Definitions: How The Emulator Ii Organizes Sound; Sampling Basics - E-Mu EII+ Owner's Manual

INTRODUCTION

DEFINITIONS: HOW THE EMULATOR II ORGANIZES SOUND

Forget everything you've ever learned about voices, presets, and channels: The Emulator II
does things differently from traditional keyboard instruments.

Sampling Basics

The Emulator II is conceptually like a tape recorder in that it records sound. However, the
recording process is very different since the Emulator II is recording into computer memory.
Computers can accept information only in the form of numbers, so the Emulator converts audio
signals into numbers. It does this by examining (sampling) the incoming signal level 27,500
times a second, and sequentially recording these different levels in computer memory.
Figure 1 shows a one-second percussive sound being sampled. The magnified view shows
how the samples define the instantaneous level of the signal. Once stored in the Emulator II's
memory bank, these samples may be played back (in the proper sequence, of course) to
reconstruct the original signal. If a two second sound was being sampled, it would require
2x 27,500 or 55,000 samples. Shorter sounds require fewer samples.
Figure 1
Just like tape, a sound can be manipulated once it has been recorded. Playing back, the
samples in the reverse order from which they were stored plays the sound backwards. Playing
back the samples at a faster rate than the rate at which they were stored raises pitch; playing
back at a slower rate lowers pitch (like a tape recorder's variable speed control).
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