Posted by: Anonymous
on October 21, 2008 03:15 AM
Audacity has an option to "Show Clipping". It will draw a vertical red line through any sample that hits a positive or negative maximum. If you're getting a lot of those, back off the input level a tad and restart your recording. An excess of clipping sounds plain awful. I won't tolerate more than a few single sample clips on an entire LP side. Note: If you use the Normalize effect, you will get at least one red clip line. Normalize finds the difference between the loudest sample in the recording and the maximum signal level and adds that to each sample. I always do that as as a final step after any pop/click removal or other cleanups but it isn't a substitute for having good signal in the first place. Especially when you are recording with 16 bit consumer gear and need every bit of dynamic range you can get.
I also take issue with the advice to record in 24 bit. Unless you've splurged on a spendy prosumer or pro audio card, you aren't going to actually capture at 24 bits. At best, Audacity will just upsample the recording. That isn't a bad thing necessarily if you intend to run a lot of filters on the audio but it won't turn a cheapo 16 bit audio card into a 24 bit one and if you want to avoid aliasing due to running filters then I'd just upsample manually after capturing at whatever the card can actually do. Of course, if you actually have a 24 bit card then do it. With dynamic range like that, you can afford to not have to back off the input volume due to clipping. Just set a level that is consistently more than 16 bit then normalize and downsample to 16 bits when all other processing or cleanup is done.