Recording levels question


My trusty old tapedeck is giving up on me and while it hasn’t completely given up on me I’m transferring my recordings to a Mac. I followed the directions in this post and followed the wiki manual. I have Audacity 2.0.1 installed.

My question relates to this page specifically.

So far, I’ve transferred several tapes and while doing so I noticed that the original volume level (some tapes are very old and I may have incidentally adjusted the original recording level) changes over tapes. So that means that I should adjust the monitors accordingly with every tape? How does that affect my recordings when I’m playing them back? Also I think that the volume is somewhat soft (to get it down below the -6.0 dB). If I turn up the volume, I’m sure there’ll be some clipping. What’s your experience with this? Is there some way of increasing the volume perhaps afterwards? I don’t want to blow out my ears switching from a tape-recording to cd/mp3/radio or whatever.


There is a full set of tutorials covering every aspect of this job:

-6 dB is often quoted as a good guide to a suitable recording level. The really important thing is that the recorded waveform should not hit the top or bottom of the track. The top/bottom of the track represents 0 dB, and attempting to record higher than that will automatically produce clipping (distortion). It does not matter if the peak level goes a bit over -6 dB as long as it remains below 0 dB at all times. If the peak level is a long way below -6 dB then you will not be getting optimum performance out of your sound card. The peak recording level is not ultra critical, -6dB peak level is a guide. The important thing is to stay below 0 dB.

After recording you can use the Normalize effect (Effect menu) to bring the peak level up a little higher. Normalizing to about -1 dB is generally considered to be a good guide before Exporting.

As for the tapes that change over time, you may be able to make good use of a dynamic processor like Chris’s Compressor.
It will try to follow the overall loudness of the show and adjust as you go similar to a radio station. Ever notice you don’t have to constantly adjust the volume of the radio in the car? That’s why. You will notice that if you have a long period of silence in the show, Chris will sometimes try to make the background noise into show, so that doesn’t work very well.

But for most entertainment shows, it works very well. I use it to process podcasts before I put them on my iPod. Podcasts are completely unprocessed and you’re at the mercy of whoever was running the sound mixer.

If you like listening to “Fresh Air,” for example, The broadcast version is a perfectly enjoyable hour. If you go running/jogging/walking with the podcast, you’ll find immediately that Terry’s voice is a lot louder than the guest and you’re constantly adjusting your iPod to hear everything.