JBL Decade L36 - Page 9

performance characteristics in a reverberation-free
environment. Since most listening rooms possess
varying degrees of reverberation, some adjustment of
the controls is usually preferred.
The loudspeaker system should be adjusted while
reproducing normal program material with the
amplifier tone controls set at the middle (generally
referred to as "flat") position. Begin by placing both of
the loudspeaker system controls at the reference level
and listening to a variety of program material long
enough to become accustomed to the system's
performance.
After the ear has become attuned to the "0" setting,
evaluate the presence and brilliance qualities of the
loudspeaker's performance. The most valid evaluation
will be obtained using various types of material played
monaurally. (This can be accomplished in stereo or
quadraphonic installations by setting the amplifier mode
control for monaural reproduction and using the balance
control to select the individual loudspeaker system to be
adjusted.) The evaluation should be made while seated
in the normal listening position.
To arrive at the specific setting for each of the
loudspeaker system controls, proceed as follows:
1. Set the Presence control at "0" and rotate the
Brilliance control to the extreme left of its travel. This
will attenuate high frequency performance so that the
ear will perceive only the balance between the low
frequency loudspeaker and the midrange transducer.
2. If midrange material —such as violin, piano, or
guitar —seems too close or overemphasized, reduce the
setting of the Presence control by rotating it to the left.
Conversely, if midrange material seems too distant,
increase the output of the midrange transducer by
rotating the control clockwise.
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Presence and Brilliance controls are conveniently located
on the front of the enclosure, behind the removable grille
assembly.