Apple Logic Express 7 - Manual (Page 294)

294 Chapter 11 Sample Editor
Also remember that the quality of the result depends greatly on the source material.
Don’t let this keep you from experimenting. Feel free to try extreme settings for
compression/expansion or transposition. In such cases, the result may not always be
what you expect, but it might be just the “effect” you’re looking for.
You can move the ball in the 3-dimensional display with the mouse. Naturally, only two
dimensions can be accessed at once; use Shift to switch between two different 2-
dimensional planes (enabling you to reach every point of the 3D graph). Holding
Control, Option, or Command limits ball movement to one axis, allowing independent
timbre, transposition, or length changes.
You can also grab and move the shadows of the ball. These are its projections on the
timbre axis, and the transposition/time plane, respectively
The position of the ball directly effects the numerical values, and vice versa.
You can reset the ball and all numerical values to centered (neutral) positions by simply
double-clicking in the graphic display.
Time Machine—Technical Background
The Technology of the Time Machine
The Time Machine analyzes the spectral components and dynamics of the digital audio
material, and processes the result. The high-grade algorithm endeavors to retain as
much spectral and dynamic information as possible, and minimizes phase variations. In
stereo files, the phase relationship between the left and right channels is fixed, and not
altered. Doubled sound events are kept to a minimum. This approach produces a high
quality result, which is smoother than what you’re probably used to hearing from other
products, despite the speed of the process.
You should, however, bear in mind that apart from resampling (transposition), the Time
Machine has to achieve the “physically impossible”: when a sample is lengthened,
information needs to be “invented.” This should be as realistic as possible. Conversely,
when a sample is shortened, information has to be cut out. This cut information should
be as unimportant to the overall character of the sound as possible. Lengthening is
more difficult than shortening, and if you have a choice, it’s better to speed up a drum
loop than it is to slow it down.
There’s always a small deviation between the set stretch or compression factor, and the
actual result. This is because the algorithm needs some freedom to optimize the
spectral and dynamic integrity (the sound quality). The deviation from the set value is
only a few milliseconds (or fractions of a bpm). This shouldn’t present a problem, as the
absolute deviation is independent of the length of the processed section. Put another
way, this means the deviation is no greater in longer files.