I've been playing music more lately in my Prius C. Many CDs are not that loud (or I should I say not loud enough for my liking) when turned up to the max. I wouldn't want to upgrade the system. I want to leave it stock and untampered with. But I have MP3 albums on flash drives that plug into the USB port and many of them sound quite amazing, IMHO. I have a bunch of surf music by Los Straightjackets and other bands. Tell me, if I park the car and listen to the MP3s, should I leave the motor on or off? I don't want to run down one of my batteries.
Keep the car in READY, not ACCESSORY or ON, so the engine can run as needed to recharge the HV battery, and the DC-DC converter can keep the auxiliary (12-volt) battery charged. See the Owner’s Manual (PDF), page 169.
Agreed. The stock system isn’t bad at all. I did swap out the driver’s side speaker last year. My issue with the sound quality was minor: I felt like it had good highs and lows, but weak mids. I actually did both front speakers and it was a downgrade, but one speaker added a bit more midrange and balance to the sound. I think some models only have front speakers, which would probably make for a different experience. But yeah, just keep the car on. Playing music for hours without being in ready mode could kill your 12v. A Prius can be on for days and it won’t hurt it.
. I don’t have any suggestions for your sound system but I commend your good taste in music. Los Straitjackets are excellent. Ever listen to the Aqua Velvets?