JBL Synthesis
PCM Effects and Parameters
44
SURROUND ROLLOFF allows the high frequencies of the rear
channels to be attenuated with the same detection circuitry as that
described for the Soundstage control. The attenuation is quite attractive
on many music and broadcast sources that were not mixed for surround.
When a surround source is detected, these filters are removed, so the
rear speakers can reproduce surround events with full bandwidth. This
control should be set high enough to give presence and airiness to the
rear sound without placing distracting instrumental overtones or other
sounds behind you. The settings also affect the side outputs.
SURROUNDS selects the type of surround decoding used by the
SDP-3. STEREOPHONIC provides extraction of five channels of
surround information from a standard 4-2-4 matrix-encoded soundtrack
(Dolby Surround, Ultra*Stereo, etc.) The drama of this effect is depen-
dent on the source material and is most noticeable with strong stereo
music soundtracks. The DECORRELATED setting electronically alters
the monaural surround channel to provide added spaciousness and
envelopment.
VOCAL ENHANCE boosts vocals in the center channel. By targeting
specific frequencies, it can boost only vocals, without raising the entire
center channel level (which would alter the output balance achieved
during calibration).
