Im having trouble wiring up my subwoofers, its not so much the subs that are a problem. its when i hook up my mids and highs to the other amp i have set up there is a whistle that increases as i accelerate or hit the gas.

Ground Loop Noise...

It's usually caused by using too small gauge ground wire, too long ground wire, grounds that aren't grounded in a common spot in the car chasis, or just overall bad electrical wire/wiring...

Some simple solutions: Return ground... Take the ground of your radio/EQs and run it to the same spot you ground your amp... The amp's ground should be no longer than 12 inches total... The ground wire should be a larger gauge and properly grounded to the chasis using a star washer (be sure to strip any body paint where you make your ground connection by scratching the surface.) A car's chasis is a real electrical nightmare... As it's not a solid piece of metal and electrons have a hard time moving through it... The alternator whine you hear is the ground fluctuating from resistance through frame...


If you still have noise, bad components can be another issue... Cheaper quality components have bad circuit design as well as output impedances that don't match well with other components that can cause a lot of unwanted noise...

Use a capacitor (pricey) is another way to clean up your power and also delivers heavy current for when your woofer demands it... Smaller capacitors are best for noise, larger ones are better for power delivery... Depending on size of amp, installing a 1F capacitor in your power circuit can level out a lot of fluctuation as the cap induces more current as the demand calls for...

I had one system I worked on for a friend that he installed himself and had a problem with engine whine.. Found out it was his EQ... It was a bad component (cheap quality), I removed it and whine was gone completely...

Another cause sometimes is by running your power lines too close to your audio lines (low level RCA patch cord), you should run audio lines down one side of vehicle with your power down another... If this isn't possible, at least 6-8 inches away from each other minimum... Quality of patch cord can also be a problem... Better patch cords usually come with a ground wire as well to keep out unwanted noise...

Ground noise is one of the hardest things to fix...
Sometimes you can find the problem by getting a cheap pair of headphone with the padded cuffs that cover your ears to block out outside noise... Get an adapter from radio shack that will turn the 1/8" or the 1/4" plug into the RCA two plug style ends and unplug your systems cords at various spots and plug in your headphones and see if you can hear noise at various points in your setup... Sometimes helps to identify faulty components or bad cords...

I've been doing audio/video/security for almost 15 years and I still run into some systems that sometimes give me a headache trying to troubleshoot ground noise...

if your rcas and remote wire are on the same side with your power wire that could be the problem. move rcas and remote to other side of car to run to your amp.

This is being caused by the alternator. Easy fix. Just put a small capacitor on the alternator...the ones off of a Dodge 4.7l V8 intake ( near the coil ) work quite well.

This is ignition noise being amplified by the stereo. Most likely it is coming in on the power line to the amplifier (either the main unit in the dash, or an aux amp if you have one).

Talk to your local car stereo shop, and tell them what's happening. They will sell you a power line filter... basically a bunch of capacitors and/or inductors which smooth out the ignition noise so it doesn't get picked up by the amp.