Engine Noise

[GGnz]

I know this has probably been covered before but want to be sure. What are the main causes for engine noise through your speakers? I know that the ground can be and running your wires beside the RCA's.

I just installed my new custom parcel tray today and front speakers are producing engine noise.

Is it possible that the ground connection could be loose and it causing this? Also would the battery connection affect it at all.

Sounds also work fine when car is turned off. Its only when the car is running.

So what causes engine noise? Just so I can eliminate any problems.

Also it wouldn't be a amp problem would it? The amp should be fine?

Thanks for any help.

[Jazza]

Put your wiring down the opposite side of the car to your battery to your battery usually solves it - but ive never seen it happen in the front speakers...

[Alex B]

All amps grounded at the same spot? Removed paint at the earthing points? Other options are to fit a suppressor to teh alternator. Can buy them from HDL.

[sergei]

The cause of the whine in speakers is/are the ground loop(s), basically with sensitive input of amplifier (and being cheap design, because ground of the RCA cable is not isolated from ground of amp itself) the RCA shielding acts as an antenna and picks up the EM interference, cheap way to fix it is not to connect fully RCA (so the centre contact will touch the contact in the amp, while outer contact will remain unconnected), other way (proper) is to introduce 1:1 audio transformer in between amp and source.
Noise supressors will do nothing, as RCA leads actually picking up "air" interference (not power supply) - good example is when RCA close to power cable there is more interference - interference is radiated from power cable into "air"...
You can get "CAR STEREO LINE ISOLATION TRANSFORMER" from jaycar, just go and ask for it, it will be ~$30 for unit (wich has 2 RCA inputs and 2 RCA outputs)...

[GGnz]

Haven't removed paint. I had the Batt and ground wires running down passengers side and the RCA's running up the middle.

Would having the speaker output wires from the amp and RCA's together affect it?

Also could it be that a the grounc cable is loose somewhere.

I think its the ground as such but I haven't actually touched it

[Snoozin]

You have a ground wire for the amps running the entire length of the car?

[GGnz]

Nope just at the back. Grounded under the seats. Ground wire terminal in amp is slightly loose now though. Will have a look tomorrow and let you know.

[GGnz]

On another note, when HU is off, static type noise comes through the tweeters still. No HU motor noises coming through the speakers etc. so must definately be the ground. Maybe because the Power wire and speaker wires running from the amp are tangled to. Will redo my grounds and check wiring. If anyone else has any suggestions please let me know. Just may pay to check everything to avoid this happening again.

Cheers,
Gareth

[Snoozin]

Re do ALL the grounds on the car.

[pc]

I had the same problem in my car years ago, the whine would go up in pitch with the engine, I figured it was the ignition system or alternater. After checking my supply and grounds I spoke to a mate who works in car stereos, and he got me to make something up that uses a capaciter on the supply lead, and a ferrite clamp (maybe, I can't remember what else was involved). This fixed the problem.