sorry for the long post; cliffs at the bottom

so i was driving around today listening to my new (2 weeks or so since install) Rainbow CMX265 kicks powered by a new Alpine PDX4.150 (installed at the same time as speakers; was purchased before christmas). i noticed that the passenger speakers werent as loud as the driver side and it sounded like **** with a lot of extra rattles. didnt really think much of the rattles since i havnt finished deadening the door and the door panel was just hanging there. however, i faded my headunit all the way to the right and i noticed the speakers sounded horrible...really muffled, distorted, almost like they were blown. i thought wtf, those cant be blown yet, i never even played them "that" loud.

so i get home, take the door panel off, and listen. yup, still sounds bad. check the speakers ok, the connections, the crossover, etc, and everything checks out. i then go check out the amp. everything seems fine, all the wires are plugged in straight, good connections, etc.

i then switch the speaker plugs around: i take the passenger side speakers and plug them into channel 1, and the driver side speakers and plug those into channel 2. now the passenger side speakers sound great, but the driver side speakers sounded bad. now i know its not the speakers. i then flop the RCA cables around. this DOES NOT switch the symptoms like switching the plugs did. so the problem is definitely inside the amp. it seems like channel 2 is dead? and the fuses are fine.

where should i go from here? is this something I or a shop can fix? or am i going to have to ship this off?

1. recently installed Rainbow CMX265 kicks and an Alpine PDX4.150 amp
2. driving around, passenger side sounds like ****
3. get home, check speakers, wires, connections, crossover, everything fine.
4. check connections at amp, everything fine
5. i switch the passenger speakers' connector with the driver side at the amp (channel 1 into 2, 2 into 1). this made the driver side speakers sound bad, and the passenger side speakers sound great. this means the speakers are still good
6. i switch the RCA cables around. This DOES NOT switch the symptoms like step 5 did.
7. it seems like whatever is plugged into channel 2 sounds like ****
8. where do i go from here?