• Registered: 2008-05-03
  • Posts: 15

Topic: mp3 play distortion

I have used cog for about 12 months and like it. I always use the development build.
Since I started playing mp3 files a few weeks ago I noticed that they sound distorted on my applemac.

I have established that a 1k 0dB tone needs to be reduced by at least 3dB before encoding to cure this problem. without this scale factor serious distortion occurs.

This overload distortion does not occur with any other lossy format ie. ogg/mpc/m4a The type of encoder is also irrelevant as the distortion occurs with either itunes or lame coders. Also the files that play distorted in cog play ok in all other players.

  • Registered: 2007-07-08
  • Posts: 790

Re: mp3 play distortion

Are you turning up the volume using Cog? The volume bar does go up past 100%. If you leave it alone, it defaults to 100% at startup. There's also a bit of a sticky point at the 100% marker.

Also, Cog does not currently support replaygain.

  • Registered: 2008-05-03
  • Posts: 15

Re: mp3 play distortion

The cog gain is set to its normal position ie in its indent
When I playback the test tone using any other format like flac or mpc the output sound only goes into overload distortion as the indent position is passed, However when an mp3 file is played the  distortion I identified does not reduce as the slider is lowered, it only gets even more distorted as the indent is passed going up.
The files do not have replay gain.

  • Registered: 2007-07-08
  • Posts: 790

Re: mp3 play distortion

Could you upload or send me copies of these files? cogosx (at) v spader (dot) com

  • Registered: 2008-05-03
  • Posts: 15

Re: mp3 play distortion

Flac file sent. this file has replaygain tags but the mp3 copy did not