re-edits.... best way of lowering tempo


Pound Shop Alex Petridis
i want to take a load of proggy tunes that are (i guess) about 130-138bpm and slow them down to about 120-125...

obviously one way to do this is on the fly with the CDJ pitch control; but the sound quality suffers a bit, i find..... would soundforge or something produce better results or is it essentially going to be the same whatever the method?




It depends you've got two options:

Pitch shifting will slow it down without much quality loss but obviously you will change the sound of the whole thing quite a bit. (plus you'll lose all the high frequencies and may force the low frequencies down to low)

Alternatively use a time stretch algorithm which will maintain the pitch. This will potentialy cause more quality loss depending on the algorithm you choose - some are more sophisticated than others and some are more suited to certain types of sound.

Some algorithms are designed for drums - they aim to maintain the transients and just pad out the spaces between sounds. Others are designed for sustained notes - they effectively patch in extra cycles to lengthen notes. If you have Cubase SX - the advanced time stretch algorithm is really good - it uses some sort of adaptive hybrid of the two methods so is better suited to general music.. its miles better than the soundforge ones that I've tried.

There are probably some other good stand alone software algorithms around - I've never looked.. decent advanced ones are probably expensive!

Dropping from 130 to 120bpm is a fairly hefty decrease so I think noticable quality loss is inevitable. Sounds such as reverb suffer particulalry badly...