Well i had posted something a while back about rumbling noises, and i kinda gave up on it, but i'm back at it again....

Here's the deal. I am recieving constant rubling noises coming from my subs. Whenever anything electrical is turned on like the light blinkers, the blinker noise comes on, along with a TON of rumbling from my subwoofers. This happens even with the stereo being turned off or muted. This is NOT alternator whine.

Right now i have a 4 gauge running for power to the amp, and 4 gauge running for a ground. The power and ground are great, that is definitely not the problem. I have a proper fuse tap being used as the remote turn on for the amp. I am using the speaker level input built in to the amp, and using the wires that once powered the stock subwoofer.

The model of amp i have, supports a capacitor being plugged into the amp (has two 4 gauge inputs for a pos and neg from capacitor), so i have a 2 farad cap hooked up (Someone recommended trying to add a cap to the system to see if that helps).

Is this problem caused by the stock amplifier or the stock head unit? Did the dealer run the power, ground, and speakers too close to each other? I am replacing both within the the next month or two, but i need to narrow down the problem first, just in case one of those two are not the problem... If I can atleast be positive that it's either the amp or hu, then great i'll replace both in due time.

Can anyone shed some light on this problem for me?? If you want pictures, or more details, let me know!!

 

A. Run the cap inline with the power wire on the amp dont use whatever bullshit is hooked up to the amp or what not.

B. check to see if your rcas are on a diff side as the power wire. Stock wire enters the firewall on the left and under the driver seat runs to the center then to the back. Run the rcas on the right side.

C. what amp do you have? have u tried hooking it up with a diff one or something similar to "test" it?

 

I was hoping you'd be the one to answer .

A) We did what you suggested with the cap, and experienced no difference...
B) Since the hu is still stock, i don't have any rca's running from front to the back of the car. I am simply using the wires from the stock subwoofer and running those into the speaker level inputs on the amp.
C) Right now i have a mtx ta8502 amp. Before when i was experiencing the same issues, i was using 2 - 421D's, and experienced the exact same issues....

The only difference with the newer amp that i am using, is that im using the built in speaker level inputs on the amp, isntead of using a converter (used converter for the 421d's).

Also, for a new head unit, i was looking at this, http://www.crutchfield.com/App/Produ...3819DVD&tp=448.

So maybe the difference is between using, and not using rca's? In my '93 dodge shadow, i was using the 2 mtx 7500's dvc and the 2 421 d's without any problems, so i know when i tested that setup in my cobalt, that the hardware is still good..

thanks again man

 

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You shouldn't be using the wires from the factory sub. They are amplified already, so you are running amplified wires into another amp.

 

Go to the pre-amp side of the factory sub for your hi-level inputs.

 

does it make a difference that i have also tried tapping into the rear deck speakers as well with the same results?

nm that was dumb, so i need to find the sub wires before they hit the factory amp?

 

no using high levels regardless of amplified or not doesn't matter... and usually high level inputs direct into the amp (meaning with out the line level converter) yield the least amount of noise entering the signal

also the problem is sorta weird because thats typically a sign of a ground issue on aftermarket decks. Since your deck is stock the issue shouldn't exist (at least ive never herd of it)

 

so using the stock amp wires should not be a problem then? i just ordered that head unit so ill be running rca's from the hu to the amp so we'll see if that makes any difference bypassing the stock amp. i dunno, im again out of ideas..

one thing is we did hook my system up to a buddy's car, still using my power ground for the amp, but just hooking up the rca cabled through his car system and those problems didn't exist. I dunno if that tells you anything or not

 

Your convertor may have a bad ground or not be grounded at all.

 

not using a converter, plugs directly into the high level input on the amp

 

if everything was still in your car and all you changed was the signal (from high level in your car to rca on his) then its a problem along those lines. Ive never herd of such a problem with high level inputs other then a defective part in the amp itself. So at this point its looking like the only fix is to use the rcas so personally i wold swap the deck out but you can also try using a loc

 

Yah, i just ordered this hu, not the greatest but should do the trick for me. I hope rca's fix the problem... thanks for your help man

http://www.crutchfield.com/App/Produ...3819DVD&tp=448

Hopefully i'll find time to install it this weekend, so i'll let ya know if it fixes it or not.

 

im actually having the same problem you are... only i don't need anything electrical on for it to occur. i have 2 12" JL W3's and a JL 4000D amp setup... i have no idea whats wrong but i'v been playing with it for a little and i think it might be something with the wiring from the headunit im running. i just rewired everything last weekend except the headunit and found a new ground spot but i don't have too much time to work on it so i'll keep you posted

 

you know, now that i think of it, i have the same problem. Like if i would hit a decently sized bump, the subs would rumble.. Very interesting.... keep me posted man, as i will let you know how it works after the aftermarket install.

Hmm i guess it's really starting to sound like a ground issue now... maybe just for giggles ill try find a better ground for the stock hu to see if it makes a difference.

 

try grounding the stock hu chassis to the frame as well see if that helps

 

Where do you have the ground wire for your amp going to? Do not connect it to the negative on the battery. It should be going to chassis ground. In other words, connect it to a bolt that holds the rear seats in the car or something similar to that.

 

I've swapped out the ground location several times which has had no affect.

I've tried the first connection coming from the negative battery post, so the short 6 inch cable that mounts on that little bracket, and i have also tried a few other places as well, making sure there was no paint or material between the ground wire and the metal.. I really think it's the hu or stock amp..

 

What if you remove the high level inputs? Just go for a drive with the amp powered but no signal. Do you still get rumbling?

What about your speakers do they make noise too? (I dont know the freqency the subs are rumbling at)

I just started having a similar issue, but I am almost positive I have a grounding issue. Mine is not rumbling, but more of a popping. I will take a look at it tonight.

 

if i do not make a connection to the speaker level inputs on the amp, i don't get anything, but as soon as i plug it in, the runmbling comes. As for the speakers, i dont get the rumbling noise, just alot of static sound in the background. I'm installing my new hu this weekend so we'll see what the results are after the install... Look at this mess of wiring....

 

That is far from being a mess of wires. That is nothing compared to a full blown alarm system.

 

o i know, just what im used to. When i through a hu into my 93 shadow i had one wire harness and that was all haha, so this is a mess to me