Behringer DCX2496 Quick Start Tips page 2

In general the closer you bring the speakers out towards the listening position, the deeper
the sound stage. However there suddenly comes a point where you really notice that the
speakers are too close because the sound locks into two distinct sound sources. Also,
note that for side-seating listeners (such as in HT applications) you should not bring the
speakers out too far, because this effect is exaggerated off axis.
Symmetrical placement of your stereo subwoofers will eliminate all even-order room
modes. Typically you will be left with one primary odd-order room mode, which you
can trap with a single parameter EQ filter. For symmetrical setup in an overall
symmetrical room layout, start with either analog or digital Symmetric preset. The DCX
also comes preloaded for Quadrature Bass. This is a special alignment to smooth in-
room bass response for troublesome or non-symmetrical rooms or non-symmetrical
setup. Typically the left subwoofer is LR 24 LP filter, 90-degree phase, while the right
subwoofer is But 18, in phase. These settings are normal, and do not indicate a
programming error. Use this alignment whenever you experience extra trouble with
room modes, as it will eliminate most odd-order room modes.
Bass level varies from room to room, and is very subjective from person to person.
Adjust the bass level with the sliders for channels 1 & 4. Set the level by ear, or with
measurements, such as via Radio Shack SPL meter and Stereophile Test CD 2 or 3. You
may also use the preprogrammed bass shelf EQ on the input channels, as this operates
over a wider band than does just the subwoofer alone.
It is best to adjust for room/system/personal-preference by using global EQ on channels
A,B,C. Do not implement these types of EQ adjustments directly into the output channel
EQ's. Your DCX comes preloaded with bass shelving and treble parametric EQ. You
may change the center frequency, level, and Q to preference.
With a good precision measurement system, you can locate and compensate for room
bass modes. Again there is preprogrammed EQ for trapping a bass mode under the input
channel EQ's. (The Stereophile test CD and RS meter are not precise enough to properly
address room modes.)
It is best to patiently continue to optimize the bass controls until you arrive at a setting
that you feel is right under most or average conditions. With optimized BESL bass units,
you will find that even 1dB level changes are now audible. However, you will also
discover that the bass level varies greatly among audio recordings and video programs.
For example, one TV station or a particular show will have louder bass than another.
In general, the bass performance is best when you stop noticing it! Usually, when you
notice that you like the bass, it is still set too high. But when you notice the impact of the
bass as it integrates with the entire sound, then it is set right.
BESL monitors are designed for THX bass response and are compatible with the Small
Speaker setting in HT preamp/processors. However, I have found the THX 80Hz
subwoofer/monitor crossover frequency requirement to be less than optimal for typical
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