amp whine?

Sabrewing5 · #1 10-17-2004, 01:46 PM

My rockford fosgate 6x9s have developed a high pitched whine, the speakers are powered by a rockford fosgate amp. I tried filtering the inputs for about everything, changed the inputs from my sub amp to these amps and changed the ground wires, which didn't help at all. I think it maybe the amp, something may have hit it. Anyways is there anyway that I can fix the amp or find the problem that may not be the amp? If it is the amp are there any suggestions as in type of amp or what exactly i can do. Any help would be much appeciated.

tblake · #2 10-17-2004, 04:46 PM

well, there are many things you can do to diagnose a possable amp problem. turn the amp on, leave it right where it is, and disconnect the rca's right from the amp. and see if the wining stops. If so, your rca's are recieving interference from somewhere else in your car. if thats the case, re-rout them, they are Probably really close to a power wire. If you have tried this, open the amp up, and check for any melted capicitors, or any inductors (coils of wire) that may have gotten warm, and caused a short, and also make sure that all the solder joints inside the amp are strong, and not cracked. Make sure if there is any sort of metal shield inside the amp, that it is infact in place, and soldered or screwed down properly. The reason they put these things in there is to block out any interference. What type of vehicle is this in? I know some vehicle distributors are known to make radio speakers wine. Any more questions, I will be happy to try and answer as best I can. Good luck.

Sabrewing5 · #3 10-17-2004, 06:26 PM

The vehicle it is in is a 1988 chevy s10 blazer, this amp has been in for a while now but the past few months the whine has developed. I went to AutoZone for them to check and make sure that it wasn't the alternator, like a weak or something wrong with it and as i suspected they said nothing was wrong with it. I am pretty sufficient at soldering, i didnt look inside the amp, i will do that tomorrow. If i need to get a new amp what would be a good amp jus so i can prepare, worst case. Thanks

tblake · #4 10-17-2004, 09:43 PM

I always liked rockford fosgates, Or pioneer's, I wouldnt go with a sony xplod, also dont be fooled by a 1000W amp, if thats all it says, 1000W is probably its peak, and it can only pump out 1000W for a split second. Pay closer attention to the RMS wattage. But really, there is probably nothing wrong with this amp. Did you disconnect the rca's Like I said? did the wine go away?

tblake · #5 10-18-2004, 04:08 PM

Any Luck?

Sabrewing5 · #6 10-20-2004, 03:19 PM

I took it apart last night found a couple broken solders. You know how they have like that little pointy "mountain"? well a couple of those were broken off and i could see part of the wire being exposed. I resolder those and a couple more cuz they looked kinda funny. Anyways it didnt help any. Any new suggestions?

tblake · #7 10-20-2004, 04:05 PM

Does the amp have a low pass/high pass filter? If so, maybe turn it on, and jiggle that, maybe the internal parts of the switch (or knob) are shot, or dirty, and not making a good connection anymore. I dont know what else to say, other than unsolder all the transistors, and test them, there are many things you can do, Still sounds to me like a loose connection somewhere.

Sabrewing5 · #8 10-30-2004, 07:44 PM

I think i might have thought of the problem. I havent had a chance to try it out yet cuz the POS is in the shop, damn wiring harness is messed up. Anyways could the problem be, the wires that are in the engine compartment for power could be getting to close to the spark plugs and causing this noise? any feeback would be greatly appreciated.

tblake · #9 10-30-2004, 11:28 PM

Um, if the power wire is close to spark plugs, It probably isnt the problem. Try looking closer at how the rca cable is routed. You know, I believe, but dont take me up for it, that older vehicles had some sort of thing on the distributer that would block interferance. Maybe yours isnt working. I had a friend that had his radio when on FM only, wine really bad in his 85 ford f150, It turned out being something wrong with the distributer causing it. Maybe look into that. Again, its very hard to diagnose a problem like this over the net, with out actually being hands on. Sorry I couldnt be of more assistance.

PaulD · #10 10-31-2004, 07:18 PM

that thing on the distributor is called a condenser = capacitor. It's just a filter for certain frequencies. Make sure your ground for the amp hasn't worked loose or the metal under the wire connector hasn't rusted.

CBFryman · #11 10-31-2004, 07:47 PM

That is why i always solder grounds. give a 100% better connection

Sabrewing5 · #12 12-07-2004, 04:07 PM

I took the rcas out and put some new ones down the middle of the car and the whine was still there, the whine does go away when the rcas are unplugged. Sorry i have been gone for a while.

Sl@M C@M · #13 12-09-2004, 03:18 PM

Most likely its the RCA plugs...that are connected to the amp thats bad....I've done ALOT of trial and error stuff and man have i blow alot of Sh**! As for a new amp....to me i think MTX are the bang for the buck man..they are tuff and have great sound and power...look for the class D amps....AWSOME!!

Sabrewing5 · #14 12-09-2004, 08:01 PM

So, its not the wires, not th speakers, not the HU but the RCA connectors on the amp? Hmm seems quite logical, thanks.

sr20de4evr · #15 12-09-2004, 08:09 PM

if you leave the rcas plugged into the amp, and unplug them from the headunit, what happens?

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