Thread: Soundcard, FM Modulator, Onboard Audio

I have an Epia M10000 running through a 3.5mm extension cable, to a ground loop isolator, to an FM modulator to my head unit and the sound sucks. I'm trying to diagnose where the issue is and/or take parts out of the equation. Basically the sound level is very low and it crackles.

If I plug my iPod into the FM modulator the sound is fine, so the modulator is ok.

If I run from the PC through RCA to the modulator the volumne level is ok but it still crackles (I need some more connectors to put the ground loop isolator into this config).

So, I suspect the long 3.5mm extension sucks to start with but it isn't the only issue, it also seems the on board audio leaves a lot to be desired, would you agree or are people generally ok with the quality?

My options as I see them:

A real aux-in is out of the question, simply isn't an option in my car and the head unit cannot be replaced - don't ask, please!

Soundblastre PCI - to try this I need to get a riser but the wiring would still need to run the same way, is it likely to be a big improvement in quality?

Soundblaster USB - If I go this route I could put the sound card near the head unit, is a USB cable less prone to interference and loss than an audio cable? I would have thought so. The USB cable would be about 8' long.

Recable and use the onboard audio - still dubious as to if this would help or not. If I have a 3.5mm to RCA adaptor by the PC, run RCA to the head unit and in to the FM Modulator is this likely to improve things? Would using a crappy cable introduce "crackle" into the signal? Could this be because the audio cable passes near the battery and other power cables?

Any help, suggetsions or questions are most welcome. I favor the Soundblaster USB option as my next try, any comments good or bad on that approach?

Chris.