# Stock System Sounds Better Than My New One



## fast_kozak (May 18, 2007)

Ok, I know this is dumb, but it's happend to me. I have a 2004 Spec V, and it came with the RF Package. It was good, not great, but I chose to change. I did the following:

Infinity Kappa Components 6 1/2 in the front w/tweeters

Infinity Kappa 2/way 6 1/2 in the back

Rockford Fosgate Punch P3DS410 Sub with homemade enclosure

Rockford Fosgate Power1000 Amp

Pioneer DEH-6800P Head Unit

We installed the system using a 0 gauge wire for power, 1 gauge for ground, 12 gauge for speakers (all of them), and a 14 gauge for the remote switch. 

So now I've got this high pitched whinning sound comming through my system every time my engine revs. I can't go past the 35level on the HU otherwise my speakers start to crackle and get distorted. There doesn't seem to be ANYWHERE NEAR the base I get with cds when I listen to the radio. And lastly, I haven't the slightest clue what's going on.

PLEASE, all you audio guru's out there. Help me out.


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## jtandori (Jul 1, 2007)

I'm not a car audio expert but I know enough about audio in general to suggest a possible grounding problem. 

It seems that what you describe as a whining noise may well be the alternator's electrical noise, and one possible path to get the noise into the system is through a ground path. 

By ground problem I'm not suggesting a bad (as an weak or not properly conducting the current) ground connection, I'm sure you did all the connections properly, but I think mostly at a ground loop in which your return audio signal has a common path with the alternator's current (i.e. through a part of the chassis). 

I see for instance that you used 0 gauge for power and 1 gauge for ground. May I ask why? The same amount of current that flows from the power (+) must return into ground, which suggests using the same gauge for both power and ground, unless... you planned to divert some of the return current through the chassis and you thought you may no longer need the same gauge for ground since some of the current will flow through the chassis. If this is what you did, than I think you should revise your grounding scheme because the moment heavy currents start flowing through the chassis you lost control of the ground path. 

To make it short, you have to be in total control of the ground path and understand how the current is flowing so that ground loops are avoided. Sometimes this is not possible and you may need to use ground breakers (or ground isolators). 

The speakers starting to crackle at high volume make me think of some oscillations that could be again caused by ground loops. If for whatever reason the ground wire from your amplifier is sharing a common path with the ground from the radio's or CD's output signal, you can have a serious oscillation problem (can only be seen with a scope but you can definitely hear it as "crackling" noise). Be very careful here, if there is indeed a high frequency oscillation (amp becoming unstable) you can easily blow the amplifier!


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## fast_kozak (May 18, 2007)

Thank you for your imput. 

The reason why I chose to do everything the way it was done, was because I am in no sense knowledged in car audio, and my friend who's an electrical engineer suggested this to me. He too has done a few car audio systems on his own, so I trusted him.

My grounds are as follows; 1) at the head unit, a 12 gauge wire connected to a bolt in the chassis. 2) the one from my amp is connected to a bolt (we dremmeled the paint away) that's found under a bracket for the rear seats. 

Does this help is your personal diagnosis? Is it done right?


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## jtandori (Jul 1, 2007)

If I would do the grounding I would make a "star" ground scheme (all grounds going to a single point) and the star center point would be straight at the battery's negative post. Not an easy thing to do on a car though, since the equipment we may use (head, amp) may have a metal enclosure which is already connected to ground and during installation one may touch different parts of the car's chassis with the head or amplifier's enclosure, hence creating another path to ground. The ground from the radio's antenna coax cable is another typical case where you could provide the head's enclosure with another ground point through the coax cable in some cars. 

So far I see you have two ground points, one at the head and the other one at the amp, which basically means you created a ground loop through the chassis. 

Assuming that the only ground for the head is the one you connected through the 12 gauge, try disconnecting the head's ground from the bolt in the chassis, and just for the purpose of testing, run the head ground wire (gauge 12) at the rear where the amp is connected to the dremmel'd paint bolt. You would so create a star ground, with two wires going from the same point (bracket for the seat bolt) to the head and to the amp. This is not ideal, since you still carry most of the current through the chassis and not through a wire, but it will help in pinpointing a loop problem. 
Remember, this won't work if the head has any other ground connections (e.g. head enclosure is made of metal and is attached with bolts to the car's chassis, radio antenna has a ground connected at the rear, etc.).


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## JNCoRacer (Apr 18, 2003)

What do you have the remote wire connected to? When I boughtmy 96 Maxima 5 years ago someone had tied the remote wire to the 12v power port (aka cigarette lighter) Sounded like ass and I had this horrible whinning noise as well. Also Its a good idea to run your power and remote wires on one side of the car and your audio wires on the other. Keeps the interference down.


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## fast_kozak (May 18, 2007)

The remote wire is connected from the head unit, runs down the right side on the car (passenger side) and goes straight to the amp.
My power cable is on the driver's side, and RCA and stereo wires are along the passenger side. They're separated.


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## fast_kozak (May 18, 2007)

Thanks for that star suggestion. I'll give it a try tomorrow. Is there something else that's wrong that I did with the setup?


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## fast_kozak (May 18, 2007)

Hey, thanks for writting everyone. 

Good news; problem's been fixed. It was a matter of tunning, and speakers having too much gain. System sounds soo bad-ass now, and my bass is at 0 on the HU. It's like I don't need to crank it up. 

Anyways, this is the end of this thread. Thanks!


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