Whoa!!!! bout to take a hammer to the radio.

[eddie1]

ok listen to this guys......

i have a jesen vm9312hd head unit with mach audio bypassed and wired my self, amp, 2 12's...........

The problem is the f***ing subs run with the speed of the engine. so when i idle the subs run even when turned off buy the head unit. If i disconnect the RCA cable it turns off tho, if i diconnectthe ground it turns off.

The trouble is it only does it when the car is running, if i use anything eletric say windows the subs will thump every time i hit the button.

I've checked ALL wires to amp and radio all fine, I've replaced both RCA cable and y adapter.........

Not a eltrician but im about 100% sure it a ground problem and i have no idea were to start. BUT likei said it only does when the cars is running, i can turn the key on and it won't do it.

Keep in mind everything less than half a year old, never been wet, never left windows down over night, nothing to get any water or moisture damage

ANY HELP?

[19Delta]

You need a Noise Filter. Here's a link to a few:

Noise Filters | 12 Volt Noise Filters at Sonic Electronix

[eddie1]

i knew that but all they do is sapress the problem and lower the signal output.....

there are no power wires within 1 foot of the the RCA cables so i don't see what the problem is.

[19Delta]

Try this then.

http://forum.sounddomain.com/ubbthre...e/1#Post341805

[OsirisGuy]

Did you run power and audio wires on opposite sides of the car? It sounds like alternator whine, or a bad ground. Is your ground wire short? Equal in gauge size? Is the amp grounded to bare metal?

[ThaWill]

What kind of RCA cables are you running? Are they shielded? What kind of amp do you have? Did you buy it at the dollar store? If I had to guess i'd say ground, but if you bought some cheapy equipment you might never get it fixed.

[19Delta]

I would seriously check the RCA's, they might be shitty. Get a set of stingers.

[OsirisGuy]

Or Rockford Fosgate or Monster for car audio are my top two recommendations.

[eddie1]

they are on oppisite sides of the car.

the rca cables are from best buy....they are brand new the old ones did it two.

the trouble jsut came outta no wear one time when i started the car......

I'm guessing it a ground were should i start?

the amp is a lanzar amp and yes it grounded to a bolt in the trunk.....should i fix this?

[OsirisGuy]

Does the Ground bolt have bare metal? Does the Ground cable have an eyelet attached that the bolt goes through? I would make sure that there is an eyelet on the end, preferrably a nicer one you'd pick up separately, give it a good crimp and solder. Then clean up the bolt and expose the bare metal and both the bolt and around the hole the bolt goes into. You want that ground as an extension of the car's body.

Also check your connections at the amp, make sure it is clean and tidy and you don't have any stray wires from the power or ground cable touching your RCA connections or out puts, all for instance.

[eddie1]

the rca calbe are the oppisite side of the amp from the power wires.......and with the ground you were talking about im not fallowing can you give a picture

[OsirisGuy]

How's this?

I know, my MS Paint art work is uber fabulous, and I'm the Degas of MS Paint.

[19Delta]

Woah...very nice.

[eddie1]

ok well just relocated my ground to the back seat bent anchor and the noise still presists.

now what?

[silverstangboy]

you clean the connection to bare metal as suggested? it will make a big difference.

also, take a look at the connections at the head unit as well.
Jensen isn't the best thing on the market either and from your description of the sub not making the noise after the RCA is disconnected from the head unit makes it sound like to me that the head unit is generating the noise (regardless of turned on or off its still possible) experiment with the wiring up front..

[eddie1]

done that.....reconneted all wires and still problem..........after i regrounded the wire the subs do sound alot louder when crnked up......but regardless the noise is still there sadly

[OsirisGuy]

You are getting electrical interference somewhere.

If, as you give it gas, you start to hear a whine - specifically alternator whine, then the power leads are leaking into the audio lines.

If you are getting a thump or a hum then the ground, or power is leaking out or into somewhere. Check your sub wire connections, perhaps?

But it really sounds like the amp is looking for a place to ground other than the ground lead - thus it is grounding into the RCAs and audio wires. This could be a reason for the thumping to when you use something electrical.

As stated before, Jenson can sometimes cause problems. How did you hook everything up? Did you use any other means of power and grounding? Or did you use the "correct" connections?

[eddie1]

all wires are connected with plastic crimp connectors......the amp is sitting on a wood cut out of the floor of the trunk so it not touching metal at all.

I'll go around and reconnect all conection to the amp again....but like i said it will only make noise when car is running and some time it won't make any noise until i rev the pony up.

[OsirisGuy]

So you won't get any sound when the car is just running in accessory?

Did you run the power straight from the alternator? Perhaps somehow the amp is drawing its power from the alternator and not the battery. Your battery may be going bad.

[upton7]

I had that problem then i bought a new head unit and it went away

[eddie1]

wow ha my battery is bad so im guessing that the problem? if it is wow i sorry for the toruble guys.

[OsirisGuy]

Try replacing the battery and see if it helps any bit. No trouble my man, troubleshooting can just be a bitch when you can't be there and actually test your theories.

Let us know if it works.