Alesis QS8.1, QS7.1 manual HOW the QS Generates Sound, Program Sound Layers

Part 8: Editing Programs

HOW THE QS GENERATES SOUND

The QS uses custom integrated circuits, developed by the Alesis engineering team specifically for the QS. These resemble the types of chips used in computers and other digital devices. In fact, you can think of the QS as a special-purpose computer designed to generate and process audio. Although the user interface maintains the metaphor of “modules,” in fact all sounds are simply a set of numbers reflecting how you’ve programmed the various sound parameters. For example, when you change the filter cutoff frequency, you’re not actually messing with a filter; you’re telling the computer to simulate the effect of messing with a filter.

Each “module” is represented by parameters that appear on one or more display pages. The [▲ VALUE]/[ VALUE ▼ ] buttons and the [CONTROLLER D] slider let you change these parameters. All “patching” is done via software, so the only patch cords you need are those that go to your mixer or amplifier.

You can take a “snapshot” of the QS’s parameters and save this in memory as a program. The QS comes with 512 factory preset programs, and 128 user-editable programs.

PROGRAM SOUND LAYERS

The simplest method of programming is to take one voice, process it through the filter and amp sections, and (if desired) add some effect to it. However, more elaborate Programs usually consist of 2 to 4 layers, with each layer making its own distinct contribution to the sound, for example:

•An organ program with Program Sound 1 set to a sustained organ waveform, and Program Sound 2 set to a percussion waveform with a fast decay.

•A piano program with one layer tuned normally, and a second layer tuned an octave higher.

•A synthesizer program with one layer set to a sharp attack waveform, a second layer set to an acoustic waveform, and a third layer with a slow-attack string waveform.

This may remind you of Mix Play Mode, where playing the keyboard can sound up to 16 different Programs at once. There are many similarities. In Mix Play Mode, you can make the same kind of layered Mix as you can with the four Sounds of a Program. But there are differences:

Use Program Layers:

•If you want multiple sounds to respond to a single MIDI channel. For example, if you need to play a three-way layered synthesizer sound that was assembled in Mix Play Mode instead of Program Play Mode, you must send 3 Note On messages from your sequencer (one for each channel) for every note; a layered program would need only one Note On message.

•When layers of a Program are designed to be used together, and the individual layers by themselves wouldn't be used alone (for example, the percussion layer of the organ sound).

108 QS7.1/QS8.1 Reference Manual