sxa@CXA.DARESBURY.AC.UK (White Rabbit) (02/22/90)
vis - a - vis > From: Yary Richard Phillip Hluchan <yh0a+@EDU.CMU.ANDREW> > Subject: Various forms of synthesis >Here are the methods of electric synthesis I've heard of: > >additive/subtractive I would say that additive and subtractive synthesis are two rather differnt methods, but if you understand them then you already know this... >FM >sampling >granular >LPC >I understand the principles behind each of these, except for granular & >LPC. I'd like someone to explain the processing involved, and point out >any methods I missed. Granular and LPC are two i know little about, apart from the fact that granular synthesis appears to involve 'sequencing' parts of the waveform over time... LPC seems to be of a similar principle to vocoding where bands of frequencies' amplitudes in the input signal are modulated according to the equivalent in the 'control' signal, thus giving, say a synth voice the formant movements of a human voice... if this isnt LPC, it IS analogue vocoding... Others : Karplus-Strong where the output is effectively an interpolation between two waveforms, but is also 'fed back' to replace one of them... the harmonics thus die off as they would in a plucked instrument. Waveshaping : Where a sine (or any other wave) is used as the indice to another waveform... altering the amplitude of the sine wave causes the change in timbre. Wavetables : like samples, in a way, except that the table consists of a series of waveforms, and the actual waveform read out from is what is modulated... Transitions may be interpolated or 'raw'... see the discussion about the Waldorf on this list for more info... VOSIM : Cosine waves are read from a table with three parameters altering the timbre... they are (I believe... )damping of the wave over time, frequency, and distance apart (? been a while, cannae remember, but it sounds about right). Good for vocal sounds. 3D Waveshaping : As Waveshaping, but using two indices, and a 'cube' waveform table. Ive also got one of me own... but that's staying secret until (a) I can check if it works and is predictable and (b) I can sell it to Yamaha, a la Chowning, and make my fortune... well enough to get me a box of 56000's and a couple of Gb of Hard-Disk... hehehe. I asked about books on this list not so long ago - so if youve seen the replies I got you should be able to look in them for more info... Ive got to find them in the UK first, though. ******************************************************************************* White Rabbit : found in these burrows * * JANET : sxa@uk.ac.dl.cxa * Internet : sxa%cxa.dl.ac.uk * ...and the dormouse said EARN/Bitnet: sxa%cxa.dl.ac.uk@UKACRL * UUCP : sxa%cxa.dl.ac.uk@ukc.uucp * feed your head. Ean : sxa%cxa.dl.ac.uk@ean-relay.ac.uk * *******************************************************************************