Trying to get white noise out of my tweeters...tried everything...

[cleanerupper 10+ year member]

I'm having a problem with a constant white noise (soft static noise) in the tweeters for my Boston Pro60s. The sound is always present when my amp is on. The amp is a JL 300/4.

The noise stays constant and doesn't vary with engine speed. The noise does not get louder when I turn the volume up.

I've tried finding the source of the noise by the following methods, and nothing seems to affect it:

-Switching out the JL 300/4 with another amp

-Trying a different set of RCA's

-Trying a different head unit

-Plugging the tweeter wires directly into the amp (Not using the passive crossover).

-Regrounding the amp

-Regrounding the head unit

The ONLY time the noise stops is when I unplug the RCA's from the amp. Does anyone have any idea what could be the issue here?

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[Etac 10+ year member]

i'm by no means an expert.. but did you check the battery/chassias ground for rust/connection?

 

[GrnEydDvl 10+ year member]

Where are your gains set and how did you go about choosing where to set them?

 

[Eugenics 5,000+ posts]

reinstall windows

 

[cleanerupper 10+ year member]

Well it's a brand new car so I doubt there's any rust on the battery to chassis ground. Anywho, I've checked it several times and it looks to be a good connection.

Gains are set at a little below halfway. This is far within the safe voltage range that I checked with a DMM. I used the JL Audio tutorial for setting my gains.

 

[squeak9798 5,000+ posts]

Unplug the RCA's from your HU but leave them plugged into the amplifier.

If the noise goes away, then the likely source is your headunit.

If the noise is still there, then you are getting induced noise somewhere...possibly from having the RCA's routed near a "noisy" vehicle component.

 

[GrnEydDvl 10+ year member]

Well it's a brand new car so I doubt there's any rust on the battery to chassis ground. Anywho, I've checked it several times and it looks to be a good connection.
Gains are set at a little below halfway. This is far within the safe voltage range that I checked with a DMM. I used the JL Audio tutorial for setting my gains.

Do you have the amp bridged? The way JL wants the 300/4's to work with bridging is a little odd. You have to use all 4 channels of inputs even if you are bridging it to two channels.

If you have two pairs of outs on your deck for the HP, try using two runs of RCAs for that amp. I found when you use one RCA cable and Y-splitters to achieve 4 channels of inputs (as the manual indicates), you end up having to crank the gains and noise gets amplified.

If you have the outputs on your deck and the extra cable it may be wort a shot. Make sure to reset the gains after you add the extra cable.

 

[cleanerupper 10+ year member]

Unplug the RCA's from your HU but leave them plugged into the amplifier.
If the noise goes away, then the likely source is your headunit.

If the noise is still there, then you are getting induced noise somewhere...possibly from having the RCA's routed near a "noisy" vehicle component.

Okay I'll go ahead and give that a try. It really must be induced noise since I've had 2 head units do exactly the same thing (Kenwood x990 and my current Eclipse CD7000).

If it is induced noise, are you sure it will still induce itself with one end of the RCA unplugged?

 

[cleanerupper 10+ year member]

Do you have the amp bridged? The way JL wants the 300/4's to work with bridging is a little odd. You have to use all 4 channels of inputs even if you are bridging it to two channels.
If you have two pairs of outs on your deck for the HP, try using two runs of RCAs for that amp. I found when you use one RCA cable and Y-splitters to achieve 4 channels of inputs (as the manual indicates), you end up having to crank the gains and noise gets amplified.

If you have the outputs on your deck and the extra cable it may be wort a shot. Make sure to reset the gains after you add the extra cable.

Nope, I'm bi-wiring...using all 4 channels. 2 channels for tweeters and 2 channels for mids. My current head unit (Eclipse CD7000) allows me to use the "Front" RCA's for highs and the "Rear" RCA's for mids.

 

[cleanerupper 10+ year member]

Okay so I unplugged the end of the RCA's from the head unit today the noise is still presenting itself.

So, according to Squeak, it must be interference in the wiring somewhere. The thing is though, I've already tried a different set of RCA's just ran straight through my car and they do the same thing.

What else could it be? Could it be a combination of bad signal and bad amplifier?

 

[phyphoestilic 5,000+ posts]

Okay so I unplugged the end of the RCA's from the head unit today the noise is still presenting itself.
So, according to Squeak, it must be interference in the wiring somewhere. The thing is though, I've already tried a different set of RCA's just ran straight through my car and they do the same thing.

What else could it be? Could it be a combination of bad signal and bad amplifier?

maybe interferience the speaker wires? Did u try hooking up the tweeters directly out of the car with the amp, so the wire's arnt running thro the car.

 

[bballrrt06 10+ year member]

reinstall windows

ahaha lol.