Rear speakers don't work due to PO's subwoofer install - ideas?

[irocz0r]

UPDATE: A user below pointed out my amp has space for two more speakers (see photo below). I tried to hook 2 new 4-ohm speakers directly up to the amp, but this didn't work. What else do I need to get the speakers working? Here is the instruction manual for the amp, if that helps: https://www.manualslib.com/products/...q-3270859.html

So my car came with an aftermarket sound system installed in the trunk. It appears the PO must have tapped into and disabled the rear speakers in order to make the sound system work. I assume he just didn't care about the rear speakers.

I would love to have the rear speakers working, but I have no idea where to begin looking for how to get them playing music again. All I have determined so far is that 1) when I test the rear speakers with a multimeter, there is no voltage going to them, and 2) I found one tapped ground wire which leads to the rear speakers.

Anybody have ideas on how to troubleshoot this?


And here's the whole system. I always thought it was odd it had two giant amps for one 10" sub, but I suppose it's because these components are probably about 10 years old+? I've had a much smaller amp to push two 12"s before so this set up has always struck me as odd.



So any ideas?

[Mwishlist]

So from the pic your system is this:

• Radio to Audiobahn (chrome monstrosity) 4 channel amp?
• Two Audiobahn channels feed the Zapco crossovers which go to the front component speakers (the speaker wires wrapped in red and yellow tape are from amp to xover)
• Two Audiobahn channels appear to be unused (the connectors directly under where the red and yellow tape speaker wires connect to the amp)
• Then the Power 1050 one channel amp which runs the sub. Edit: I looked at a pic of the audiobahn inputs, I am guessing there are two separate RCA cables from the radio; one set goes to the speakers amp and the other to the sub amp.

The good news is that it looks like the Audiobahn amp has two channels that aren't hooked up. So if that is the case, simply connect a speaker to the unused channels on the chrome monstrosity and see if you get sound. If so, the simplest way to add rear speakers without digging fully into the rats nest; would be run new speaker wires from the audiobahn to each of the rear speakers. Done.

[irocz0r]

I only see one
set of RCAs so I am not sure if the pic doesn't show both or if the radio signal runs into the Audiobahn and then it outputs to the mono amp.

I have two more RCAs behind the radio from when I installed my headunit, so there are two more you can't see.

You explanation of what the components do was very illuminating. I never considered one amp powers the sub, and the other amp powers the upgraded front speakers. Thanks for that list!

The good news is that it looks like the Audiobahn amp has two channels that aren't hooked up. So if that is the case, simply connect a speaker to the unused channels on the chrome monstrosity and see if you get sound. If so, the simplest way to add rear speakers without digging fully into the rats nest; would be run new speaker wires from the audiobahn to each of the rear speakers. Done.

That's a great idea! I'm a little unclear on the specifics though. Is it really as easy as running positive and negative wires from the amp to the stock speakers? There must be more to it than that. Do I need to add RCAs there as well?

[Mwishlist]

I'm no expert on the stock systems honestly, I've never worked on an e30 that had original stereo components in them. So yes, it should literally be that easy, but I am not sure how many ohms the stock speakers are, I think they are 3 ohms.

I am sure George or someone can chime in. If you can check the ohms with a meter I am pretty sure that amp can't handle below 4 ohms and the factory ones are 3. It may not be a big deal but it may be part of the reason the PO never hooked them up considering there are two channels just sitting there.

If it were me I would test the two extra channels on the amp and make sure they work and are good. Then I would buy a cheap set of components or co-ax speakers and replace the stock back deck speakers.

[Mwishlist]

On the RCA question, it may (should) run all four speakers front and back off the one RCA currenlty plugged in. But if you want the ability to fade from the front to rear, you would need another set of RCAs. Run that from the rear output on you head unit to the rear or speaker 3 & 4 input on the Audiobahn. That would let you control everything separately.

[irocz0r]

I bought some 4-ohm 5.25" co-ax Kicker speakers, the cool thing about them is they fit into the stock rear speaker housings, so it will be a clean look.

Unfortunately, I hooked the speakers directly up to the empty channels on the amp, and there's no sound coming out of them.

Any ideas?

[irocz0r]

I got the rear speakers working by using a couple Y splitter cables to double the front RCA signal to channels 3/4. Thanks for the help!

[Mwishlist]

Awesome! Glad I could help you get it figured out. Yeah, next time you have to pull the stereo or whatever, you can run a second set of RCAs from the rear output of the head unit to channels 3 and 4 on the amp, if you want the ability to fade from front to rear.

But if you have them set where you want them volume wise compared to the front with that gains on the amp, then you are golden.