An easy way in Audacity to make it sound bad would be to:
1. Choose 'Noise Reduction'
2. Get the noise profile of the entire clip
3. When choosing settings, make sure
- 'Noise Reduction' is at max (48db)
- Sensitivity is at a custom 0.10 (you'll have to put that in yourself since the slider only goes to 0.50)
- Frequency bands is at 12
- Set to 'Reduce' and not "Residue'
After that, the mic should sound realistically stuff, but we're not there yet.
4. Go into 'Equalizer' and down to the 'Curves' dropdown. Select 'Bass Cut' and then 'OK'
5. Lastly, use Amplify to get the volume back up if it turns out to be too quiet.
Doesn't remove quality (via things like setting the project rate all the way down) and sounds realistically stuff.
If you're going for obnoxious stuff quality, you could just use some distortion filter.
