dbx 2231 User Manual

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
• dbx’s revolutionary Type III™
Noise Reduction system, which
increases S/N ratio by up to
20dB
• PeakPlus™ limiting technology
with threshold range from 0dBu
to +24dBu (off)
• Two 31-band, 1/3-octave chan-
nels with switchable boost/cut
ranges of +
6 or +15 dB
• +
12 dB input gain range
• XLR, Barrier strip, and 1/4"
inputs
• 4-segment LED ladders for mon-
itoring of gain reduction and
output levels–the most compre-
hensive visual feedback available
• Exceptional sound quality
• dbx’s unmatched engineering and
construction standards
2231
Equalizer/Limiter
with TYPE
III
NR
20 25 31.5 40 50 63 80 500400315250 1.6k1.25k1k800 5k4k3.15k2.5k 16k12.5k10k8k6.3k 20k2k630100 125 160 200
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE
III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0OFF
+20+5
+15+10
+/-6
+/-15
CLIP
13610+18+100-10
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE
III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0OFF
+20+5
+15+10
+/-6
+/-15
CLIP
13610+18+100-10
0
-15
+15
0
-15
+15
0
-6
+6
0
-6
+6
2231
DUAL CHANNEL 31 BAND
EQUALIZER WITH
TYPE III™ NOISE REDUCTION
2231
DUAL CHANNEL 31 BAND
EQUALIZER WITH
TYPE III™ NOISE REDUCTION
2231
DUAL CHANNEL 31 BAND
EQUALIZER WITH
TYPE III™ NOISE REDUCTION
2231
DUAL CHANNEL 31 BAND
EQUALIZER WITH
TYPE III™ NOISE REDUCTION
®
With a prestigious heritage extending back to our heralded 30 Series equalizers, the dbx
2231 easily lives up to the reverred dbx reputation. Besides including two 31-band chan-
nels of 1/3-octave equalization, the 2231 empowers you with flexible features like our
PeakPlus™ limiter circuit, and our amazing Type III™ Noise Reduction system. It also
includes +12 dB input gain range; switchable + 6 or + 15 dB boost/cut range; XLR,
Barrier strip, and 1/4'' inputs; nonconductive nylon sliders; and an intuitive user interface
with comprehensive output and gain reduction metering. As always, the inevitable result
of our meticulous attention to detail and top-quality componentry is exceptional sound,
performance, and reliability.
The most revolutionary feature of the 2231 is our proprietary Type III™ Noise Reduction
system, which enables you to boost signal-to-noise ratios by up to an incredible 20dB.
The result of this instant encode/decode process is that you’re no longer forced to employ
drastic EQ settings in effort to reduce system noise. Instead, you’re freed to dedicate all
EQ bands to the most important thing, the music. Further , our PeakPlus™ limiter tech-
nology allows you to easily safeguard your gear against hazardous dynamic sur ges in
program material. In addition to these formidable tools, the 2231’ s front panel provides
at-a-glance insight as to gain reduction and output level status via its four-stage LED lad-
ders. With such power and finesse built into such a reasonably priced package, it’ s easy
to see why dbx 20 Series equalizers are relied upon by studio and touring professionals
the world over. With such affordable quality, there’s no longer any excuse for compro-
mising your sound.
18-1720-C 12/99

dbx 2231 Specifications

General

Frequency Range	20 Hz to 20 kHz
Filter Type	Constant Q
Input Connectors	XLR, 1/4" TRS
Input Type	Balanced/Unbalanced
Output Connectors	XLR, 1/4" TRS
Output Type	Balanced/Unbalanced
Type	Graphic Equalizer
Frequency Bands	31
Max Input	+21 dBu
CMRR	>40 dB (1 kHz)
Output Impedance	150 ohms
Max Output	+21 dBu
Bandwidth	20Hz - 20kHz
Signal to Noise Ratio	>90dB
Interchannel Crosstalk	<-80dB @ 1kHz
Bypass	Hardwire
Low Cut Filter	Yes, 40Hz
Range	±6dB or ±12dB
Operating Voltage	100-240VAC, 50/60Hz
Power Consumption	15W

Summary

Visionary Design

Product Heritage and Key Features

Overview of the dbx 2231's lineage, including 31-band EQ, PeakPlus limiter, Type III NR, and versatile connectivity.

Revolutionary Engineering

Type III Noise Reduction and PeakPlus Limiter

Details the proprietary Type III NR system for up to 20dB noise reduction and PeakPlus limiter for dynamic surge protection.

Features Overview

Core Feature List

Highlights key features such as Type III NR, PeakPlus limiter, switchable EQ ranges, input gain, connectivity, and LED metering.

Architects' and Engineers' Specifications

Graphic Equalizer Specifications

Details frequency centers, boost/cut ranges, slider travel, input gain controls, bypass functions, and low-cut filter.

Noise Reduction and Limiter Specifications

Covers Type III NR performance, PeakPlus limiter threshold, and gain reduction/output level metering.

Input and Output Connectivity

Specifies connector types, impedance, maximum levels, and filtering for both inputs and outputs.

System Performance Metrics

Outlines bandwidth, frequency response, signal-to-noise, dynamic range, THD+Noise, and interchannel crosstalk.

Power Supply and Physical Dimensions

Details operating voltage, power consumption, mains connection, physical dimensions, and weight.