Whether bringing out the subtleties in all aspects of recording,
mastering, postproduction, and live performance, or lending
character to audio broadcasts, the Dolby®740 Spectral Processor
provides a high level of flexibility in audio processing. Based on
the versatile filtering characteristics of Dolby SR noise reduction,
this two-channel dynamic processor allows boosting of low-level
signals while leaving high-level signals untouched. Like a
magnifying glass for sonic details, the Spectral Processor allows
you to tailor your sound like never before.
The Dolby 740 processes low-level signals in a side chain, where
as much as 20 dB of boost can be added in low-, mid-, and high-
frequency bands. The side chain’s signal is then added to the
original input signal, resulting in an output with the low-level
details boosted, while the high-level signals remain unaffected.
For maximum effectiveness, the threshold below which the
processing occurs, the amount of boost in each band, and
the crossovers between bands are all user-adjustable. A gentle
sliding-band noise reduction circuit providing up to 12 dB of
action is also included, to reduce any source noise that the
low-level equalization process might have emphasized. Other
controls include a stereo link switch and adjustable output level.
The user adjustments described above make it possible to
emphasize ambience, lift harmonics, and bring out otherwise
inaccessible details—all without compressing or limiting
transients, increasing overall level, or disturbing the overall
sense of dynamics.
User adjustments for selectively boosting low-level signals allow
broadcasters to tailor the sound for their station, whatever the
format. It conveys all the detail of the original source material
while eliminating the over-processed sound that can fatigue
listeners. When used in conjunction with a conventional
compressor/limiter, the Spectral Processor adds greater
punch, presence, clarity, and loudness to broadcast signals.