I have an 06 24RL.
Other then going into the back of it and re-wiring the speakers so Left is Left/Center is Center etc. etc. mine has always worked very well.
I also adjust the volume levels for the speakers, now the surround sounds better then it did initially.
The 5th also has the exterior speakers, I like them but do not use them a whole bunch. Silly part is that one speaker is blocked when the door is left open, oh well.
07- Classic 2500 LT CC 4x4 SB Duramax/Ally
13-320RLT Crusader TE
Reese 16K Kwik Slide/Prodigy brake contoller