Weird feedback/chatter through subwoofer

[tesko]

This is on a 2003 530i, equipped with DSP. I've been getting this weird noise going on through the driver side sub, I replaced the subs with 10's but it's still happening.

Check out this video (this is with the audio OFF):

https://www.youtube.com/watch?v=8dpAAkG8vIg

It'll do this intermittently, and sometimes it'll be a constant pulsing.

I'm no expert on car audio, but I'm guessing an issue with the DSP amp or wiring? Any help is appreciated.

[DennisCooper]

Hi,

To test, you'll need to swap your OEM DSP amp out with another known working one. If then it stops, you know it's your unit that's got a fault in it/becoming more faulty. Given the age of these unit's nowadays you'll need to hope the replacement you buy doesn't begin to fail as well. If the noise continues, you've perhaps got some interference somewhere along the signal to the aftermarket amplifier you are using to drive the new Rockford subs - which I'll assume you have installed. Check all connections, move the signal wires to the aftermarket amplifier to see if that helps. Similarly, another unit the OEM setup might also be the cause and is failing, so you'll need to swap those out with known working ones in order to test which one(s) and then subsequently replace.

Update the thread as you move through the fault finding phase and/if you resolve etc.

Cheers, Dennis!

[tesko]

Hey Dennis, thanks for the reply. FYI there is no aftermarket amplifier installed. Only mods to the audio system are the dual 10" Rockford fosgate subs, and I replaced the rears with Alpine 5.25"s.
Unfortunately I have no way of getting a good working DSP amp locally, I'd have to buy one online and wait for it to ship. If I went that route, would I need to have it coded to the car?

[DennisCooper]

Hi,

For now you'll be focusing on what the issue is, and it's looking more likely it is the DSP amp and it's perhaps showing signs it's on it's last legs as it were. The OEM DSP amp doesn't really provide enough RMS power output to provide good levels of sub bass - being around 80W RMS I think it is. You'll need to research on this forum for DSP amplifiers as I think if you got one from an E53 X5, it'd need coding and also, I think there's variations between E39 DSP amplifiers throughout the production years, so you'll ideally get exactly the same version you have. If you get a different year E39 unit, it may need coding. Again, please do your research on this.

Cheers, Dennis!

[JaxPlanet]

I had noise when I plugged an iPod adapter into the CD Changer's connector. The solution was to shorten the ground wire. I clipped the ground wire on the plug and ran it to a nearby grounding point.

Here's a good resource for eliminating noise:
https://midimagic.sgc-hosting.com/nonoise.htm

[tesko]

I had noise when I plugged an iPod adapter into the CD Changer's connector. The solution was to shorten the ground wire. I clipped the ground wire on the plug and ran it to a nearby grounding point.

Here's a good resource for eliminating noise:
https://midimagic.sgc-hosting.com/nonoise.htm

Thanks man! I will check it out, appreciate a helpful reply!