Setting The Input Sensitivity; Functions On Switch Group 1 (Tone Controls) - Genelec DSP 8260A Operating Manual

Setting the Input Sensitivity

The loudspeaker level sensitivity functions for both analog and
digital input. The sensitivity can be matched by adjusting the ro-
tary Level control together with the System Level switches lo-
cated in the switch group 2. (switches 6 and 7). The switches
provide attenuation levels of -10 dB (sw. 6 ON), -20 dB (sw. 7 ON)
and -30 dB (both switches ON) The combined attenuation ranges
from 0 to -42 dB.
Figure 6. System
Level rotary control
Functions On Switch Group 1
(Tone Controls)
Switch group 1 (the upper switch group) comprises the tone
controls that can be used to adjust the frequency response of
the system in stand-alone mode to match the acoustic environ-
ment.
Figure 7. Switch Group 1
Please note that the GLM Loudspeaker Controller allows a much
more versatile and precise set of controls to be used and sup-
ports the fully automatic system alignment feature, the Genelec
AutoCal. Use the tone control switches on the loudspeaker only
if a GLM is not available for for calibrating the system.
The controls are labelled "TREBLE TILT", "BASS TILT", "BASS
ROLL-OFF" and "DESKTOP". The factory settings for these controls
are all "OFF" to give a flat anechoic response. Note that these con-
trols have no effect when switch 1 "STORED/MANUAL CONTROL"
on switch group 2 is set to "STORED" or when the loudspeaker is
connected to the Genelec loudspeaker control network.
Bass Roll-Off Control
Bass Roll-Off control (switches 1 and 2) affects the low frequency
roll-off of the loudspeaker and attenuates its output near the cut-
off frequency. Attenuation levels of -2 dB (sw. 1 ON), -4 dB (sw. 2
ON) or -6 dB (both switches ON) can be selected.
Bass Tilt Control
The Bass Tilt control switches (swiches 3 and 4) offer three atten-
uation levels for the bass response below 800 Hz, usually neces-
sary when the loudspeakers are placed near room boundaries.
The attenuation levels are -2 dB, -4 dB and -6 dB.
6
Loudspeaker Treble
Mounting Position Tilt
Flat anechoic None
response
Free standing in None
a damped room
Free standing in None
a reverberant room
Near field on
None
a reflective surface
In a corner
None
Table 1. Suggested Tone Control settings for some typical loud-
speaker placement positions.
Desktop Low Frequency Control
The desktop low frequency control (switch 5) attenuates the bass
frequencies around 160 Hz by 4 dB. This feature is designed to
compensate for the boost often occurring at this frequency range
when the loudspeaker is placed upon a meter bridge, table or
similar reflective surface.
Treble Tilt Control
Treble Tilt control (switches 6 and 7) allows adjusting the treble
response above 5 kHz by +2 dB, -2 dB or -4 dB, which can be
used for correcting an excessively bright or dull sounding system
or to compensate for high frequency level loss if the loudspeaker
is placed behind a screen.
An acoustic measuring system such as MLSSA or WinMLS is
recommended for analyzing the effects of the adjustments, how-
ever, careful listening with suitable test recordings can also lead
to good results if a test system is not available. Always start ad-
justment by setting all switches to "OFF" position. Measure or lis-
ten systematically through the different combinations of settings
to find the best frequency balance. See Table 1 for some typical
settings in various situations.
Functions On Switch Group 2
Figure 8. Switch Group 2
Stored / Manual Ctrl
This allows the selection between two basic methods of control-
ling the loudspeaker in the stand-alone mode. "MANUAL CTRL"
refers to controlling the loudspeaker using the controls on the
loudspeaker's back panel. The "STORED" refers to using settings
stored inside the memory of the loudspeaker. These settings are
made using the GLM and the GLM Control Network. There is
additional functionality compared to that offered by the room re-
sponse correction switches on the back panel.
Bass Bass Desktop
Tilt Roll-Off
None None None
-2 dB None None
-4 dB None None
-2 dB None -4 dB
-4 dB -4 dB None