Sound quality for a laptop DJ

I am a DJ making tentative steps into digital music. I have a MacBook, which I will incorporate into my sets. How can I ensure music CDs are imported at the highest possible quality? Also, what is the difference between a music file of 320kbps and a WAV file?
Stuart Eve

For maximum sound quality you will need to do some secure ripping, where the standard is a Windows-only program, EAC (Exact Audio Copy). The guide at Hydrogen Audio reckons XLD (X Lossless Decoder) is a Mac equivalent, and it’s the only application for Mac OS/X that uses the AccurateRip database used by both EAC and dbPowerAMP. Max looks like a good alternative.

WAV, the waveform audio format, is a Microsoft file format that usually contains uncompressed audio using linear pulse code modulation or LPCM. Audio CDs also use LPCM encoding, so a WAV file can provide the same sound quality as the CD. (The Mac equivalent is AIFF.)

WAV files are easy to edit but very large, as shown by the number of tracks on an audio CD. Their size can be reduced by using a lossless compression system such as FLAC (Free Lossless Audio Codec). However, most people convert to a lossy format such as MP3, AAC or WMA. This produces very small files, but there is inevitably some loss of quality. Whether the difference is audible is another matter.

Briefly, very few untutored people can hear the difference between a 256kbps LAME-encoded MP3 file and a WAV file. (You can learn to hear differences, but why would you want to?) However, this depends on the quality of the reproduction. The fact that you can’t hear the difference on an MP3 player with nasty earbuds or a tabletop DAB radio doesn’t mean they won’t be audible through a decent hi-fi with studio monitors. You therefore need to do some listening tests with your own equipment to find out if you can hear the difference. As laptop computers are not hi-fi devices, I’d be quite surprised if you could consistently tell 320kbps MP3 or (technically better) AAC files from WAV files when both are played from a MacBook.

Incidentally, MacRumors has a very brief guide to DJing on a Mac, with links to the most popular software and devices. As you’re combining digital with analogue sources, you may find a digital vinyl system such as Serato Scratch Live of interest, albeit at a hefty price.