8
Ch. 2
Ch. 1
UF-2
EX4000
(stereo mode)
Ch. 2
Ch. 1
UF-2
EX2500
(parallel mode)
Ch. 2
Ch. 1
UF-2
EX4000
(bridged mode)
Ch. 1:
Ch. 2
LP @ 150 Hz; HP @ 20 Hz
Bypassed
UF-2: Subwoofer
Ch. 1:
Ch. 2
LP @ 1000 Hz; HP @ 150 Hz
LP @ 1000 Hz; HP @ 150 Hz
UF-2: Woofers
Ch. 1:
Ch. 2
LP @ 5 kHz; HP @ 1000 Hz
LP @ 20 kHz; HP @ 5 kHz
UF-2: Mids & Highs
Subwoofer
The subwoofer subsystem in the example is driven
by a bridged amplifier. Channel 1 of the UF-2 in this
amplifier is set with the high-pass filter at 20 Hz (for
subsonic filtering) and the low-pass at 150 Hz,
which is the crossover point to the woofers. Chan-
nel 2 of the UF-2 is bypassed.
Woofer
The woofers are driven by an amplifier operating in
the parallel mode. Both channels of its UF-2 are set
with the high-pass filter at 150 Hz (the crossover
point from the subwoofers) and the low-pass filter at
1 kHz.
Midrange and High Frequencies
The remaining speakers are driven by the same
amplifier: the mids by channel 1, and the highs by
channel 2. The settings for channel 1 of the UF-2
are: high-pass at 1 kHz (the crossover from the
woofers) and low-pass at 5 kHz (the crossover
point to the high-frequency drivers).
Channel 2 of the UF-2 is set for high-pass at 5 kHz.
For ultrasonic protection, the low-pass is set at 20
kHz.
Figure 9—Multiple amplifiers with UF-2s,
set up for 4-way crossover operation
V. INSTALLATION
Installing the UF-2 requires PC board soldering skills, so only qualified service technicians should attempt
it. Any authorized QSC service center—or, for an additional installation fee, the QSC factory service
center—can perform the installation.
The UF-2 installs on the amplifier input PC board of any QSC EX Series amplifier. Some older EX amplifiers
may require an upgrade to the current input board. Contact the QSC Service Department for details on
compatibility with older EX amplifiers.
When installed, the UF-2 settings and adjustments are not externally adjustable; this can prevent tampering
by unauthorized users.
Tools and materials you will need:
Soldering iron
Desoldering iron or other suitable desoldering equipment
Phillips screwdriver
Wire cutters
Rosin-core solder
Do not use desoldering braid because it may damage the Mini-Slot socket solder pads on the input board,
and it also might not adequately remove solder.
