Alternator Whine?

Have an amp that I've used in three separate vehichles now so I know it isnt the amp or atleast Im 99 percent sure. First was my truck, then my girls Camry, then my Jeep, then back in the truck. Both times I've used this amp in the truck it has a very loud and noticeable high pitched whining coming thru the subwoofer but not the door speakers. I can see and feel the cone moving. It gets higher pitched and louder when I rev the engine (doesnt do it at all when just the accessories are on even tho the amp is indicating that it has power) and dies down with revs so Im pretty sure its either picking up engine noise or alternator noise. The sound does is not affected by the volume of the HU or the the gain level, unlesss the gain is turned all the way off, then it stops. Didnt do this in my Jeep or the Camry.

Ground is to the body and very secure and its reading a steady 14.5 V even while playing music so im sure its not a voltage or ground issue, like I thought it was the first time I had the amp as it usually said around 13.6 when I first had it in there and the ground was not very tight and I was too lazy to fix it.

Looking for suggestions, dont want to run a ground all the way back to the battery if I dont have to, thats the most common solution I see and it doesnt always work anyway. and I've heard that there are ground loop isolators that will (maybe) fix the issue but I really dont think that it is anything to do with the ground.
My power wire is not touching my RCAs and I dont think that 4 gauge CCA will carry enough current to leak thru the thick ass insulation on the wire anyways.
Amp is a JP8 monoblock, truck is a 05 GMC Sierra with I believe the 130 amp alternator that came with the 4.3s