Thank you very much Ehall! I appreciate that info very much. I mean obviously I still have the ground loop problem, I'm just filtering out that frequency and if I was using regular speakers this is not a very good solution. SOOOO ya Iv been wondering about it. I can crank the stereo and there is no humm of the trucks engine whatsoever and it sounds amazing. I wonder how the older sub will sound. I'm going to write myself a note and stick it somewhere in the truck so that one day I can fix the ground loop! like if I have another reason to pull the dash apart.... I know its not hard to pop the radio out but I'm not going to tare into just to do that.
thanks for the info I appreciate it soooooo much! I gave up on that ground loop like 3 years ago. I had no idea I even had that LPF switch at all.
CHEERS!