I love banging away on my thighs and knees, and I feel that I make some of my most interesting drum patterns in this way. However, I have never felt I could get the same level from using MIDI drum pads, or bashing away at my MIDI keyboard. How could I build a controller with a pair of panels that are velocity-sensitive to sit atop my thighs? Preferably these would be as thin as possible to maintain the feeling of my playing style. Any ideas?
News Editor David Greeves replies: First of all, you're not alone! Lots of people find bashing out a rhythm on the edge of the desk or on their knees much more intuitive than using a MIDI keyboard or the tiny finger pads on many drum machines. There are plenty of alternatives out there, though which is the right one for you will depend on your personal thigh-slapping style.
Some favour dedicated drum pad controllers which offer larger pads than most all-in-one drum machines. Akai's MPD16 provides 16 MPC-sized pads, while Roland's SPD6 offers six large pads. Both will sit happily on your lap. Roland's HPD15 Handsonic percussion controller, which we reviewed in SOS October 2000 could be an even better option. It has a very large circular pad, divided into various different zones. If you just want something to bash away at, you could ignore these (along with the HPD15's other bells and whistles, like its ribbon controllers and D Beam), hit the pad wherever you like and then change the MIDI notes in your sequencer once they have been recorded. Their timing and velocity will be preserved, and that's the important thing.
If you can't find a commercially manufactured device that meets your needs, you may have to take matters into your own hands. You could have a go at building your own controller using piezo transducers. Paul White's excellent how-to article on the subject is available on our web site — surf to www.soundonsound.com/sos/1995_articles/aug95/diydrumpads.html — and is recommended reading. The suggested method is to attach a piezo pickup to the underside of an old coaster or table mat, the top of which is then covered with rubber to provide a comfortable playing surface. A second coaster or mat is attached to the underside, seperated by spacers and the piezo pickup connected to a standard two-wire jack socket. However, you'll need a MIDI drum machine which accepts a drum trigger pad input in order to turn the signal from the piezo pads into MIDI. Not many machines have trigger pad inputs these days — the Alesis DM5 and DM Pro modules are a notable exception, and are listed in their current catalogue. You could also hunt down a second-hand Alesis D4 or Akai ME35T.
You will need to consider the issue of velocity sensitivity too. The pads which Paul White explains how to make are really intended to be played with sticks. You'll need to experiment with different materials to produce a pad sensitive enough to be played with your hands, whilst isolating the piezo tranducer sufficiently so it isn't triggered accidentally. In any case, home-made pads will be less velocity-sensitive than manufactured units, and even they can struggle to translate the subtleties of acoustic percussion (which includes knees!) into MIDI data. This is something you'll have to live with.
One final suggestion is that you get hold of a USB-capable dance mat (of the sort which accompanies arcade-style dancing games) and assign its sensors to trigger MIDI notes. This is easily done in Ableton Live and you could happily drape the matt across your knees. The sensors on this kind of device aren't velocity sensitive but timing could at least be recorded. You could even go one better, cut up the mat and incorporate the sensors in the world's first pair of MIDI lederhosen! Where you put the USB port is up to you...