Hi All, Ok, I have been bashing my head against the wall all day, again, and once more request my betters show me the correct path...
Here is the problem I have. I have been trying to improve the audio quality on my color readers. It presently uses ADPCM, which is decoded and used to adjust the bandwidth on a PWM output on my PIC24, fitered by a fourth order Sallen filter into my amplifier. The audio is very scratchy, and has received very mixed reviews from users and retailers.
So, How to improve it? By experiment, I have tried to just use standard 8 bit PCM recorded audio. It does sound better, but at the end of each sample is a very noticable 'click.' I can't be absolutely sure what is causing it, but I think that it is due to the final value in the file that indicates termination is so low (0x04) that the sudden transition may be the source of the click. It isnt my turning the power amplifier on and off, I have tested that...
So, any ideas? Anyone else dealt with this sort of thing before?
Thanks, Charlie