8760 S. Sandy Pkwy.
Sandy, Utah 84070
Phone (801) 568-7660
Fax (801) 568-7662
Int’l Fax (801) 568-7583
http://www.dbxpro.com
A Harman International Company
®
1231
Graphic Equalizer
20
25
31.5
4
0
5
0
6
3
8
0
500
400
315
250
1.6k
1.25k
1k
800
5k
4k
3.15k
2.5k
16k
12.5k
10k
8k
6.3k
20k
2k
630
100
125
160
200
RANGE
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
INPUT
GAIN
dB
-12
0
+12
+/-6
+/-15
CLIP
+18
+10
0
-10
RANGE
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
INPUT
GAIN
dB
-12
0
+12
+/-6
+/-15
CLIP
+18
+10
0
-10
0
-15
+15
0
-15
+15
0
-6
+6
0
-6
+6
The dbx 12 Series were designed to meet the needs of the most demanding sound
reinforcement environments, while offering the simplicity of straightforward controls.
The 1231 provides standard features like dual-channels, 31 1/3 octave bands, ISO
frequency centers, +/- 12 dB input gain range, and switchable 40Hz/18 dB per octave low-
cut filters, but also includes other insightful features. These include 45 mm faders;
sele/-6dB or +/-15dB boost/cut range for precise gain adjustments; XLR, barrier
strip, and 1/4” TRS connectors for installation ease; balanced inputs and outputs for quiet
operation; and chassis/signal ground lift capabilities for quick hum isolation. The
visionary design of the dbx 12 Series makes your job easier.
The dbx 12 Series Equalizers were precision engineered to provide years of maintenance-
free operation in any application. The magnetically isolated transformer, electronically
balanced/unbalanced inputs and servo balanced/unbalanced outputs, RF-filtered inputs
and outputs, and power-off hard-wire relay bypass with 2 second power up delay were
steps our engineers took to ensure compatibility for all installations. Only the best
components were utilized, yielding a 10Hz to 50kHz frequency response, greater than
90dB SNR (ref +4dBu), less than 0.005% THD +Noise (1kHz at +4dBu), and
interchannel crosstalk of less than -80dB from 20Hz to 20kHz. All this attention to detail
is contained in a 3U steel/aluminum chassis. It’s no wonder that dbx has been a leader in
the industry for over 25 years.
18-1779-A 07/99
• Switchable Boost/Cut range between ±6dB and ±15dB
• Electronically balanced/unbalanced inputs
• Servo balanced/unbalanced outputs
• RF filtered inputs and outputs
• XLR, Barrier Strip, and 1/4" TRS connectors
• -12dB/+12dB input gain range
• 18dB/octave 40Hz Bessel low-cut filter
• Chassis/signal ground lift capability
• Internal power supply transformer
• Power-off hardwire relay bypass with 2-second power-up delay
