Is there any way to keep the recording level above a minimum automatically when recording from sound card. Example is the original music was recorded very low volume in many sections. Can I set an automatic increase in volume level if the source goes below a certain level?
No, Audacity records the signal as it is, but you can use Compressor to reduce the dynamic range of the audio once it has been recorded. By default it will increase the peak level to the maximum of 0 dB after having reduced the dynamic range.
Gale
I think what you’re asking about is “upward compression” in which low parts are raised instead of peaks being smashed down and then ALL of it raised. You can achieve this effect in a blunt manner by selecting the “compress based on peaks” option in Audacity’s built-in Compressor filter.
Yes, though Audacity’s upwards compression also increases the louder sounds above the threshold to some degree (unless that audio is already at 0 dB), as well as increasing the sounds below the threshold to a greater extent.
Gale
Thanks for the clarification. I ended up trying Chris’s 1.2.6 compressor and - for the piece I was working with, which was orchestral with full (and I mean FULL) dynamic range in a mix with a bunch of squashed pop songs - got results that were much more to my liking when I needed upward compression. The lowest ratio in the built-in Audacity compressor was way too aggressive at raising the quiet parts.