Parameters used in the 960l algorithms – Lexicon 960L User Manual

Page 78

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Using The Reverb Program

Lexicon, Inc.

5-12

Parameters Used in the 960L Algorithms,

Continued

LvL>L,
LvR>R,
LvL>R,
LvR>L,
LvLF>LF,
LvLF>LS,
LvLF>RF,
LvLF>RS,
LvLS>LF,
LvLS>LS,
LvLS>RF,
LvLS>RS,
LvRF>LF,
LvRF>LS,
LvRF>RF,
LvRF>RS,
LvRS>LF,
LvRS>LS,
LvRS>RF,
LvRS>RS

MidRT

Mix

RefDly

RefLvl

Rolloff

RPreD

Reflection Levels. In many real spaces, distinct reflections and echoes are an important part
of the sound, so many of the 960L's reverbs have reflection delay and echo paths with
appropriate controls.

The Reflection Delays set the delay time. For example, dLF>RS is the delay time in a path from
the Left Front Input, through the diffusor, through a delay of dLF>RS duration, and finally to the
Right Surround Output.

Each of these delay paths has its own level control as well as a master control for all of the
(ErlLvl). The level of the example delay path is set by the related control LvLF>RS.

Midrange Reverberation Time. The basic control for setting the duration in seconds of the
reverberant tail. This is the control that is most like the physical RT60 parameter. The perceived
time will also be affected by RtHicut and Bass. Generally, MidRT should be set to a value of
about 1.2 seconds for small rooms and up to 2.4 seconds or so for halls.

Wet/Dry Mix. Each of Lexicon's factory programs are typically shipped at 100% Wet, and we
recommend controlling the mix at the console, rather than on the LARC2. Where a console is not
available this control can be used to adjust the wet/dry ratio. When a console is being used to
adjust the mix of the reverberation returns, be sure the wet/dry Mix control is set at 100%.
Otherwise the direct path through the 960L will interfere with the direct path through the console
and severe combing will occur.

Reflection Delay (Reverse algorithm only) operates very much like the reflection delays in other
reverbs. In Reverse, it has a particular role, which is to supply the "dry" sound at the end of the
apparently reversed tape. The Reflection Delay is connected to Size. Changes in Size will scale
this delay. See also Reflection Level.

Reflection Level (Reverse algorithm only) operates very much like the levels for reflection delays
in other reverbs. In Reverse, it has a particular role, which is to supply the "dry" sound at the end
of the apparently reversed tape. See also Reflection Delay.

Rolloff (Stereo algorithms only) sets the cutoff frequency of a 6dB per octave low-pass filter at the
output of all reverberation processing. Rolling off high frequencies with this filter can result in more
natural-sounding characteristic. For a shelving characteristic, use Shelf. Rolloff does not affect the
frequency response of the early reflections. See RefHicut.

Rear PreDelay (Surround algorithms only) is an additional predelay that can be added to rear
input path to recreate the effect of the space’s rear wall being farther from the listener than the
front. The total rear-channel predelay is the sum of RvbPreD and RPreD, so the latter’s values are
always preceded by a "+" on the display. E.g., with RPred of +20 and RvbPreD of 100, the onset
of reverberation from the rear will occur 120 msec after the initial acoustical event. For best results
we recommend that the RPreD control be set to values less than 20ms. Greater values tend to
make the reverberation from the rear separately audible from the front reverberation, and the room
seems less natural.

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