vetteflame79

i have a 79 c3 and no matter what i do to it i get a high pitched sound from the speakers that gets louder with the rpm's.
PLEASE HELP :banghead:

Metal Wulf

give us some more details... like... where/how is it wired. speakers, HU, etc. also what kind of ignition/wires/etc. :cheers:

vettfixr

Been there, done that, bought the T-shirt, and wore holes in it. You're getting alternator whine. You need to put a filter on the alternator line. If I remember correctly I got mine from Ecklers but looking at their site they don't have the model I bought. They have this instead: http://www.ecklers.com/product.asp?d...J6N4PVWDEH0GJ5
I also use another for the head unit that I got from Jegs. It's made by ACCEL and does a good job also. Here's the link: http://www.jegs.com/cgi-bin/ncommerc...73&prmenbr=361
You're probably going to get a lot of posts telling you that noise can be eliminated by making sure all the components are grounded correctly. This is true but I did just about everything except encase my car in lead and I couldn't remove the noise until I used these filters. I even had a new alternator and it still did the same thing. Basically what is happening is that you are getting noise in the power line. Autos use direct current for power. What happens is that the power lines get some AC (alternating current) components in the line which is amplified by the electronics of the stereo. These filters allow the AC to go to ground. You will see that they have three wires. Usually the red goes on the power line and the blue goes to the component. The black line goes to ground and grounds the noise. Give them a try before you loose any more religion.

Yellow79

that high pitched tone happens to be an alternator whine. play the stereo with the motor off and it will dissapear. what happened is that when you ran power line(hopefully a short one) to your amp, it ran too close to your speaker wire and now the current running through the power wire to the amp is inducing a "charge" in the speaker wire that translates to your speakers as a whine. reposition your wiring, and if a power wire HAS to cross a speaker wire then make sure they cross at a 90 degree angle. if they run side by side for even a short distance you will induce a whine. good luck :smash:

Yellow79

lol vetfixr beat me to the punch, evidently while i was typing the last post. the whine might be eliminated with the filter he speaks of, although out of two vehicles where i had a problem with it the filter didnt work in either. different brands maybe? i had a scosche(sp) and it was worthless

zwede

I've had no luck with filters. To get rid of whine and noise there are 2 twings that are absolutely essential:

1. A GOOD amp. Cheap amps will almost always whine. I'm using a Rockford amp. My rule of thumb: If the amp is less than $300, it's probably no good.

2. Wiring. Run a heavy gauge (8 gauge is good) directly to the battery. The ground wire has to be the same gauge and go to the frame (NOT the battery). Use high quality RCA cables to the headunit, NOT speaker wires.

I have no filters on my car and there is no alternator or ignition noise.

Bearcat

Keep your ground lead as short as possible. Use a filter. If it doesn't work, go get a better filter. Make sure your speaker wires don't run parallel to a power lead, or any lead that carries current. Switch over to shielded spark plug wires with a grounded sheath, or at least noise suppression wires.

Another thing that I've seen do this is a voltage regulator going bad. That sets up a pulsating DC that pulsates with engine rpm, and your stereo does not get a good DC voltage level. That too can inject noise. But that's the easiest to check. Take it to an auto electric place and have them test it. If you have the older C3, it's a separate voltage regulator.

The older C3's had very elaborate shielding around the wires and a large capacitor on everything. This was for a reason. Grounding things in a fiberglass car introduces some unique problems. You have to verify all your grounds. Keep them short and heavy gauge. That will help.

mrvette

ALL of the coments are correct, but zwede here nailed it right on...cheap amps do not work well....it's the internal power supply has come directly off the 12 volt source with no interleaving real power supply conversion of voltage....which by it's nature will eliminate that power whine....it IS a/c components on the 12 volt line...for sure....
putting inductance/choke in the line and caps to ground can help a LOT, depending on some variables....BUT it can also make the amp unstable and basically un usable.....
sometimes it not the cost of the amp that's critical....years ago I had a damn good amp I wish I"d kept....but it was only 100 bux....it had a nice switched mode power supply and NO whine....

a good head end is requisite also...cheap one's will have the 'problem'....

GENE

stickben

Try a ground loop isolator, I think radio shack sells them for $10-$15

TJKirby82CE

OK let me get this straight. Same problem.....run the filter inline with the power line for the amp...I have 8 gauge wire supplying power to teh amp... I run this filter in line with its 18 gauge wire...???Power goes from the battery through this filter to my amp? it seems like they would make a filter with a larger gauge wire if this were its intended purpose.

vssii58

Had the same problem when I installed a amp in mine. Go to radio shack and get a noise filter for the radio (around 15.00). Place it in line with the amp and the raido. Red to red, blk to blk and bingo it's gone :thumbs:

mrvette

TJK, that is a problem allright....the wire in those Rat Shack chokes is too thin for anything over about 15 watts/channel RMS.....most likely the amp will become unstable, and break up or oscillate on it's own....

I think the comments of other amps being better design, and most likely higher cost, is the one to pay attention to....might TRY another amp at say CCity or BBuy.....dunno what their policies are on that stuff....

GENE