Problems with voice quality in mp3

[butch52]

Hi,
I'm producing a radio show using an H2 Zoom recorder connected to my computer through a USB port, using audacity. My H2 Zoom is set to a frequency of 44.1, recording as a wav. I understand the quality difference between wav and mp3 - but what I'm experiencing I think is unusually garbled speech quality (really unacceptable) when I export the audacity file as an mp3. My audacity project settings are 44100 with 32 bit float and high quality synch interpolation.
Here's my question - in order to try and improve quality while recording my voice I increased the audacity project rate from 44100 to 96000 hz - when I did that I was able to export it as a playable wav and also as an ogg, but audacity REFUSED to export it as an mp3 (got error message "audacity has encountered a problem and is shutting down). So I can't improve the quality that way, or is something else wrong here? When using a project rate of 44100, I CAN export the file as an mp3 (but with bad quality voice). The ogg files created from my voice recordings do sound substantially better than the mp3s - I just don't understand why my voice segments are so degraded while the music (imported studio music as part of the show)still sounds fine when I export the whole project as an mp3. (By the way - the reason for exporting as an mp3 is for posting to a pacifica radio access port so other stations can download it - my wav files for a two hour show are over 1GB so it's not possible to use wav. When our station downloads other programs in mp3 format the voice quality sounds absolutely fine so obviously there is a way of doing an mp3 right.....). I read on another post somebody recorded their podcast in 96000 and exported as an mp3 in 48000 but I can't figure out how to do that - when I select "export as mp3" I see no way of selecting another rate.
Any help you can give would be appreciated. Could it just be my sound card (Realtek AC97)? I know the H2 Zoom is supposed to produce studio quality result and has been used successfully by other stations, and as a wav, it does sound fine...so I don't think it's a mic issue.

[kozikowski]

In Audacity 1.3, the bit rate or quality of MP3 is set at the export step. In Audacity 1.2, it's set in preferences.

Edit > Preferences > File Formats.

Stop producing your show at wildly high bit rates. 48000, 16-bit, Stereo is the sound quality of broadcast digital television. 44100, 16-bit, Stereo is the quality of Music CDs. People have run into problems by making MP3 productions from Audacity 32-floating WAV files. Stick to 16-bit.

There are fuzzy rules for production. Avoid using MP3 music in your show. The export step will consist of making an MP3 out of another MP3. MP3, as you're finding, produces damage while it's reducing file sizes. Multiple MP3s produce great damage.

32K is the minimum MP3 rate for a mono show. 64K for stereo. Higher gets better until somewhere north of 320K, most people can't tell the difference.

Koz