I looked in to the same. I stopped after realizing the amp in the all-in-one system would need to be beefed up with another external amplifier.
Depending on the year of your zinger, You most likely have these speakers (Crutchfield.com carries them)
6-1/2" speaker for RVs
- single 6-1/2" speaker
- paper woofer with paper surround
- frequency response 130-5,000 Hz
- recommended power 30 watts RMS
- 45 watts peak power handling
- sensitivity 89 dB
- top-mount depth 1-1/2"
- warranty: 1 year
The extraordinary think mounting depth is hard to find in a good set of replacement speakers.
Better speakers require more watts than what the factory head unit puts out. My 2013 300BH has this unit:
- Maximum Current Consumption: 9 amps
- Total Continuous Power Output: 50 watts
- Load Impedance: 4Ω (4Ω-8Ω allowable)
- THD: typical 0.02%; maximum 0.3%
- Video Output Level: 1.0Vp-p +/-0.2V 75Ω
Anyone out there get these head units (or similar) to drive a good set of aftermarket speakers and sound better than the factories, I'd love to know. The numbers on paper don't appear to be an improvement.
There are cheap after market amps you can wire inline, but I didnt want to mess with it before our season last year. Thinking about making the change.