As a former DJ, I have been asked to offer some advise to a newbie who wants to run music from a laptop. He will be encoding about 1500 songs and can't decide between formats. AAC, MP3, Vorbis...ect

I put my gear out to rest before going the all digital route (so I can't perform any tests).

I was wondering if anybody has sampled the quality difference between lossy codecs - in running through mobile DJ equipment (extreme volume).

When I last played a few mp3's at this kind of volume - the result was quite unappealling. One could hear a huge difference between the CD's vs. Mp3.

At the moment I am suggesting my friend encode using MPC (q7) as it seems to provide tons of punch and good clarity though home speakers. But I really can't be sure what will deliver the best result in a small hall.

Would love to hear what anybody else has been using for this kind of application.

Regards

Vorbis with the latest version of atoUv (I never remember how to spell this) should cut it easily - as long as it's only for playing on his computer (lack of hardware support, generally, plagues this format); Otherwise, mp3 with the latest version and recommended settings shouldnt yield a noticeable difference, especially with speakers (try lame v3.97b2, -V 2 --vbr-new)
Wavepack lossy is also a good bet.

Try in that order.

MPC has slower seeking, and support seems to be on the downturn...

what Shade said about OGG or LAME MP3 --vbr-new

I am all for joint stereo, but there has been some reports of JS not playing nicely when used in a mono playback chain.

where?

It's been reported on the forums, but it's way too late for me to look for them now. Maybe tomorrow.

He could connect an external USB hard drive and encode straight to lossless (wavpack, flac, MAC) - this will consume approx 40GB and encoding will be a lot faster than lossy.

This, of course, is the best solution.

In firewire, it'll actually be faster than the internal hard drive, if you take a 7200 turns / min.
You can even boot windows off it (or whatever OS he has)