Chipmonk mp3 Playback
16/02/08 08:44
FAQ: My mp3 recording sounds fine when I play it back on the
software that I recorded it in, but sounds like chipmonks when
downloaded as a Podcast.
The main issue is that you are playing the Podcast back using a player that can not cope with the sampling rate. If it is played in a Flash based player this is almost certain to be the problem. Flash Player only supports two sampling rates: 22050 and 44100. Most other players - including Audacity, can play tracks of different sample rates and sound totally normal.
The article here explains the issue and a possible solution by resampling (involves getting your hands dirty in the command line!):
www.boutell.com/newfaq/creating/chipmunk.html
Ideally all recording would be done at 44100 in the first place.
If the sampling rate is set at too high a value and needs to be reduced to 44100, this can be done from the track menu. See screencast video here.
The mp3 export from Audacity is rather crude and can lead the user into thinking that the file is being exported out at 44100, when it is in fact nothing of the sort.
The Lame encoder used by Audacity can have different front ends applied. These open up other features of the Lame encoder. One key one, is to force a fixed sample rate for exported mp3s.
See http://www.dors.de/razorlame/index.php for the free download for Windows.
Once you install Razerlame, click on the LAME button, choose the Audio Processing tab, and set the sample rate to 44.1 kHz. That will force the resulting mp3 to 44.1.
To be safe in future, export from Audacity as a WAV file, then encode as an mp3 externally as a second step.
The main issue is that you are playing the Podcast back using a player that can not cope with the sampling rate. If it is played in a Flash based player this is almost certain to be the problem. Flash Player only supports two sampling rates: 22050 and 44100. Most other players - including Audacity, can play tracks of different sample rates and sound totally normal.
The article here explains the issue and a possible solution by resampling (involves getting your hands dirty in the command line!):
www.boutell.com/newfaq/creating/chipmunk.html
Ideally all recording would be done at 44100 in the first place.
If the sampling rate is set at too high a value and needs to be reduced to 44100, this can be done from the track menu. See screencast video here.
The mp3 export from Audacity is rather crude and can lead the user into thinking that the file is being exported out at 44100, when it is in fact nothing of the sort.
The Lame encoder used by Audacity can have different front ends applied. These open up other features of the Lame encoder. One key one, is to force a fixed sample rate for exported mp3s.
See http://www.dors.de/razorlame/index.php for the free download for Windows.
Once you install Razerlame, click on the LAME button, choose the Audio Processing tab, and set the sample rate to 44.1 kHz. That will force the resulting mp3 to 44.1.
To be safe in future, export from Audacity as a WAV file, then encode as an mp3 externally as a second step.