C
Charlie E.
- Jan 1, 1970
- 0
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
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