8760 S. Sandy Pkwy.
Sandy, Utah 84070
Phone (801) 568-7660
Fax (801) 568-7662
Int’l Fax (801) 568-7583
customer@dbxpro.com
http://www.dbxpro.com
A Harman International Company
0
18-1773-A 01-99
Let’s take a look at the construction features of the dbx 234XL. At first glance you’ll notice the units are great looking, and as you turn the controls something else becomes apparent; these units are extremely well built. The controls
exude great precision, and the feel is a solid “click”. Also, when you open the box, you won’t find the external power
supply that accompanies most processors in this price range. That’s because we know how difficult external power
supplies can be to work with and even though it costs a little more we put the high quality power supply right in the
unit. All the inputs and outputs are balanced XLR connectors that are screwed directly to the chassis. This connecting of the jacks insures that even if someone steps on a cable plugged into the unit, it’s not going to tear up the
circuit board inside. All dbx crossovers feature Linkwitz-Riley 24 dB per octave filters, the professional standard, but
then again, what did you expect?
Via two switches on the back panel you first select whether you’re operating your system in stereo 2-way, 3-way or
mono 4-way. Another back panel switch also selects whether or not you want to mono sum the LF (subwoofer) out.
(Most systems that use a subwoofer are mono summed to take advantage of amplifier power and because low frequencies are non-directional.) Back panel switches allow you to select the range of the crossover frequencies individually for both channels. The crossover frequency controls have a green LED that indicates the X10 switch on the
back panel is activated (we wouldn’t make you check the switch position on the back every time you wonder where
it’s set). All these switches are on the back panel because it could be disastrous if you were to change them mid-program. On the front panel you’ll notice there are LEDs that indicate whether the unit is in mono or stereo mode. Each
channel has an input gain control for proper level setting. There’s a recessed 40 Hz low cut (HPF) on each channel
to remove unwanted low frequencies. Both the low and high outputs on each channel have a gain control ranging
from -∞ to +6dB, to allow muting of individual outputs and for level matching. Also, these outputs each have phase
reverse switches that’ll help get you out of a bind without having to reconfigure your system. These phase reverse
switches may be internally reconfigured as mute switches.
You’ll get great performance, all the features you’d expect from a professional product, and the knowledge that
you’re buying a processor from the people that have been producing the world’s finest processors for over 20 years.
The technology that made us famous brings you a dbx crossover which has been tested to the highest professional
standards at a price that’s just too low to admit!
• XLR differentially balanced ins and outs
• Mode switches for mono 4-way or stereo
2-way/3-way operation
• Low frequency summed (subwoofer) output
• x10 range switch on both channels
• 40 Hz high pass (low cut) filter both
channels
• Phase reverse switch on all outputs
• Individual level controls on all band outputs
• 24dB per octave Linkwitz-Riley filters (the
professional standard)
• Stereo/Mono status LEDs indicate the
selected mode
• dbx 2 year parts and labor as standard
• CSA NRTL/C approved
• CE compliant
-10
-30
0
-10
-30
0
-10
-30
6.8k
3.5k
2.4k
1.4k
700
x10
350
240
140
70 680
0
-6 +6
0
-10
-30
0
-10
-30
INV INV INV INV INV INV
0
-10
-30
6.8k
3.5k
2.4k
1.4k
700
x10
350
240
140
70 680
40 Hz 40 Hz
CHANNEL ONE CHANNEL TWO
0
-6 +6
+6
dB
GAIN
-
+6
dB
GAIN
-
+6
dB
GAIN
-
9.6k
Hz
XOVER FREQ
450
960
Hz
XOVER FREQ
45
+12
dB
GAIN
-12
+6
dB
GAIN
-
+6
dB
GAIN
-
+6
dB
GAIN
-
9.6k
Hz
XOVER FREQ
450
960
Hz
XOVER FREQ
45
+12
dB
GAIN
-12
MID OUTPUT HIGH OUTPUT
HIGH-MID OUTPUT HIGH OUTPUT
MID/HIGH LOW OUTPUT
HIGH-MID/HIGH
STEREO
MONO
MID OUTPUT HIGH OUTPUT INPUT LOW CUT LOW/MID
LOW-MID OUTPUT
LOW OUTPUT
LOW OUTPUT
MID/HIGH
LOW-MID/HIGH-MID
LOW/MID
LOW/LOW-MID
LOW CUT
LOW CUT
INPUT
INPUT
®
A Harman International Company
FOR MORE INFORMATION CONTACT:
dbx Professional Products • 8760 S. Sandy Pkwy. • Sandy, Utah 84070
Phone (801) 568-7660 • Fax (801) 568-7662 • Int’l Fax (801) 568-7583
customer@dbxpro.com • http://www.dbxpro.com
The crossover shall be selectable for stereo 2-way,
3-way or mono 4-way operation, each stereo channel having input gain and low, mid, and high output gain controls, a switchable low-cut filter, two
variable crossover frequency controls, and low,
mid, and high output phase invert switches on the
front panel. Rear-panel input connectors shall be
XLR balanced/unbalanced with input impedance
of not less than 50 kΩ balanced and 25 kΩ unbal-
anced and maximum input level of not less than
+21 dBu. Rear-panel low, mid, and high output
connectors shall be XLR impedancebalanced/unbalanced with output impedance of no
more than 200 Ω balanced and 100 Ω unbalanced
and maximum output level of not less than +21
dBu into 2 kΩ or greater. Input gain controls shall
be variable from -12 to +12dB and output gain
controls shall be variable from -∞ to +6dB. Each
output’s phase invert switch shall have an LED to
indicate inverted phase and shall be internally
selectable to change the invert function to a mute
function. Low-cut filters shall be 12dB/octave
Butterworth type at 40 Hz and shall be activated by
recessed switches with LEDs indicating active status. Low/mid frequency controls shall be variable
from 45 to 960 Hz and shall be scaleable to 450 Hz
to 9.6 kHz via rear-panel “x10” frequency range
switches with front-panel LEDs indicating “x10”
status, and mid/high frequency controls shall be variable from 450 Hz to 9.6 kHz. A rear-panel LF sum switch shall sum the pre-output gain signals
of both channels’ low-frequency outputs and route the combined signal to channel 1’s low output and shall disable channel 2’s low phase invert LED.
A rear-panel mode switch shall select between stereo 2-way, 3-way, and mono 4-way operation with front-panel LEDs indicating the selected mode.
Mono operation shall convert channel 1’s low/mid and mid/high and channel 2’s mid/high crossover frequency controls to low/low-mid, lowmid/high-mid, and high-mid/high controls respectively, and shall convert channel 1’s low and mid outputs and channel 2’s mid and high outputs to
low, low-mid, high-mid, and high outputs respectively, while channel 1’s input, input gain, and low-cut filter shall remain active. All other functions
shall be inactive and the mono mode shall disable LEDs for all inactive functions.
Frequency response shall be 3 Hz to 90 kHz or greater and signal-to-noise ratio shall be not less than 92 dB on any output in any mode. THD+Noise
shall be less than 0.004% at +4 dBu and less than 0.04% at +20 dBu from 20 Hz to 20 kHz and interchannel crosstalk shall be no greater than -80 dB
from 20 Hz to 20 kHz. The unit shall operate from a power source of 100 VAC 50/60 Hz to 120 VAC 60 Hz for a domestic unit and 230 VAC 50 Hz
for a european unit via IEC type AC cable and shall consume no more than 15 W. The size of the 1U high, full rack width unit shall be
1.75" H X 19" W X 6.9" D (4.4cm x 48.3cm x 17.5cm) with a net weight of 4.0 lbs. (1.8 kg) and a shipping weight of 5.8 lbs. (2.6 kg). The crossover
shall be a dbx 234XL.
dbx engineers are constantly working to improve the quality of our products. Specifications are, therefore subject to change without notice.
STEREO 2-WAY / 3-WAY / MONO 4-WAY CROSSOVER
234XL
INPUT:
Connectors: XLR
Type: Electronically balanced/unbalanced, RF fil-
tered
Impedance: Balanced > 50 kΩ, unbalanced > 25 kΩ
Max Input Level: > +21 dBu balanced or unbalanced
CMRR: > 40 dB, typically > 55 dB at 1 kHz
OUTPUT:
Connectors: XLR
Type: Impedance-balanced/unbalanced, RF fil-
tered
Impedance: Balanced 200 Ω, unbalanced 100 Ω
Max Output Level: > +21 dBu balanced/unbalanced into 2 kΩ
or greater
PERFORMANCE:
Bandwidth: 20 Hz to 20 kHz, +0/-0.5 dB
Frequency Response: < 3 Hz to > 90 kHz, +0/-3 dB
Signal-to-Noise: Ref: +4 dBu, 22 kHz measurement band-
width
Stereo Mode: Mono Mode:
Low Output: > 94 dB > 94 dB
Low-Mid Output: > 94 dB
Mid Output: > 93 dB
High-Mid Output: > 92 dB
High Output: > 92 dB > 92 dB
Dynamic Range: > 114 dB, unweighted, any output
THD+Noise: < 0.004% at +4 dBu, 1 kHz
< 0.04% at +20 dBu, 1 kHz
Interchannel Crosstalk: < -80 dB, 20 Hz to 20 kHz
CROSSOVER FREQUENCIES:
Stereo Mode:
Low/Mid: 45 to 960 Hz or 450 Hz to 9.6 kHz (x10
setting)
Mid/High: 450 Hz to 9.6 kHz
Mono Mode:
Low/Low-Mid: 45 to 960 Hz or 450 Hz to 9.6 kHz (x10
setting)
Low-Mid/High-Mid: 450 Hz to 9.6 kHz
High-Mid/High: 450 Hz o 9.6 kHz
Filter Type: Linkwitz-Riley, 24 dB/octave, state-vari-
able
FUNCTION SWITCHES:
Front Panel:
Low Cut: Activates 40 Hz Butterworth, 12 dB/octave
high-pass filter, one switch per channel.
Phase Invert: Inverts the phase at the output, one switch
per output.
Rear Panel:
x1 / x10: Multiplies the low-mid (mono: low/low-mid)
crossover frequency range of the frontpanel markings by a factor of 1 or 10, one
switch per channel.
Mode: Selects stereo 2-way, 3-way or mono 4-
way operation and disables all LEDs for
controls that are non-functional in the
mono mode.
LF Sum: Selects normal (stereo) or mono-summed
low frequency operation and disables Ch
2’s low output phase invert LED to indicate that this output is not operational in
the LF sum mode.
INDICATORS:
Stereo Operation: Green LED
Mono Operation: Yellow LED
Low Cut: Red LED per channel
x10: Green LED per channel
Phase Invert: Red LED per output (3 per channel)
POWER SUPPLY:
Operating Voltage: 100-120 VAC 50/60 Hz; 120 VAC 60 Hz
230 VAC 50 Hz
Power Consumption: 15 Watts
Mains Connection: IEC 320 receptacle
PHYSICAL:
Dimensions: 1.75" H X 19" W X 6.9" D (4.4cm x
48.3cm x 17.5cm)
Weight: 4.0 lbs. (1.8 kg)
Shipping Weight: 5.8 lbs. (2.6 kg)
Note: Specifications subject to change.
CHANNEL ONE CHANNEL TWO
0
-6 +6
-12
dB
GAIN
INPUT
INPUT
+12
240
1.4k
350
140
70 680
40 Hz 40 Hz
LOW CUT
LOW CUT
45
Hz
XOVER FREQ
LOW/LOW-MID
LOW/MID
700
x10
960
450
XOVER FREQ
LOW-MID/HIGH-MID
MID/HIGH
-10
2.4k
3.5k
-30
6.8k
+6
9.6k
-
Hz
dB
GAIN
LOW OUTPUT
LOW OUTPUT
-10
-30
0
INV INV INV INV INV INV
+6
-
dB
GAIN
LOW-MID OUTPUT
MID OUTPUT HIGH OUTPUT INPUT LOW CUT LOW/MID
-10
-30
0
0
+6
-
dB
GAIN
MONO
STEREO
-6 +6
-12
0
+12
dB
GAIN
240
140
70 680
45
Hz
XOVER FREQ
1.4k
350
700
x10
960
2.4k
3.5k
-30
6.8k
9.6k
450
-
Hz
XOVER FREQ
HIGH-MID/HIGH
dB
GAIN
MID/HIGH LOW OUTPUT
+6
-10
-10
-30
0
-
dB
GAIN
HIGH-MID OUTPUT HIGH OUTPUT
MID OUTPUT HIGH OUTPUT
-10
-30
0
+6
0
+6
-
dB
GAIN
®