Subs...ugh

[91lxdreamer]

In my civic, I have two mtx 6000 series 12" subs powered by a kenwood 1000 watt amp. One of my subs is grounded out, so I have it completely disconnected. The one sub I do have connected is bridged. My question is this: When I start my car, and my stereo turns on, my amp comes on, and immediately, my subs have a whine first of all, but thats more in the background. The sub also has a rumble in it, and it goes according to my rpm's, up to about 2000 rpm's. Then it dies off. I can really only hear it at low volume levels, however, it stays the same, like if I have it on volume 1, it will be as loud as if I had it on volume 50, I just wouldnt be able to hear it since everything else would be so loud. What is causing it to make all this noise? Is it not grounded right or is something else wrong...my amp...wiring...rc cables...etc? I need help, and this is the only place I knew to come.

[Wiseguy]

its just a little interference from your alt.

farad capacitors can reduce even eliminate that (not just for an extra boost of power), ever consider one?

other than that its normal, i use to have the same rumble

[Streetwise]

A cap will not reduce engine noise, ground loops, or alternator whine. A cap is basically an extra source of 12 volts like a battery. And in all reality they bebefit mids and highs more then they do subs. My guess is, as with any noisy system, it could be a number of things.
1- A loose ground, or a bad ground.
2- The ground wire is not as big as the power cable.
3- The ground is too long. The shorter the better.
4- Your signal cables are not shielded enough. Get good ones.
5- Your power and signal cables are run on the same side of the car. Although this may easier, run the power down the same side as the battery and the signal cables down the opposite.
6- Sometimes the equiptment is not up to par and can add noise.

If your system pops when you turn it on or hit the brakes, etc. Then there is something that can be improoved. Unless the song you're playing has bass drops that sound like "rumbles," it is not normal.

[PaulD]

Originally posted by Streetwise
A cap will not reduce engine noise, ground loops, or alternator whine. (SOMETIMES IT CAN, A CAP IS OFTEN USED AS A FILTER IN ELECTRONICS - BUT EACH CAP USUALLY ONLY WORKS FOR A CERTAIN SMALL BAND OF FREQUENCIES). A cap is basically an extra source of 12 volts like a battery. (CAPS ARE NOT A SOURCE OF ENERGY, THEY JUST STORE IT). And in all reality they bebefit mids and highs more then they do subs. My guess is, as with any noisy system, it could be a number of things.
1- A loose ground, or a bad ground.
2- The ground wire is not as big as the power cable.
WILL NOT FIX ALT NOISE

3- The ground is too long. The shorter the better.
WON'T FIX THE PROBLEM EITHER

4- Your signal cables are not shielded enough. Get good ones.
SHIELDING ONLY EFFECTS FREQUENCIES ABOVE 1 MHz - WORTHLESS FOR AUDIO. IN FACT, THE SHIELD OFTEN ACTS AS AN ANTENNA FOR NOISE

5- Your power and signal cables are run on the same side of the car. Although this may easier, run the power down the same side as the battery and the signal cables down the opposite.
OH GOD, PLEASE ... NOT THAT ONE AGAIN

6- Sometimes the equiptment is not up to par and can add noise.
A POSSIBILITY THERE

If your system pops when you turn it on or hit the brakes, etc. Then there is something that can be improoved. Unless the song you're playing has bass drops that sound like "rumbles," it is not normal.

From the description of your problem, I would guess you have a bad component (ore one that is poorly grounded) or an RCA type cable that is being invaded by noise.

[91lxdreamer]

I cut off some of my ground, and rerouted it to the bottom of my trunk. I drilled a hole in my trunk, and sanded it all down to the bare metal. So yeah, to my knowledge, the rumble is gone, unless it just got quieter. I forgot about this tho, in my 5 1/4 on the back deck, they have the engine whine in them too, but it got drowned in the sub rumble that I forgot...lol. Oh well...I guess it'll have to do, its not that loud so I can deal.

[Streetwise]

Well, hey that's cool. I'm glad making the ground shorter helped some.
Also, that's funny because I was just thinking I forgot to mention sand off any paint on the ground. A little trick if you have four guage or heavier, If you use the crimp 4 gauge ring terminal. Sand the paint a little, screw down the ground nice and tight, then if there's room, run a self tapper inbetween the bolt and the crimped point. That'll hold it.
And about the 5 1/4, are they amped too? If so, and you have inexpensive cables, try to run it on opposite ends, it may help a little more. Not much for subs, but if you amp mids and highs, they are generally noiser, give it a shot, at least you know.



The force is strong in this one