Go back to stock head unit?

[ScottAZ]

The previous owner of my 02 put in a single DIN Sony head unit, presumably to gain Bluetooth connectivity. My car came with the Bose system and has the amp and CD changer in the frunk. The system sounds like complete garbage. The bass is distorted, there's a constant hiss and it just sounds flat.

I know very little about audio systems and their wiring. Is it safe to assume that the amp isn't being utilized with the aftermarket head unit? If so, I would be willing to forgo Bluetooth for better sound and would consider buying a replacement OEM head unit.

Any advice or suggestions? How can I determine if the amp is being utilized? Thanks!

[particlewave]

That hiss and distortion is the stock amp. Get rid of it, as it is weaker than the Sony HU built in amp, and sound will drastically improve.

Unplug the connectors from the amp. If you get no sound after that, the stock amp is being used.

[ScottAZ]

Originally Posted by particlewave

That hiss and distortion is the stock amp. Get rid of it, as it is weaker than the Sony HU built in amp, and sound will drastically improve.

Unplug the connectors from the amp. If you get no sound after that, the stock amp is being used.

Interesting! So if I find out that the amp is actually still connected (and therefore the source of the issues), and I unplug it and get no sound, how to I reconnect things, avoiding the amp? Sorry if that's a stupid question. I'm pretty ignorant with car audio.

[particlewave]

If that's the case, take pictures of the wire connectors coming out of the amp and I'll write up some instructions for you.

[ScottAZ]

Originally Posted by particlewave

If that's the case, take pictures of the wire connectors coming out of the amp and I'll write up some instructions for you.

Very kind, thank you sir! I'll get the car back tomorrow from the shop and will take a pic.

[azlvr]

I have a Sony HU along with alpine 150w a channel amp and high end speakers and sounds amazing.

[ScottAZ]

Originally Posted by azlvr

I have a Sony HU along with alpine 150w a channel amp and high end speakers and sounds amazing.

Did your car originally have the factory Bose system? If so, are you using the Bose sub?

[azlvr]

Originally Posted by ScottAZ

Did your car originally have the factory Bose system? If so, are you using the Bose sub?

No I didn’t have the Bose system but I have the 6 channel system.
I have hi quality 6.5 in speakers in doors that have lots of bass. I also don’t use the rear deck speakers.

[ScottAZ]

Originally Posted by particlewave

If that's the case, take pictures of the wire connectors coming out of the amp and I'll write up some instructions for you.

Here is what I'm working with. The amp is connected (pulled one of the wire harnesses and the sound was killed). After messing around with the EQ, the sound isn't completely terrible. FM and Bluetooth have more distortion and hissing than using a direct aux connection. I think that can probably be blamed on an weak early Bluetooth receiver and a less than ideal FM antenna.

Still, do you think bypassing the amp will help? The Bose sub is rattly and sounds like a fart even with the bass turned down and there is some hissing no matter what I do. I wonder if it's worth going around the amp. Thanks for the help!

[Cunningr]

My opinion is to bypass the amp and disconnect the bose sub if its making that much noise.

Just a visual the bottom connector are the wires that go to your speakers.

[ScottAZ]

Originally Posted by Cunningr

My opinion is to bypass the amp and disconnect the bose sub if its making that much noise.

Just a visual the bottom connector are the wires that go to your speakers.

Is bypassing the amp just a matter of moving wires around? Any guidance?

[Cunningr]

Well probably the easiest methid would be to run speaker wires from the speaker outputs on the head unit to where the connector is on the amp.

You could then just unplug the connector and go 2 or 3 inches back from the connector and splice into the wiring harness.

I am not familiar with the Bose wiring so might wait on Particle Wave to give some advice.


The other option would be run new speaker wires from hu to the speakers. The dash wings are easy enough. But getting into the door cavity is a pain.


I did a full upgrade:
Pioneer HU
Alpine pdx 9 amp
Hertz 3 way components 6.5 door, 3 inch mid and 1 inch tweeter dash.
Modified an old 996 cabriolet subwoofer box installed an 8” pioneer shallow mount sub driver. Had to stuff the box and use dynamat to clear some buzz in the box. Sounds really good now.
Cross over duties handled by the head unit.

[Cunningr]

so are the head units outs in use now to amp are the RCA connections? If not that could be some of your problem, the amp needs the lower power signal otherwise can inject noise.

[particlewave]

That Sony HU will definitely sound better on its own. I'll write up some directions for you tonight. It will involve splicing wires at the amp connector (no need to remove the stereo...all can be done in the front trunk).

[ScottAZ]

Originally Posted by particlewave

That Sony HU will definitely sound better on its own. I'll write up some directions for you tonight. It will involve splicing wires at the amp connector (no need to remove the stereo...all can be done in the front trunk).

Awesome, thank you VERY much!

[mgfranz]

I had a similar problem with my E34 BMW, I bypassed the issue by wiring the factory amp to be fed by speaker wire signals, ignoring the HU pre-amp outputs and letting the amp take simple feeds from the speaker outs.