When this has been done, all deleted voices will be set to the standard default sine wave. The pre-set wave numbers zero and 1 can be manipulated, but they cannot be eradicated.
Making audio envelopes
An "envelope" is audio jargon for how a sound is manipulated during the brief period of tin
that it is played. In other words, whether it bursts into life or makes a more subtle entry (attack),
whether it fades away with dignity or lives life to the full (decay), how long it hangs on for
(sustain) and finally, the manner in which it meets its end (release). All of this is achieved simply
by changing the volume of individual sections of the wave form.
SET ENVEL
instruction: create a volume envelope
Set Envel wave number,phase number To duration,volume
AMOS Professional uses envelopes to change your original wave forms according to a set pattern. The parameters are as follows:
The wave number sets the wave form to be affected, and any number can be used including the pre-set wave numbers zero and 1.
The phase number refers to one of seven individual sections of the original wave form that is to be defined, ranging from 0 to 6.
The duration controls the length of this particular segment (phase number) of the wave form, and is expressed in units of one 50th of a second. This is how the speed of a volume change in any phase of the wave form is controlled.
Volume specifies the volume to be reached by the end of this phase, ranging from zero for silence up to 63 for full blast.
In the next example, an envelope for wave form number one is set, so that segment zero (its first phase) lasts for four seconds, ramping up to full volume by its end, no matter what the original volume was at the start of this phase.
X> Set Envel 1,0 To 200,63
LED ON
LED OFF
instructions: toggle audio filter
Led On
Led Off
Most tape recorders and hi-fl systems have some sort of filtering system to "clean" up sound by eliminating the high frequencies that generate unwanted hiss. When filters are used, there is always a trade off between overall sound quality and clear definition.