Signals can be used to control Max data flow, either signal data as well as standard max data.
Actions and events can be in fact operated through signals. With different qualities and numerical flows of a signal, we can achieve different types of control.
A signal can be polar or unipolar for example, it can have a curved shape (like cycle~) or a linear ramp (like phasor~). It is important to know precisely the types of motion signals operate, and their numerical range, starting from the usual bipolar range of -1 to 1 and the unipolar range of 0 to 1.
Take for example phasor~: it gives values that ramp from 0 to 1 at a certain speed. In fact, it is often used to drive playback objects like play~ or wave, as its ramp can be easily expanded to the length of a sample file.
if you multiply the phasor 0-1 ramp by 3000 you will obtain a 0-3000 ramp, which can be used to read from a sample buffer for example.
Being able to do mathematical operations with signals allows us to also create several interferences and modifications useful for control and/or musical purposes.
For example, a simple linear ramp made with line~, if that is made passing through a pow~ object it will take an exponential curve shape, which would give the ‘trajectory’ and behaviour of the signal a different feel.
The object downsamp~ can instead disrupt the resolution of a signal passing though it, creating steps in the signal. The most obvious example is what it does to a simple sinusoidal oscillator. Downsamp~ does not let all the samples generated by cycle~ pass through, but just check every 5000 of it. The resulting output is a signal formed not by 44.1 samples per millisecond but every 100 ms or so, which creates less resolution.
Disrupting creates steps, non-linear flow of data, which artistically can be used in several ways. In synthesis, when scaled appropriately, that can create steps in frequency, and it can be used to drive an arpeggio effect for example,
Also scaling can be applied (scale~ object) to a signal, very much in the same way as the scale object for Max data signal.
The object number~ comes very handily to check what’s going on within a signal, have a glimpse into what numerical data is triggered.
Application
Using signals in this fashion can be directly applied to synthesis, as mentioned earlier. Interesting effects can be realised if applied to carrier and modulators.
By simply adjusting the rate of phasor~ to read through a sample length at the sample rate speed (any faster or slower would cause perceivable pitch changes in the sound), it can be also used to drive a play~ object pointing to a sample buffer.
Shortening, or scaling, or degrading the signals would correspond in a non-linear playback of a sample file, ‘buffer-shuffler’ or on the likes of plunderphonic style.
Please check out the stutter effect here:
It shows a very clever way to controlling/creating playback effects with signals.