Paul White proffers a few useful suggestions and tips to enable handclap sounds to be recreated using commonly available items of musical equipment...

To synthesise any natural sound successfully, it is first necessary to understand the mechanism whereby that sound is produced, and in the case of the handclap, there are at east three parameters which must be examined before deciding which pieces of equipment are required to produce a reasonable electronic simulation.

Parameters

When you clap your hands, a single percussive event occurs which may broadly be analysed as follows:

The initial 'slap' is produced by the rapid displacement of air when the hands are brought together and this is filtered acoustically by the resonant cavity formed by the cupped hands. Depending on the shape of the hands in question, the sound filtering will vary and, in general, the more cupped the hands, the more resonant the sound. External acoustics also come into play and the reverberant effects of the environment contribute significantly to the final perceived results.

Having several people clapping together complicates the analysis further, as there will always be a slight difference in timing between individuals and the resonant frequency of each persons' cupped hands will to some extent be different. In terms of synthesis then, we have isolated at least three parameters that need to be simulated electronically.

Simulation

First, we need to produce the effect of the initial shockwave, and this is most readily done using a burst of white noise, having a sharp attack and a fairly rapid decay. A suitable source could be a percussion synthesiser such as E&MM's 'Synwave', or a noise burst set up on a conventional synthesiser. Good results can also be obtained by using the snare drum voice of a drum machine as the raw noise source, and the author has achieved very acceptable results with a Roland TR606 Drumatix.

The second phase consists of producing a short delay or echo to simulate the timing difference between individuals, and a digital delay line such as the Powertran unit should give excellent results, though an analogue until will also suffice. A delay time of between 20 and 60 milliseconds is generally most effective, and if your unit has no time readout, set the delay to minimum and then gradually increase it until the sound just starts to resolve into two separate beats.

Experiment with delays in this area until you find the value that gives a good 'feel', and then add just a hint of feedback to spread the sound slightly. The delayed sound should be roughly the same level as the direct sound and it sometimes helps to overdrive the delay unit, as the extra harmonics produced by the distortion can add to the realism of the effect.

The final treatment, with the exception of reverb which can of course be applied at your discretion, is to pass the echoed noise burst through a band pass filter to simulate the 'cupped hands' resonance, and a small graphic equaliser is ideal for this purpose. Heavily boosting bands around 1 KHz and cutting all the others, particularly the low frequencies, is a good starting point and the effect can be refined by further experimentation. If you don't have a graphic equaliser, you can use a parametric or sweep EQ (or even a wah-wah pedal) and don't forget the EQ on the mixer if you have one.

An alternative approach is to use the audio input of a synthesiser and manipulate the filter frequency and resonance controls to achieve the desired effect.

As an absolute last resort, you could try clapping your hands near a microphone, but be warned, the results are seldom as good as the real (electronic) thing.