BBE DI-400 - Manual (Page 4)

Loudspeakers have difficulty working with the electronic
signals supplied by an amplifier. These difficulties cause
such major phase and amplitude distortion that the
sound reproduced by speaker differs significantly from
the sound produced by the original source.
In the past, these problems proved unsolvable and were
thus delegated to a position of secondary importance in
audio system design. However, phase and amplitude
integrity is essential to accurate sound reproduction.
Research shows that the information which the listener
translates into the recognizable characteristics of a live
performance are intimately tied into complex time and
amplitude relationships between the fundamental and
harmonic components of a given musical note or sound.
These relationships define a sound's “sound”.
When these complex relationships pass through a
speaker, the proper order is lost. The higher frequencies
are delayed. A lower frequency may reach the listener's
ear first or perhaps simultaneously with that of a higher
frequency. In some cases, the fundamental components
may be so time-shifted that they reach the listener's ear
ahead of some or all of the harmonic components.
This change in the phase and amplitude relationship on
the harmonic and fundamental frequencies is technically
called “envelope distortion.” The listener perceives this
loss of sound integrity in the reproduced sound as
"muddy" and “smeared.” In the extreme, it can become
difficult to tell the difference between musical
instruments, for example, an oboe and a clarinet.
BBE Sound, Inc. conducted extensive studies of
numerous speaker systems over a ten year period. With
this knowledge, it became possible to identify the
characteristics of an ideal speaker and to distill the
corrections necessary to return the fundamental and
harmonic frequency structures to their correct order.
While there are differences among various speaker
designs in the magnitude of their correction, the overall
pattern of correction needed is remarkably consistent.
THE BBE PROCESS—"WHAT IT IS"
4