niz406 wrote:MP3 part of my headunit has started playing up after 2 - 3 years ! gets too warm and songs get jumpy... yet CD playback is fine regardless ... go figure !
AHA! Now here's something I can answer for once ;)
I doubt audio cd playback is actually fine, rather it is inaudiably broken.
Whereas an mpeg stream can't lose any data at all without screeching/skipping/etc, audio cds work not exactly like but more like a vinyl record. When read in a normal audio player they'll skip like a vinyl but when read in data mode (which most mp3 players will do) it'd be like the record player has a bag of sugar on the stylus glueing it into the track groove (ignore the sound quality problem you'd have with that...). Anything bad will just get skipped over for a minute fraction of a second
Of course there are error recovery mechanisms built into the cd iso specification which lets you listen to scratched cds, but these aren't infallible and if a large concurrent section of the disc (about 5 degrees radially iirc) is unreadable then your data cd will be useless whereas an audio cd might just skip that 1/72 of a rotation, where the disc is rotating at a variable speed dependant on tracking position of between 200 and 530rpm). This is why you should clean cds in a spoke-like fashion and not rotationally
The trouble with car cd players is of course that they can overheat causing the plastic of the cd to expand which as you've discovered can alter the reflective properties of the disc causing the laser to be unable to read it. Tried wrapping up warm and belting the aircon on? ;)
An alternative I've just thought up and not tried myself yet would be to burn crap to the first half of a cd and then your mp3s to the latter half. The reason for this is as I mentioned before the drive has to spin the cd much faster when reading the inside tracks, hence just listening to stuff at the end of the disc should slow down the motor resulting in less heat production.
Winner of the 