Wierd Problem w/ Sub or Amp?!

[Rate4 10+ year member]

I have a rockford fosgate 900w mono amp pushing a 12" MTX Thunder 6000 series. When i crank my truck, or even turn the key back to listen to some tunes, the sub keeps a constant beat that sounds like a helicopter, even if the volume is on 1 it keeps that loud constant beat and has a funny smell. It does it when the +Db is on 8 and 12, when its on 4 its not as noticable but still does it very slightly. Whats the deal? I switch amps and still does it on higher +Db ratings.

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[MisterGrubbs 5,000+ posts]

Because the loudness is more apparent when you turn it up.

Check grounds and RCA's.

 

[Rate4 10+ year member]

The beating is the same volume even when i turn the stereo up, in between deeper beats it still does the helicopter noise, the rca's i think are fine, the ground is fine too i think, but the smell is wierd and im just wondering whats up. I can check the ground later on though just in case.

 

[TreyE 10+ year member]

engine noise?

 

[MisterGrubbs 5,000+ posts]

Tried moving your ground? I'm not too savvy on troubleshooting

 

[Rate4 10+ year member]

What? No the truck can be turned off and it does it. It's wiered, maybe the wiring is jacked up somewhere, its just annoying and the smell is awful.

 

[Rate4 10+ year member]

No not really, i guess i can though, if someone could give me a few possible causes i will go out and tinker with it a bit.

 

[CarlosV 10+ year member]

bad ground check it or relocate it, had the same issues or similar except the smell

 

[Rate4 10+ year member]

Will it cause the wierd smell? Ive had 2 setups in my truck, first one was Pioneer 10" TSW sub from walmart with a california 400w.2 bridged. It beat well and never had problems with it and this setup i have now started acting wierd after a week. Ive changed amps on it 3 times, first rockford 900w, then Jensen 220w.2 bridged, then kenwood 600w.2 bridged and the kenwood bridged pushed abot 1000w and it beat really well but them it started doing the off beat thing so i whent back to the RF amp it still did it. So you think its the ground? Ill try it in a minute and let you know, thanks for the help guys, let me know if you think of anything else.

 

[Rate4 10+ year member]

Checked ground, changed the end to a new one and still same thing. Any other ideas, the smell seems to be coming from the connector on the back of my box. Sub blown or wiring problem, its kinda getting annoying now and i need to get it sorted out soon, any help is highly appreciated.

 

[Rate4 10+ year member]

Still puzzled, i have a Pioneer stereo, if that matters, doubt it though.

 

[Realbleach 10+ year member]

pioneer you say...

take a wire, strip it and wrap it around your rca outer portion on the deck then plug the rca back into the deck ...

let me know

 

[95BlackGA 5,000+ posts]

Unhook the sub, and get a DMM and put it on the speaker outputs of the amp while the truck is on, and the stereo is on 1. See what kind of voltage you are getting from it, and report back here. Also, don't tell me you can't do it 'cause you don't have a DMM, if you want to get it fixed, you will go out and get a DMM, and check it. Also, try another speaker, doesn't have to be a sub, just see if there is that noise still.

 

[Rate4 10+ year member]

pioneer you say...
take a wire, strip it and wrap it around your rca outer portion on the deck then plug the rca back into the deck ...

let me know

Just finished doing this and it DID help, the sound is still there though but a lot quiter and seems to be a different beat now. Im using tiny *** wre to go from the amp to the sub, should it need to be beefed up?

Is a DMM an Ohm meter?

 

[Realbleach 10+ year member]

what do you mean different beat ?

if it hasn't gone away totally try take that wire you wrapped around and ground it to the chassis of the vehicle