Lexicon 300L - REV Owner's Manual page 82

BAL implements a sine/cosine balance adjustment. Balance is smoothly ad-
justed over a wide range, with excellent resolution in the critical area around
zero. The display indicates the actual channel gains as the control is varied.
ROT is similar to BAL, but it treats stereo information somewhat differently. Any
signal panned to the center (mono) will be treated by ROT exactly as it would be
treated by BAL. However, if a signal is panned full right and the control is moved
toward the right, instead of simply being attenuated (as BAL would do) the right
channel is inverted in phase and added to the left channel. A stereo image
appears to rotate when this control is used. Ambient information is preserved,
and both channels appear to retain equal loudness.
If stereo material is recorded with a coincident pair of figure-of-eight micro-
phones, moving the ROT slider is exactly equivalent to rotating the microphone
pair. Other microphone arrays and multimicrophone setups do not rotate
perfectly, but using this control is frequently preferable to simply adjusting
balance. The display shows the actual channel gains for a continually panned
source.
BAS is a 6dB/octave shelving EQ control with a range of +6 dB boost and -18dB
cut. It moves in .5 dB steps from +6 to -6 dB. The crossover point is adjusted with
BXO. BAS acts on both stereo channels equally.
TRB is a 6 dB/octave shelving EQ controls with a range of +6 dB boost and -18dB
cut. It moves in .50 dB steps from +6 to -6 dB. The crossover point is adjusted
with TXO. TRB acts on both stereo channels equally.
SPEQ sets the amount of a crossfeed between channels. The signal first goes
through a 6 dB/octave low-pass filter whose frequency is set with BXO.
When SPEQ is set positive (above 0) the crossfeed has a negative sign. When
SPEQ is set negative (below 0), the crossfeed has a positive sign. When the
control is set to either maximum or minimum, the gain in the crossfeed circuit is
unity.
The result of this control is to change the separation of low frequency stereo
signals. When the control is raised, low frequencies in the sum (mono) channel
are reduced, and low frequencies in the difference (stereo) channel are raised.
With the control at maximum, low frequency mono signals are completely
removed. This represents an extreme setting which should seldom be needed
in practice.
With material which has stereo bass information, or which contains some
reverberation, the effect of raising SPEQ is to increase the sense of spacious-
ness and depth of the sound. It is particularly useful on material recorded with
panpots, or coincident and semi-coincident microphone technique.
When most of the bass in a recording is in the sum (mono) channel, raising
SPEQ may reduce the bass level. This effect can be compensated for by raising
the overall bass level with BAS. Since both controls use the same BXO setting,
The Algorithms and their Parameters
BAL (Balance)
ROT (Rotate)
BAS (Bass EQ)
TRB (Treble EQ)
SPEQ (Spatial EQ)
4-17