Rookie Error:
Source Level Adjustment!
So apparently the Pioneer I have simply puts out less juice when connected to pandora from my iphone. For some reason this just never occurred to me, so I finally burned a few audio files at higher bit rates to a SanDisk USB drive, then plugged that sucker in, and it's like BAM, here's like DOUBLE the volume!
So this has cured a lot of but not all of the bass shortcomings. Basically I need to bump up the source level on certain inputs like when using pandora/iphone.
I now have the AWESOME rattle (never ending battle) in the drivers side door, so it's def playing louder without needing to go into the high 30's on the volume