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distortion on exported mp3

Posted: Sun Mar 04, 2012 4:56 pm
by shinnen
Hi,
I've noticed, especially on exports of voice recitals (poetry), that there is some distortion, particularly noticeable toward the end of each word..... it's almost like I need to clear my throat. I don't hear this on the recorded piece, only on the export. Has anyone seen this, and perhaps know how to correct it?
Thanks,
..... john

Re: distortion on exported mp3

Posted: Sun Mar 04, 2012 4:58 pm
by billw58
What bit-rate are you exporting at?

-- Bill

Re: distortion on exported mp3

Posted: Sun Mar 04, 2012 8:14 pm
by shinnen
Hi Bill,
It says 'bit rate mode .... constant' 'quality ..... 128kbps' 'stereo'
...... john

Re: distortion on exported mp3

Posted: Sun Mar 04, 2012 9:29 pm
by billw58
Hmmm ... that should be sufficient for spoken word.

Could you post a short snippet illustrating the problem? If you have the original Audacity projects, choose one that has given the problem on export, select 15 -30 seconds that shows the problem in the exported MP3, the do File > Export Selection and export at the same quality as before.

-- Bill

Re: distortion on exported mp3

Posted: Sun Mar 04, 2012 11:28 pm
by shinnen
Hi Bill,
After you asked about the bit rate, I tried increasing it from 128 to 320 (the max) and the distortion disappeared. I'm not sure what the minumum is for this, but 320 fixed it for sure. Thanks for your help. If you think it need further investigation, let me know, and I'll post a clip, as you indicated.
Thanks,
...... john

Re: distortion on exported mp3

Posted: Mon Mar 05, 2012 8:17 am
by PGA
@John,
My audio work is the production of soundtracks for audio-visual sequences (involving a multi-track mix-down of music, ambient location sound and voice-over). I find 192 kbps gives a good compromise between audio quality and resulting MP3 file size.

Re: distortion on exported mp3

Posted: Mon Mar 05, 2012 2:49 pm
by shinnen
Hi PGA,
Yes..... I tried 192, after 320, and it didn't show any distortion either; so this is what I will likely use in the future. Is there a way of setting the default bitrate at other than 128. It seems like I have to change it each time I export something.
Thanks,
...... john
P.S. Just an aside. I was also having trouble with Audacity wanting to shut down after exporting. Using the correct version of lame fixed that problem.

Re: distortion on exported mp3

Posted: Mon Mar 05, 2012 3:52 pm
by PGA
shinnen wrote:Is there a way of setting the default bitrate at other than 128. It seems like I have to change it each time I export something.
John,
You shouldn't have to do that; I don't! But neither do I recall having to set anything to make it happen. Do you still have this problem after the re-install of LAME?
Peter

Re: distortion on exported mp3

Posted: Mon Mar 05, 2012 7:56 pm
by shinnen
Hi Peter,
Well ..... you're right. It seems like using the correct installation of lame fixed that problem too.
Thanks,
..... john