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Freebirth

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The Main Window

The main window consists of the sequencer, mixer , and bass synth controls for Freebirth. The sequencer is devided into 16 steps. The buttons in the bottom row trigger the bass section. The sliders above each bass step are the pitch controls for the bass for each step. Above that are 5 rows of smaller buttons. These are the triggers for the sampled component of Freebirth. At this moment from top to bottom they are:

Sample
Open Hat
Closed Hat
Snare
Kick

The pitch controls for the samples are located in another window(see Sample Pitch Window below).

Bass Synth

The bass synth consists of three oscillators. A sawtooth wave oscillator, a square wave oscillator and a sine wave oscillator. These are blended together to produce a variety of timbres. The amount of each type of wave which makes up the bass synth signal is controlled by the blend knobs. These are not a normal mixer. Rather they mix the different types of waves in relative to each other. The output is always constant but the makeup of that output is some relative composition of all three waves. Next to the blend knobs are the phase knobs. These control the phase of the each of the oscillators relative to each other. This is a subtle effect and is only really audible when the oscillators are tuned to the same note. Its result is a more full, less present modulating type sound. Finally next to the phase knobs are the frequency knobs. These control the tuning of the oscillators relative to each other.

The filter section consists of controls to shape the output of the oscillators as well as a filter envelope to control how the filter cutoff changes over time. It is a basic resonant low pass filter. The Q dial controls resonanse whilst the cutoff dial controls the cutoff frequency of the filter. The attack and release dials control how the filter changes over time. The attack is the time it takes for the cutoff frequency to reach the cutoff you have set with the cutoff dial. The release controls how long it takes for the filter cutoff to return to zero.

The amplitude envelope section for the bass can be found on the lower left and consists of the knobs amp attack and amp release. These are used to shape the volume of the bass synth over time. The amp attack controls how long it takes for the bass synth to reach maximum volume at which point it starts its decay, whose length is in turn controlled by amp release.

The Mixer

The mixer consists of a slider controlling the volume of each of the sound producing parts of the program as well as two auxillary sends which go the the effects. At this point the effects sends are pre fader, which means that even if you have the volume knob all the way down, there will still be a signal returning from the effects bus if you are sending some via either of the effects send controls above the sliders. The first send currently goes to the multi tap delay module whilst the second send goes to the reverb module.

The Effects Window

The effects window contains the controls for the integrated effects of Freebirth. Right now these are delay and reverb.

The delay module is located on top and consists of 3 delays making up a sort of multi tap delay. Delay times are entered in milliseconds into the text boxes. The dial next to the delay time controls the feedback of each tap. Finally the third knob controls how much of that particular tap will be sent to the output of the delay module.

The reverb module is a primative reverb based on the classic Shroder design of multiple parallel comb filters(delays) being mixed down and fed into two all pass filters for softening. This is exactly what the controls on the reverb module refer to. The six rows of two knobs on the top control the delay and feedback of each individual comb filter respectively, while the two sets below them represent the phase correction and feedback parameters of the all pass filters, grouped horizontally.

The Sample Pitch Window

The sample pitch window is used to control the pitch of each of the samples for each step. They are layed out coressponding to the step sequencer in the main window. Their range currently allows an octave of tuning in either direction. Each row corresponds to the 16 steps for one instrument.