Speaker Hum (Goes up with RPMs...weird)

[psychotic]

I installed my new audiobahn components along with my amp. They take 160 each rms, and the amp puts out 2x150 rms or like 800 rms x 1. Anyways, there is a high pitched hum coming out of them (everthing is wired correct I've double checked). It is louder out of the tweeter, but i believe thats because it is a high pitched noise. Anyways, as the rpms of my explorer go up, so does the tone/volume of the noise. It must be getting some sort of signal from the engine??? A friend said he had heard of it before... something about a possible bad alternator. Any ideas????

 

[Robb]

It is pretty common. I would make sure you don't have any power wires near patch cords or speaker wires and check your ground at the amp. Highly unlikely that your alternator is bad.

Robb

 

[B94Sport]

I had that same problem. I didn't have any power or ground wires near signal cables, and relocating my grounding points did not change the problem. I ended up buying a ground loop isolator from Radioshack (also availble at Wal*Mart) for about $14 and it fixed the problem immediately!

 

[psychotic]

my ground is being shared with the ground from my other, weaker amp. I'm guessing that would be a problem??? I'm just scared to drill into the metal

 

[KEbert]

It does sound like a bad ground. Drilling another hole isn't a big deal. Just make sure theres nothing behind it.

 

[WoodysX]

Yea make sure you have those X-ray goggles also...no but anyway, good a good place to put a ground is behind your seats under that flap where the seat belts are, make sure you sandpaper off ANY and ALL paint for a good ground.

 

[hrbib21]

Yes, I just did the same thing. Grounded it to the floor behind/under the rear seat on the angled portion that goes up to the hatch area. Sand it down well and use a self tapping screw. Cleared the whine/hum completely.

 

[B94Sport]

Sharing a ground between two amps may lead to the hum you are experiencing. When I had my single amp system, there was no hum. 2 amps, and I got a hum. Both systtems used the same grounding point.

 

[psychotic]

Ok new grounding point, sanded, good 14x3/4 self drill washer head screw, about 8 inches away from the other ground... still humming. It seems so weird that the humming goes up in pitch with the rpms. Any other ideas????

 

[psychotic]

Ok this ground loop thing at radioshack... "Helps eliminate electrical noise and hum caused by ground loops. " What is a ground loop, how is it caused?

 

[Digger196]

did you bypass the factory amp? if not, do it. that's where i got my humming from. try that and see if that helps.

 

[psychotic]

I have no factory amp. I believe I have a few options... the fact that i used home rca cables. And the fact that the RCA cables are being ran next to the power wire. Now that i know my problem is called a ground loop, the search turned up a lot of info. What do you guys think?

 

[Robb]

I would think that your 96 XLT does have an external amp. Have you proven that it doesn't? Home RCAs are ok. RCAs directly next to power cables can be a problem.

Robb

 

[psychotic]

No, if my xlt had a factory amp, Circuit city was going to charge me a lot more to install my HU. Circuit city installed the RCA wires of my old amp running along with the power wire.... is this bad of them? Simply ok because the other power wire was only 8 g and this one is 4g?

 

[ShadowA2J]

Definately move your RCA's. They will very easily pick up a hum from being run next to your power wire. When you say home RCA's, do you mean good ones like Monster, or like the ones that come with a new DVD player?

 

[psychotic]

i mean like $30 - 40 for 20ft of RCA didn't seem worth it when the others were only 15. Didn't think it'd be that different. They are just black RCA cables... gold tips but nothin special

 

[ShadowA2J]

So they are the cheap ones. The only reason why that is bad in a car is because of the very little sheilding they have. I would try moving them, and you might just get lucky and not have to buy new ones. I also know of an engine noise eliminater that goes inline with your RCA's that might solve your problem. You can get it here: http://www.crutchfield.com/cgi-bin/S-Wmp1ubUhyGt/ProdView.asp?s=0&c=11&g=780&I=127SNI1&o=m&a=0 It's only $15, so that would save you a little more than buying those $40 RCA's.

 

[jasongrooms]

I agree with everyone, Ground loop, and better RCA's. Get those and your hmmmmmmmmm will be gone :redexp: