SB AWE32 Developer's Information Pack
PART IV MIDI NRPN Implementation
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84
Copyright
Creative Technology Ltd., 1994-1996
Version 3.00
To convert a actual value into MSB and LSB, here are the steps:
MSB
= (actual value + 8192) / 128
LSB
= (actual value + 8192) % 128
A "Reset All Controllers" message (MIDI controller 121) will restore the instrument’s original
SoundFont parameters.
The EMU8000 Sound Architecture
The EMU8000 has an extensive modulation implementation using two sine-wave LFO’s (Low Frequency
Oscillator) and two multi-stage envelope generators.
Modulation means to dynamically change a parameter of an audio signal, whether it be the volume
(amplitude modulation, or tremolo), pitch (frequency modulation, or vibrato) or filter cutoff frequency
(filter modulation, or wah-wah). To modulate something we would require a modulation source, and a
modulation destination. In the EMU8000, the modulation sources are the LFOs and the envelope
generators, and the modulation destinations can be the pitch, the volume or and filter cutoff frequency.
The EMU8000’s LFO’s and envelope generators provides a complex modulation environment. Each
sound producing element of the EMU8000 consists of a resonant low-pass filter, two LFOs, in which one
modulates the pitch (LFO2), and the other modulates pitch, filter cutoff and volume (LFO1)
simultaneously. There are two envelope generators; envelope 1 contours both pitch and filter cutoff
simultaneously, and envelope 2 contours volume. The output stage consists of an effects engine which
mixes the dry signals with the Reverb/chorus level signals to produce the final mix. The diagram on the
next page shows the typical blocks of an EMU8000 sound element.