Comment on Subtractor Basics (13 comments)
Go back to the tutorial
alexleonard 14 Apr 03 07:36
thanks for the write up..
i hate to be pedantic but i think mention should really be made of the true nature of the subtractor synth.
It is modeled on the theory of Subtractive Synthesis (hence the name) which is a powerful tool for the creation of a large number of variations on 32 predesigned waveforms.
The premise behind it is that, lets say using only one oscillator, you can do a number of things before even reaching the Filter section (and before touching the Low Frequency Oscillators). The default setting is that Additive or subtractive synthesis is turned off (the little o above the phase pot to the left of the wavetable). This means that the waveform generated is what is played. IE a sin wave remains a sin wave.
However, when additive (x) or subtractive (-) synthesis is turned on, the waveform generated can be changed dramatically.
If subtractive synthesis is chosen, an identical copy of the waveform is created and 'subtracted' from the original. The phase pot tells you where on the original waveform this subtraction takes place.
As a practical example: select a sin wave in oscillator one and turn the subtractive synthesis on (-), if you then move the phase pot to zero any notes being generated will disappear. This is because the two waves cancel each other out. As you increase the phase (how much out of phase these two waveforms are) the sound returns but it is altered completely from the original sound. this is because the waveform shape is being changed by this subtraction.
Very small changes in the phase offset can dramatically alter the fundamental frequencies being covered by the waveform as well as potential harmonic changes.
If additive synthesis is selected, the same as above applies, except the copy of the original waveform is added, not subtracted. If the phase offset is set at zero then the orginal waveform will just double in amplitude. Again changes to the phase offset will alter the sound produced.
These factors are crucial to the power of the Subtractor Synth and allow a vast and varied set of sounds to be generated. If the Subtractor was limited to just the 32 waveforms that are programmed on it, the array of potential sounds generated would be significantly decreased.
As it is it is a flexible and wonderful synth.
I hope this is of some assistance to people out there interested in the nitty gritty of how the Subtractor works.. i understand this was meant to be about the subtractor basics and possibly this is a little more information than would be required to start playing with the synth, but i couldnt help but elaborate on the 'glorious' possibilities of Subtractive Synthesis.
(i have turned into such a huge f**king nerd, apologies)
alex
tijn 15 Apr 03 01:48
Cheers Alex - a useful addition.
Strobe 16 Apr 03 23:05
no apologies alex - great contribution, shame upon me i've missed that point..
thx alot!
Smackbaby 21 Apr 03 23:31
" (i have turned into such a huge f**king nerd, apologies) "
Too funny.
Smackbaby 21 Apr 03 23:34
" (i have turned into such a huge f**king nerd, apologies) "
Too funny.
blackworm 29 Apr 03 09:53
alexleonard's comments are not entirely correct.
First, the term "subtractive synthesis" only refers to the process of starting with a wave containing many harmonics, and using filters to subtract harmonics, resulting in a sound with fewer or less pronounced harmonics. Examples of subtractive synthesizers include many (all?) early Moogs, the Roland Jupiter series, the TB-303, and many others. Compare this to additive synthesis, where sine waves of many different frequencies are added together to produce the desired harmonics. One example of this was the Kawai K1, where the base waves were actually generated from a series of sine harmonics in varying amounts. The original K1 had no filters.
Second, Alex was only partially correct when describing what the phase knob and "O - X" settngs do. The "-" does indeed stand for subtraction, and Alex's description of what happens is correct. The "X" however stands for multiplication, not addition. Instead of subtracting the offset wave from the original, the output of the two waves is multiplied, similar to what a ring modulator would do. This can create rich overtones or very distorted waves.
The Reason manual has a very nice description of phase modulation in the Subtractor section, along with appropriate diagrams showing multiplication and subtraction with offset waves.
alexleonard 01 May 03 01:00
im an idiot.
multiplication, of course. (maybe its just that 'additive synthesis' sounds way cooler than 'multiplicative synthesis'
although, hang on there. ive never written multiplicative before. this in fact sounds cool)
anyway, about your first point. do the waveforms other than the basic waves not contain some level of harmonics. (i suppose i should go and listen to them). apart from that i didnt know that subtractive was all about the process of subtracting from a wave with harmonics, not just a fundamental freq.
i'm learning all the time, especially if i do the second year of this course i should be really getting into the nitty gritty of it.
apologies if i caused any confusion.
i'm back by the way (phone line was out of action for a while, sorted now)
alex
blackworm 01 May 03 14:32
About harmonics. Any periodic wave (i.e. a wave that repeats itself) can be represented by a combination of sine and cosine waves (a cosine wave is the same shape as a sine wave, but it is offset 90 degrees or 1/4 the period of the wave). A sawtooth wave, for example, is a sine wave at the fundamental frequency f, with amplitude a, added with another sine wave with frequency f/2 and amplitude a/2, added with another with f/3 and a/3, and so on to infinity. (Click on this link for a nice description and drawing.)
So any periodic wave that isn't a sine wave has harmonics. The amplitude of each of the sine and cosine waves at all integer multiples of the base frequency determine the shape of the wave and the character of the sound.
mmmartin 08 May 03 13:46
is there a way to use my own recorded sounds in the subtractor? i'd love to experiment!
Strobe 08 Sep 03 16:45
nope, to use your own recorded stuff, it will be the sampler you have to use.
with the malström there's the possibility of using external audiosounds via the
according inputs on the synth's backside. maybe the new spider controls in r2.5
provide ways to combine the subtractor with an audio source, but i have not made
any experiences with these devices...
jamdee 17 Jan 04 01:03
All,
I'm brand spankin new to Reasons. What basic sounds I can use to create my own sub-basses and booms. that I can use in my R&B and GET-Crunk songs...nice thick, deep, bass line type of subs and can be heard clearly and loud with the beat?? I know Subtractor is a device for starts.
borisb 09 Feb 05 04:56
as someone that has no real knowledge of the subtractor i found this very useful... nice one!
one thing that has intrigued me since i joined rs is the use by a lot of people of matrix to control the synths in reason... is there stuff u can do with matrix that u cant with the normal sequencer? sorry if this is going off topic a bit...
sceyefeye 15 Feb 07 13:04
I have to say technical issues aside, what I really like about this article is the illustration showing the process or the sequene in which the sound travels through the subtractor. I have been messing with reason since version 1 but somehow never getting a nice crunchy bass sound. This was most definitely because I was going from 1 to 4 to 2 to 4 to 1 - you get the picture. Now I have learnt what to change/tweak in what order to control my sounds. Being an old Goa Head I am determined to generate a synth bass rather than a wave based kick drum and finally I am getting there. Now just to get some decent rhythms out of the matrix. Many thanks for the tutorial
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