?
Do I run wires from amp to pins 1, 2, and 3 (right / left rear signal from radio + ground) or to pins 20, 21 (out of which one is absent; valid for LR and Sub too)?

Photo of the pinout

// if any moderator is reading this, can this topic be moved in the regular A4 B7 section?

[Matt Devo]

I think I found the issue. I had only 2 sets of RCAs run from the HU. So I bought a splitter wire in order to split the 2 RCA cables into 4, so all the channels on my amplifier would be used.
Basically I was using channel 1 (or 2) for my subwoofer and I think I ran wires from channel 3 or 4 to my speakers (but RCA inputs were only on Ch1 and Ch2)

And does anyone have an exact pinout for the B7 non-Bose amplifier ? It looks exactly like the one on the B6, but the pin's locations are different. E.g. Pin 21 on the B6 (RR-) is absent - I have no pin there - on my factory connector. Basically I'm missing every other pin (maybe it's just the order that is different?)

And what does "right / left rear signal from radio" refer to?
Do I run wires from amp to pins 1, 2, and 3 (right / left rear signal from radio + ground) or to pins 20, 21 (out of which one is absent; valid for LR and Sub too)?

Photo of the pinout

// if any moderator is reading this, can this topic be moved in the regular A4 B7 section?

you would wire the L/R speaker outputs of the amp to pins 17/18 (L) and 20/21 (R) on the stock amp wiring harness. The bentley manual only shows one non-Bose amp config for the B6/B7. Can you take a pic of your amp connector and wiring plug?

[RyanAir]

you would wire the L/R speaker outputs of the amp to pins 17/18 (L) and 20/21 (R) on the stock amp wiring harness. The bentley manual only shows one non-Bose amp config for the B6/B7. Can you take a pic of your amp connector and wiring plug?

Sure. I will, but tomorrow. Basically, the way the connector is in the photo I posted above , I am missing every top pin. If in the photo pin 17 is the (-), there isn't on my harness (it's like it's flipped upside down, although I'm sure I'm holding it correctly)

[lOPEZY]

Sure. I will, but tomorrow. Basically, the way the connector is in the photo I posted above , I am missing every top pin. If in the photo pin 17 is the (-), there isn't on my harness (it's like it's flipped upside down, although I'm sure I'm holding it correctly)

Old thread.. but I ran into the exact same issue(s) you had.. Our connectors (mine & yours) seem to be the same All top rows are blanks except #1... I only have pins (1,2,3,7, 13,14,16, 17, 19,20,22,23) populated. The rest are blank.. I'm going to assume for the 2008 B7 non-bose, that 16(LR+), 17(LR-), 19(RR+), 20(RR-).. will update ...