Hey all,

Just installed a new Alpine 4ch amp for my speakers, but its making a whining noise from the speakers. Sounds exactly like interferance from the engine, so immediately thought of the earth. I checked it and its properly connected. So then I thought the power cable is too close to the audio cables, but they arent.

Could it be the headunit that is causing it? I dont think it can because its defo engine interferance noise, because once you turn off the engine it goes away.

Any ideas?

 

RCA's might be too close to a power or ground wire. Could also just be lesser-quality wires. Make sure they're well-shielded; home audio wiring won't cut it.

 

And also try an in-line noise surpressor to see if it helps.

 

99% of the time, it's a poor ground at either the headunit and/or the amplifier - I'd check all of your grounds again....

 

I'd make sure your grounds are on an unpainted point on the chassis. And your audio and your power wires are far enough apart.

 

Ok thanks for the advice guys, will double check everything again this week. Do you think engine earths could be doing it?

 

I agree it's probably the ground(s), [earth] and all grounds have to be good.

What kind of HU do you have? and how and where did you run the RCA leads and the amps main power cable?

Make & model numbers of the HU and amp would help, also what gauge is the power wire, and where exactly did you ground the amp and how, also how long is the amps ground lead? 94

 

i agree with whats said above. the whining noise is 99% of the time down to a bodge up or lazy install. cause of the whining noise is 99% more or less down to the grounding points. double check. and secondly make sure your rca cables are are running down the opposite side from the amp/power wire etc.

 

Earth ground in a car, did we all go mad why I was away?

You can not have an earth ground in a car, ok maybe a car thats dragging its tail pipe :D

You can have battery ground and chassis ground.

 

i agree with sir_teg. people get all excited and lazy and juss wanna install everything at that very moment. power should be run down the drivers side and rca's and speaker wire on the passenger side. also, make sure the amp is grounded well to the body or even sand some paint off.

 

The install was done by a friend that does installs for a living but my car is being weird. Everything is done properly with proper earths, and wiring done. Power is down the passenger side (UK car), and audio down the centre. The earth is connected well to the chassis, with a bolt and sanded the paint down.

The earth from the engine block to the slam panel is way too long tho, do ya reckon that would affect the earth for the audio in some way?

Heres a pic of it, if ya wanna see Its not being painted yet, getting done tommoz :D

 

It's always good to have the shortest ground possible

 

The current earth is about 8 inches long, too long?

 

that doesn't sound too bad.... what gauge is it... what is everything being grounded off of it

 

Its 8 gauge, each amp has a seperate ground.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">Earth ground in a car, did we all go mad why I was away?

You can not have an earth ground in a car, ok maybe a car thats dragging its tail pipe :D

You can have battery ground and chassis ground.</TD></TR></TABLE> LMAO, earth = ground, just like boot = trunk and bonnet = hood. Only in England you say? 94

 

Need some more info...

What is the make and model of your HU and the amps?

You say you just installed a "new" amp, does that mean you had another amp before and you replaced it, or is it all new?

It sounds like the install, [wiring] was all done properly, I would check the amp settings and the RCAs themselves, run another set from the HU to the amp, [just over the seats and everything just to eliminate them as the problem.

I would also try a "dump" ground, [16-18 gauge wire run from the chassis of the HU to the chassis of the amp]

Also one more question, is the chassis of the amp isolated from the chassis of the car? It looks like it in the pix, and should be. 94

 

to isolate where it is coming from, you can also unplug the rca's and listen for it. If the sound goes away, you know it is coming from the rca's or before. If it is still there with no rca's then it is a seperate issue. try disconnecting one speaker at a time, for example if you disconnect the front right speaker, and the whine dissapears from the other three, then the wire could possibly be shorting somewhere, I've seen speaker wires touching the chassis before and causing a whine.... if it is from the rca's and before, then unplug from the H/U (while plugged into the amp) and see if it's still there, if it is then run a new set of rca's (just throw them over the seats to test) and see if it goes away...

hopefully some of that helps.....