New headunit...volume is going crazy - United Bimmer Community

**Linds** · 10-22-2006, 09:42 AM

Background: (don't have to read this)

Ok, so basically the previous owner of my car was a moron and did a terrible job installing a shitty amp and speakers (and either did not change out the headunit, which seems unlikely, or threw the stock one back in before he sold it). Anyway, the stock one finally crapped out on me, so I bought a Sony headunit...erm, because it lights up red which matches the interior, lol.

Problem:

When I was driving home, the volume started going nuts. I would turn it to a number, then all of a sudden it gets really low all by itself. The number doesn't go down, but it gets quieter. So then, I'll turn it up, and it'll crackle (which is a sign of the amp going bad, I think?) and the volume will shoot way up after I've stopped turning the knob. So, I'll turn the knob back down and it'll be ok for a few seconds (usually 10-30) and then without me touching anything the volume shoots up really high again.

Help!

witeshark · 10-22-2006, 09:46 AM

I have a similar problem. And with it a very high pitch squeal that just randomly starts and stopped. Not sure of a fix. My stereo fixed it all by quitting altogether

**RSF5** · 10-22-2006, 10:28 AM

Wait does the volume on the headunit shoot up by it's self? can you see the volume numbers going up? I would think it would be a bad amp.

**Dudesky** · 10-22-2006, 10:46 AM

Sounds like incorrect wiring. It would help if you described in detail how the new HU was connected.

**Linds** · 10-22-2006, 10:51 AM

Yeah, the volume goes up by itself but I don't think the numbers go up. I'm gonna go out in a minute and look.

I didn't install it so I don't know if I can describe how it was connected. It was free installation, so I figured, why not? This is why not, lol. But, if you guys know some specific things I can look for that would help, I can do that.

**c1apton** · 10-22-2006, 11:10 AM

volume "hunting" is a sign of a cable(s) or possibly an amp going bad. Cables and or a loose connection will do the same thing. Look for a pinched cable (speaker cable)

**Linds** · 10-22-2006, 11:18 AM

Ok, thanks, c1apton. Does it help to know that none of this was happening with the stock radio? Also, I double checked and the numbers don't move when the volume rises and falls by itself. Also, it happens with cds, the radio, my mp3 player...

**Rooz** · 10-22-2006, 11:18 AM

you need a device called an XR4

**Linds** · 10-22-2006, 11:38 AM

This? Even though it's an aftermarket amp? I guess what I'm asking is if it would be better to just get a new amp and if I did would I still need the XR4?

**Rooz** · 10-22-2006, 01:10 PM

Might just be that the amp is setup wrong... and also, I would sure hope so, but on your car, what really needs to be done is that the factory amp should have been by-passed. But yes, that is an XR4

**RSF5** · 10-22-2006, 02:58 PM

^^^

of course Rooz knows what he needs exactly...

**xsperf** · 10-22-2006, 04:46 PM

ya, listen to rooz lol

**Linds** · 10-22-2006, 05:58 PM

Thanks for all the advice! I'm gonna have my friend, who works in car audio, look at it tomorrow to see if the wiring is all ok, and then go from there. He's been wanting to rip apart my car anyway to figure out what the previous owner did, so this is the perfect opportunity.

**BMWLotAttendant** · 10-22-2006, 07:19 PM

Sounds like an amp to me. Heard it in several e39s.

The e46s volume is sometimes screwed up too...when I want to turn it down it goes all the way up. Wowzers!

Rooz knows what he's talking about. But I'd get an amp before getting the XR4. After the amp, if you are still having problems...then get the XR4.

**Linds** · 10-22-2006, 08:40 PM

Oh, I forgot that my rear speakers also don't work. Probably doesn't change the diagnosis, unfortunately. Ugh, I don't wanna have to buy an amp right now.