[ipaqlinux48]

I assume that you've read the manual. If not, please read it! At least you should know something about subtractive synthesis (osc->filter->amplifier->effects + lfo routing) before you can start programming your own sounds.

Anyway, a hooversound is mostly the effect of two or more (the more the fatter it'll sound) sawtooth osscilators slightly detuned. A square wave will do the job too. Assign an lfo for PWM (pulse width modulation) to alter the harmonics. To give your hoover sound a boost, use the sub-osscilator. Oh yes, don't forget the filter: a classic 12 dB LP filter is fine. You can use an expression pedal to control the cutoff frequency, ?t voila!

But I'm sure that Juho can explains it better because he loves hoovers .