Over the past couple of years I’ve been using a piece of software by Magix called Audio Cleaning Lab (I’ve had it for years) to edit and reduce the bit rate of talks from our church for posting on the internet. The digital recorder we use records at 128 kBit/s and I reduce them to 32 kBit/s - sound quality is suprisingly good!
I want to train a backup so I’m investigating using Audacity for their use. I went through the same procedure I normally use and tested the resulting file vs that produced by Audio Cleaning Lab. It wasn’t bad, but had what sounds like a slight, but annoying, ‘swishing’ noise in the background. Could I be doing anything wrong, or is it just that not all mp3 encoders are equal! Don’t want to go above 32 kBit/s because of taking up space from our allowance an increasing download times, etc.
Ensure that your recording is mono before you export. If necessary use “Tracks menu > Stereo track to mono”. 32 kbps is too low for stereo and it will sound “swishy”. A mono show at 32 kbps won’t sound great, but will be better than stereo.
I reduce them to 32 kBit/s - sound quality is suprisingly good!
32 is the lowest possible bitrate for a relatively undamaged mono recording. 64 for stereo. Lower than that and everybody can tell there’s something wrong. You’re likely to incite a religious war about MP3 compressors. The only “real” MP3 compressor is from Fraunhofer-Gesellschaft and it’s licensed, money-based software.
If you have a high-end audio program, chances are you got the real thing and it’s pretty much as good as it gets. If you didn’t, then you got one of the work-around software packages. That’s what “lame” is. How close can we get without violating the copyrights and patents. Proponents claim the is little or no difference in quality between the free and money-based software. I don’t know, but that’s the story.
You can increase the quality of the work free by increasing the quality of the original work. Compressing a compressed performance isn’t good. You end up compressing the compression artifacts of the first recording as well as the show.