NGWave Audio/Sound/MP3 Editor: CD Burning Part I

It seems like everyone burns CDs these days. The technology and media are relatively inexpensive, so just about anyone can rip a few songs from various sources and compile them into a CD.

But what about quality? Sure, many people probably don't care about quality, and likely wouldn't notice the difference between a beautifully-mastered recording and a 128k MP3...

However, there are still many of us who like to have the best quality, and for a CD, consistancy. So how do you take that handful of files you have, and make them fit nicely together? Some tracks may be relatively quiet, while others may be loud. Some might be very dynamic, others crunched to the max. How do we correct this so the compilation flows nicely?

Guidelines

First Rule of Thumb: the less processing, the better. You may be tempted to equalize your songs to try and make them sound better. Don't EQ the source! Any equalization should be done at playback time, specific to the needs of the playback system.

So unless a file is badly recorded or mixed, it shouldn't be EQ'd prior to burning.

You may also be tempted to use dynamic compression. When used correctly, compression can be very helpful in making your files sound consistant -- but when used improperly, it can lead to very annoying side-effects.

For the purposes of preparing a file for CD-burning, compression should only be used as a corrective measure. In most cases, the songs you are planning to burn have already been mixed and mastered -- they don't need further processing.

Howto: Volume Level Consistancy

With the above in mind, how do you make the volume levels consistant?

First, simply Normalizing all of the files usually won't cut it. This is because songs that are heavily compressed -- like most modern Pop and Rock -- will be much louder than older songs, even with the same peak levels. Anything that was Digitally Remastered is generally very dynamic -- and very quiet.

Second Rule of Thumb: Aim Low. Don't go for loudness -- that's why your CD player has a volume control. You're better off with a quiet CD than a clipped and distorted CD. Studios often max out the 16-bits of available resolution in order to appear louder than the competition. Unfortunately it leads to heavily compressed -- and sometimes heavily clipped -- recordings.

So take your loud songs -- heavily compressed songs -- and click the Normalize button. Likely the level control will be at 0 db, which indicates that the song is already maxed out. Whatever it recommends, lower it by 3 db. If it shows a +1, then drop it to -2.

Now, your quieter, more dynamic files should be Normalized to 0 db. Obviously these numbers will depend on the music, so use your ears and make a judgement as to where each song belongs. The primary thing to note is that you don't want to end up with a lot of clipping.