Changing drum loops and the BPM (beats per minute) with Pro Tools has always been tricky. In fact, using a sampler was usually easier – until now. That’s because Audio Genetics has released Alkali Loop Laboratory.
Alkali is a Pro Tools plug-in that allows the tempo of a loop in REX format to be changed without pitch-shifting or time-stretching. It also has a variable-speed control that alters the pitch without changing the tempo.
You can also apply quantization to tighten up the beats and apply a “swing” amount. Alkali works well with both drum and bassline loops, allowing the correct tempo and key to be selected with the drag of a slider.
Alkali also supports Digidesign’s Direct Connect technology, so the audio can be previewed within ProTools while the application is running – perfect for trying new loops against an existing Pro Tools groove.
Once you are happy with your loop, Alkali renders this to an SDII file that can be loaded into Pro Tools.
Although REX files are normally created using Steinberg’s ReCycle package, a number of similar files can be created in Pro Tools using the SDII format. The only other software that uses REX files is Cubase Audio – but now Alkali lets Pro Tools users take advantage of the technology.
I opened a drum loop in Alkali, dropped the pitch of the loop by fiveper cent to make the snare drum sound fatter, then dropped the tempo from 117 to 115 BPM. The second bass-drum beat was not accurately in time, so I quantized to 16th notes at a strength of 65 per cent. This pulled the beats in time without making the loop sound too stiff– and that was that. The new loop for my track was at just the right tempo with a tighter bass drum, and a much fatter snare than the original.
A simple but effective user-interface, combined with an insight into the needs of anyone working with audio loops has produced one of the most useful musical tools around. At just under £200, Alkali will be an essential purchase for Pro Tools users working with loops, and will appeal strongly to users of ReCycle, Cubase and other MIDI+ audio software packages on the Mac.