coldshadow73

Ok, I do car audio installation in my home town, not a business, just friends cars and such , but i am fairly good with car audio. Today my friend said his subs are acting funny. I go over and check it out, they just keep holding this totally different beat, its not even close to what the music is playing, it just goes, thump, thump, thump regardless of whats playing or anything. I about because the same thing happened to my friends car, he sold it but we never figured out why it was doing this. I checked all the wires, i put my amp in the car, i changed the RCA'S, im just lost at this point. Its happened twice now so im sure someone has had this happen to them, please help me!
Thanks guys,
tyler

92zed34

iTrader: (4)

Any change if the car is running and not running? or is it the same?

coldshadow73

no, regardless, sometimes its a little different pattern, but the same thing, the second the head unit turns on, even before the song starts, it just starts bumping loud, in a pattern, but no were near what the song is. I put my head up to the subs, very, very faintly, i can hear the song in the subs.
im so confused, im sure their an answer, i also pulled the positive terminal off the car and took the head unit out for 10mins, still same results.

twistedsickness

Only think 2 to thinking i can think of 1 are the RCA and the main power wire running along each other? and broken RCA's and you can always try setting your deck back to default and see what happends. ok thats 3

Otherwise good luck I have no idea.
always try google it

jj_spike

I just went through something very similar. I had a problem where my new MMats D1100.1 was outputting a faint "farting" sound. I tried building my own twisted pair RCA and re-routed power cables. I did manage to eliminate the slight bit of engine noise that I had but it did not clear the strange output. After a bit of testing, I found that this happened only after the amp warmed up after 3 to 5 minutes.

In order to eliminate signal and power feeds, I disconnected the the input and supplied input from my iPod. The problem was still present. I figured that the amps internal crossover was allowing frequencies above 250 Hz to pass. I figure that since this is a class D amp, it is not able to properly reproduce higher frequencies. The small amount of higher frequency that was allowed to pass was being output as a "farting" noise due to class D operational characteristics. Someone jump in and correct me if I am wrong.

My local MMats dealer (Stereo 1) quickly exchanged the amp without any issues. Kudos to them! The new amp did not have this issue.

Try a different input source such as an iPod in order to rule out the HU and associated components.

JJ