New deck lack power to the speakers (Sony CDX-S2000 in BMW e34, original speakers)

**Ken1** · 11-11-2007, 02:44 PM

I recently bought a used Sony CDX-S2000 to use in my BMW e34. The problem is that it seems like it really lacks speaker power. I have to turn the volume up to 3/4 to hear it, and to maximum to have a comfortable sound level. At 3/4 the sound is pretty good quality (although very silent), but when turned up it gets really raspy.

As some of you might know the original e34 speakers only take + from the deck, negative is wired from somewhere else. Could the Sony deck have a problem with this?

The Pioneer cassette deck I got with the car has no problems with it what so ever, and the sound is very clear and good considering it still has the original speakers.

**Ken1** · 11-13-2007, 03:40 AM

Anyone? I'd really apprechiate some help.

**doogieb** · 11-13-2007, 02:30 PM

You'd maybe be better asking on bimmerboard.com or bimmer.info.

I used to have an E34 (I have an E32 now) - do you have the setup with the factory installed amp (in the boot behind a carpet panel on the left side) or just a normal direct feed from the head unit?

The shared negative thing doesn't sound right, and certainly isn't how mine is wired, but mine had aftermarket speakers when I bought it.

**Ken1** · 11-14-2007, 01:33 AM

Thank you, I will give it a shot on those boards too. As far as I know I have a completely stock setup, except for the head unit. I found an article on the shared negative on E34's somewhere, so I think it's factory. I don't understand why they have to do things i such a hard way

**john05srt4** · 11-14-2007, 02:19 PM

Could it be because of the OHM mismatch rating between the headunit and speakers?

**Ken1** · 11-15-2007, 02:41 AM

Originally Posted by john05srt4

Could it be because of the OHM mismatch rating between the headunit and speakers?

Hmm, the deck is indeed a lot newer than the car (speakers). Is there any way to find out, or try to syncronize them?

**pokki** · 11-15-2007, 02:52 AM

Changing speaker impedence is not a simply task, so don't even bother looking into it.

However you can check their ohm rating with a multimeter. Disconnect the speaker from the headunit. Set your multimeter to measure ohms. Put your multimeter wires across the speaker wires. It won't be 100% accurate but will give you a close enough ohm rating.

You new headunit will be designed to drive 4ohm speakers.

**Ken1** · 11-15-2007, 04:00 AM

Originally Posted by pokki

Changing speaker impedence is not a simply task, so don't even bother looking into it.

However you can check their ohm rating with a multimeter. Disconnect the speaker from the headunit. Set your multimeter to measure ohms. Put your multimeter wires across the speaker wires. It won't be 100% accurate but will give you a close enough ohm rating.

You new headunit will be designed to drive 4ohm speakers.

Thank you, I will have to try that.

**walky_talky20** · 11-19-2007, 12:42 AM

The answer is yes. If the original radio only sent a positive signal to the speakers and they got a ground somewhere else, it is called a "common ground" system. Your new sony deck is not designed for this. I did an install in an e30 with a similar issue. On the dashboard there was a "fader" switch that faded the audio from back to front. I had to disconnect this switch in order to connect each speaker indiviually to the outputs of the new stereo (the switch just "split" the signal to go to the rear). It definitely sounds like you've got some impedance problems (running more than 1 speaker off of each output) or a common ground issue. If you can get it wired correctly I think you'll be much happier.

Without knowing the year and model of your car it is hard to be more specific about what you are dealing with here.

Hope this helps
walky_talky20