Very noisy

[MD13 459]

Ok so I finally finished installing some gear in the car (e30 coupe):

New Pioneer headunit

600WRMS DD Amp

Sub in box

50WRMS x2 @ 4ohm amp

Lots of wiring...

Sounds fine with the engine off but horrible with the engine running. I'm guessing the noise, which is coming out of the drivers kick panel front, is due to laying the speaker cable down the drivers side near the main power cable? Has anyone run cable down the drivers side without issue or special cable?

I really only amped the front speakers (Infinity Kappas) as I had a 2 channel amp lying spare. If you have to run all the speaker cable down the passenger side I might flag it... Any helpful advice appreciated.

(Noise is constant tapping - no change with volume control)

Edited July 9, 2012 by MD13

[MD13 459]

bump

[_ethrty-Andy_ 2122]

I ran my power down the drivers and signal down the passengers but my battery was in the front. is the amp wired to the battery in the boot or to the + terminal in the engine bay?

It is plausable that the interferance is picked up on the system, but youd have to have a large gain on the amp. try turning down the gain on the amp and then on the head unit setting the bias towards the non-amped speakers, and then turning the volume up further on the head unit. or just get rid of the front amp. a waste of time if the back isnt amped too

[MD13 459]

Amps are wired to the battery in the boot via a distribution block. Ground is to the main ground in the boot also.

Assuming I get it going I was going to ditch the rear speakers - just leave the speaker grill in place and let the sub sound out the parcel tray holes. Having just put the interior back together I don't feel like taking it all apart again to lay the drivers side cable down the passengers...

[huff3r 347]

Check for possible accidental groundings on the front speakers and/or cables.

[Neal 512]

Wouldn't expect a speaker wire to pick up that much emf from having path next to Battery cable. RCA links possbily

Things to check with engine running.

1,(Check right speaker connections) Make sure that the speaker terminal / amp speaker terminals connections haven't been grounded if not then carry on with these steps

2( Determining if noise is on amp output or input stage), Swap left and right front speaker terminals. Does the noise swap channels ? if yes do the next test, if no possible speaker to chasis short elsewhere between amp and speaker or amp has right channel problem.

3,(Determinig if noise is RCA lead or head unit) Swap left front and right front RCA's , Does the noise swap channels ? if yes then your poblem is right channel RCA lead or head unit noise out of right channel..

4,( Determing if noise is RCA lead or Head Unit output) Pop out head unit. Unplug right channel RCA.

5, Plug left channel RCA into head unit Front Right. If the sound is clean then it's your right RCA. If not it's coming fron the Head unit right channel pre-out.

6 , If it's the head unit then recheck all of your head unit wiring. If this is all ok then then noise supressors may help or rca line loop isolators.

http://www.crutchfield.com/p_003S15A/Ameri...tt.html?tp=2653

http://www.crutchfield.com/p_127SNI1/PAC-SNI-1.html?tp=2653

[rogan 1]

Pop headunit out and run a wire from the outisde sheath of one of the rca outputs to the headunit earth.

In pioneer headunits theres a fusible link (otherwise known as the pico fuse) on the rca earth track inside the headunit. Common pioneer issue and symptoms are alternator whine, on/off thump, and cd tracking noise.

[MD13 459]

You mean this Rogan?

You and Neal both suspect RCA's so I'll check that out. On that front I'm running the rca's on top of the glove box beside the engine management module (at least I think that's what the box is...) to the top of the passenger kick panel and then along the passenger sill alongide the left front speaker wire - is that ok?

[rogan 1]

That's OTT and bogan. All -ve RCA outs are daisy chained inside the headie so you only need to earth one of them and doesn't matter which.

Just slip a thin and small length of wire inside on of the RCAs you're using (making sure it doesn't touch the inner pin which is the +ve) and earth that as a test. If the noises go away then you can either send it off to be fixed (Pioneer techs replace the fuse with straight wire) or you just get a cheap RCA cable and butcher the end off to make a RCA -ve to earth cable. Note this has to be at the headunit, not at the amplifier.

I don't suspect the RCA cables from headie to amp.

With a Pioneer headunit, the first place to start is the fusible link. Then follow Neal's troubleshoot.

Edited July 9, 2012 by rogan

[MD13 459]

Pico fuse seems fine - low resistance between rca shield and headunit chassis. Noise is both front speakers... If I fade out the fronts i still hear it. No noise if I pull the front rca's off headunit.

Swapped rca's between sub amp and front amp for cable fault - no change. Tried one channel from the headunit at a time - noise from both. Confused...

Suppose I'll go back to running the fronts off the headunit and pull the amp out.

Edited July 14, 2012 by MD13

[rogan 1]

Is that low resistance between rca shield and headunit chassis with any of the RCAs plugged in or all of them unplugged?

[MD13 459]

All plugged in and one unplugged. I think I see where you're going...

With at least one plugged in ground is provided by the amp right? Bugger.

Too late now. 1 amp and all it's cabling removed.

Edited July 14, 2012 by MD13

[rogan 1]

With at least one plugged in ground is provided by the amp right? Bugger.

Exactly. Try with all unplugged.

[MD13 459]

Resistance was still low with rca's removed.