'93 Radio fades when Accelerating

[AchromicSkin]

Hey guys, so I installed a Pioneer Head unit, amp and sub yesterday. All was good on the 45 min drive afterward. Then when I go to head home, the sound is getting all "under water sounding" when I push the gas pedal. Whether I'm in 1st and taking off, or in 5th at 1500 rpms and push the gas on the freeway, it fades out, and if i start letting the gas up slowly it comes back. The harder I press the gas the more faded it gets. Its not an RPM based fade cuz i can be up at 3000 rpms but not pressing the gas much and it sounds fine, then I shift and accelerate, it fades again....I haven't rewired the + or - yet.....having stereo shop history I know this should be one of my first avenues, just havn't had the time yet to pull it back apart.
so...anyone think its a Alternator problem? I'm kinda stumped since its happening during acceleration only...any tips??

Thanks!!