I’m very new to audio editing, so I don’t know a whole lot… but I’m learning!
I’ve got some concert choir recordings from college that I love to listen to, but there’s a problem… several of the years’ recordings have bad distortion when the music gets very “intense” and loud. I read some on the forums and it sounds like there’s unfortunately no way to clean up distortion if it comes from too much gain or input…
However, in my case I get more or less distortion depending on which speakers I use to play the music. My phone and bluetooth speaker have lots of distortion, while my computer speakers do better. I suspect if I had a really fancy stereo system it would handle it even better without distortion. This makes me wonder if there might be a way I can adjust the recordings so that they will play better on small speakers?
I’m hoping (fingers crossed) that the original recording wasn’t clipped, it’s just too much for my current speakers to handle. If that’s the case, what can I try to fix it?
Normally I’d think it’s the bass. You can easily distort amplifiers/speakers with bass that your speakers can’t reproduce or with subsonic frequencies that you can’t even hear. But if this is a “pure vocal choir” there shouldn’t be much bass. If there’s an amplified band and/or drums (or a pipe organ) that could be the problem. But go-ahead and try reducing the bass with the Graphic Equalizer or the Bass & Treble effect.
Typically with a phone or computer (and maybe the Bluetooth speaker) you can’t clip the built-in amplifier without clipping the DAC. So, if the file isn’t clipped it’s most likely the (mechanical) speaker that’s distorting, Although, some player software can amplify the digital audio, and the equalizer built into your player software can also clip the DAC (depending on the digital volume control setting).
Another thing you can try is using the Envelope Tool to slightly fade-down the loud-distorted parts. You are correct that this won’t remove the distortion in the file but it could make it slightly-less annoying. The “trick” with the Envelope Tool is to fade-up and fade-down without changing the end-points so there are no sudden unnatural jumps in volume.
I suspect if I had a really fancy stereo system it would handle it even better without distortion.
Maybe… Sometimes it makes the distortion more obvious or makes the differences between good & poor audio more noticeable.
If you have a pair of headphones, try them.
I’m hoping (fingers crossed) that the original recording wasn’t clipped,
Audacity can [u]show clipping[/u] but it’s only a “clue” or a “hint”. For example, if you simply reduce the level you’ll “hide” the clipping from Audacity (false negative) and if you Amplify you can “see red” where the digital data isn’t really clipped (false positive).
If you are recording with Audacity and you “see red” before any editing/processing then you really did clip your analog-to-digital converter during recording.
The best way (besides listening) is to zoom-in and look at the waveform peaks to see if they are flattened. Oh… You also need to enter a negative number into the Amplify effect so you can actually see the peaks. If you have “pure digital clipping” it’s pretty easy to see. But, you can have analog clipping/saturation that’s not always as obvious and lossy compression (MP3) or certain effects can distort the wave shape too so you don’t always get perfectly squared-off peaks and it’s not always easy to see.
Also, you might try running Compressor effect with the Threshold changed to -60dB and Ratio set to 4:1. This will bring up the quiet parts so you don’t have to have the volume up so much that it causes distortion during the loud parts.
I hope this helps.