Noise problem, very detailed

   For some time now I have been getting a hissing noise(similar to uncorrelated pink noise) coming from my MB Quart PCE216 Premium Component Speakers. I am using an Infinity Kappa 102a for my amplifier.    Nevermind my Head Unit, ground Loop Isolator, Line Level convertor and Memphis 30 Band EQ....to make things worse, the noise is still apparent with no signal input to the amp. I am able to finally cancel most noise by reducing the gain to zero, but at that point I lose midrange SQ and overall volume. I have toyed extensively with impedence matching, but haven't been able to have a low noise, good sounding sound. Right now I have about 62dB noise with a cd on pause, which is fine with my truck running, until I can hear some noise mixed with the signal at higher volumes.    I have also tried a MTX 4 channel (model ??504??) and had the same problem.    Oh yeah, the wiring going to my speakers is Tsunami, Oxygen free Twisted Pair 16gauge.    I have heard crystal clear systems at high and low volumes and would love to accomplish the same.    Any suggestions or information will be greatly appreciated.MakinWaves

The speaker wire means nothing, it will NOT exhibit the symptoms to which you refer. Reducing the gian to minimum takes care of a major portion of it? Of course it will... 62dB? That is normal everyday background noise... Talking is 70dB. If you short the INPUTS, is the noise still there? If so it is the amp... I looked up the specs on that amp, and it is 8 years old, and didn't have a really good S/N ration when it was new... (96dB - <shudder> - amps of today exhibit noise figures an order of magnitude better than that, my Eclipse 34230 is specified at 105dB, and each 3dB is a DOUBLING of useable output referenced to the noise) I expect the component values INSIDE the unit have drifted a bit, and this is very likely what is causing your noise issue. Try the shorting of the input, (make sure you are shorting the INPUT! I won't be held responsible if you fry your amp by shorting the outputs...) and see if that is it. If the noise remains, then the amp has had it, and needs to go back to Harman for a tune up. (Or it could just be that that particular amp exhibits that much noise...) I think they should still do that, but it may cost more than a new amp. The MTX is not much better an amplifier if you are trying to use it as a noise reference.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I had this type of problem on my room mates car before. It ended up being interference through the crossover. Try moving the crossover for the speakers, you know, the passive one, and see if that fixs the problemdouble-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

That was going to be my advice as well, right after trying the muting plugs.Top Secret, I can tell you but then my wife will kill me.

   Thanks for the pointers....This Wed. I am off work so I should have some time to check things over...if needed I will drive to the nearby car audio shop if I need a new amp, or I might struggle with isolating the crossovers, cause I don't know if I can find a new location too easily.    Tonight I tried moving the Line Driver and that alone was an ordeal to find a new location closer to my amp...it was tucked away under the dash. I was informed that I should place it after the EQ and just before the amp because the EQ was only designed for 5v input.MakinWaves

     Just so everyone can hear the results...     After putting in a new amplifier(fixed the #1 problem) and properly adjusting the impedence levels (primarily on my eq) I was able to decrease the noise level to an all new low. I can begin to hear it with the windows up and the truck running only with the volume above about 93dB. Otherwise it is only detectable with poor cds.      Thanks to everyone who helped me. Sincerely, "Makin Waves" NathanMakinWaves