about 2,700 albums.
Holy smokes! That’s a lot, especially if you are “cleaning up” the recordings.
I’ve already done about 700 CD’s. I’ve almost exclusively used Audacity over the past 3-years and am still working on it.
I Hope you didn’t use Audacity to make digital-to-analog-to-digital recording… Normally CDs are digitally “ripped” with a CD ripping application. Audacity doesn’t do that.) Ripping is faster and if all goes well, you can get a bit-perfect digital copy and the metadata gets filled-in automatically
I keep the output from the process as VBR MP3, depending on the track, is circa 250kbps.
You might consider keeping a lossless FLAC archive, since you’re going to all that work.
- Use the Squeezebox/LMS gain control to try to achieve a balanced loudness. It’s described here. > http://wiki.slimdevices.com/index.php/A > … Adjustment
That should work reasonably well. The files do have to be pre-scanned to find the “loudness”. From quickly reading the link, I’m not sure if SqueezeCenter will write the tags, or if that has to be done by another application in advance.
The ReplayGain algorithms make a simple-single harmless volume adjustment for each song (before the song starts). They don’t use dynamic compression or automatic volume control or anything that will “damage” the sound.
There are variations such as MP3Gain and WaveGain that make “permanent” adjustments to the files so they are compatible with everything. MP3Gain has a limitation that MP3 can only be adjusted losslessly in 1.5dB steps so if you’re going to make “permanent” changes it’s better to use WaveGain on the WAV file before making an MP3.
There is also an unofficial “ReplayGain” plug-in for Audacity that can make “permanent” volume adjustments (it doesn’t write ReplayGain tags). (I think I heard a rumor that volume matching be officially added to Audacity soon.)
These algorithms are much better than simple normalization, but two different people may not agree when two songs sound “equally loud”, and you’ll run into some quiet-sounding songs with a few high-peaks that can’t be adjusted-up enough without clipping.
A couple of things are going-on with vinyl. Most of your albums are (probably) older and made before the Loudness War really kicked-into high-gear (and when they only had limited analog compression tools). They were using compression and from what I’ve read, Motown “won” the loudness war back in the vinyl days with a process they called “Loud and Clear”.
And even if the CD is made from the same master, the vinyl cutting & playback process introduces phase-shifts that end-up making some peaks higher and some peaks lower. These short-term peaks don’t affect the sound of the dynamics, but it means that a normalized (“maximized”) digitized vinyl copy will have a lower average volume the digital original, even if they both have 0dB peaks. (People who do “simplistic” dynamics measurements will say the vinyl is less compressed.) This effect is more pronounced with more-compressed masters.
- Start using compression - all sorts of reasons I don’t want to. Not least it adds another layer of processing and issues.
The “extra layer of processing” usually isn’t an issue, although you can get side-effects if you over-do it or use the wrong settings. The dynamic compression itself can be undesirable (if you enjoy dynamic music with quiet parts and loud parts).