Product Overview

The DBX 231s is a dual 31-band graphic equalizer from the 2 Series, designed for live sound reinforcement, touring, and installed audio applications that require precise 1/3-octave frequency control in a compact 2U rack-mount format. As a portable dual-channel graphic EQ with Constant Q filter response and 112 dB dynamic range, the DBX 231s graphic equalizer delivers professional signal processing at a practical price point for touring engineers, system rental companies, and smaller installed sound projects. Available at Creation Networks.

Product Description

The DBX 231s provides two independent channels of 31-band 1/3-octave graphic equalization in a 2U chassis suited for both touring racks and permanent equipment installations. Each channel features 31 ISO-centered frequency bands with 30mm faders covering the full audio spectrum from 20 Hz to 20 kHz. The Constant Q filter design maintains filter bandwidth relative to the amount of boost or cut applied, preventing the bandwidth narrowing that occurs with proportional Q equalizers at high boost or cut settings, and delivering more predictable equalization behavior across different gain settings. The 2 Series design uses electronically balanced XLR and TRS inputs and outputs, and the universal power supply accepts 100-240V at 50/60 Hz for international touring use without voltage switching. A high-pass filter at 40 Hz with an 18 dB/octave slope removes sub-bass content, and the front-panel EQ bypass switch allows quick comparison between the processed and flat signal. Dynamic range exceeds 112 dB, A-weighted, with THD+Noise less than 0.005% at +4 dBu, and the frequency response is flat within +0.5/-1 dB from 20 Hz to 20 kHz at unity gain. The 231s is a straightforward dual 31-band graphic EQ appropriate for monitor system equalization, main system room correction, and send-return equalizer applications in live sound systems.

Key Features

• Dual 31-Band 1/3-Octave Constant Q EQ – Two independent channels with ISO-centered frequency bands and Constant Q filter behavior across all boost/cut settings.
• 112 dB Dynamic Range – A-weighted dynamic range appropriate for professional live sound and installed audio applications.
• XLR and TRS I/O – Electronically balanced XLR and TRS connectors on inputs and outputs for connection to mixing consoles, amplifiers, and system processors.
• Universal Power Supply – Accepts 100-240V at 50/60 Hz for use in international touring and rental applications without voltage switching.
• 40Hz High-Pass Filter – 18 dB/octave slope removes sub-bass content that can reduce amplifier headroom and cause loudspeaker overload.
• Front-Panel EQ Bypass – One-touch bypass for direct comparison between processed and unprocessed signal during system setup.
• 2U Rack Format – Standard 19-inch rack mounting in a 2U chassis compatible with touring racks and permanent equipment installations.
• Constant Q Filter Design – Maintains consistent filter bandwidth regardless of boost/cut depth for predictable equalization behavior.

Typical Applications

• Live music venue
• House of worship
• Multi-purpose room
• Auditorium
• Monitor system equalization
• Rental and touring production

Technical Specifications

Frequently Asked Questions

What is Constant Q equalization and why does it matter?Constant Q equalization maintains a consistent filter bandwidth (Q) regardless of how much boost or cut is applied. In a proportional Q design, the bandwidth narrows as the boost or cut amount increases. Constant Q behavior gives the DBX 231s more predictable and consistent frequency shaping across all fader positions, which is useful for live sound applications where repeatable results are important.Does the DBX 231s have transformer balanced outputs like the 12 Series equalizers?No. The 231s uses electronically balanced inputs and outputs rather than transformer balanced connections. Electronic balancing provides equivalent noise rejection for most applications but does not provide the galvanic isolation that transformer balancing offers. For installations where ground loop isolation is a requirement, the DBX 1231 with transformer balanced I/O is the appropriate choice.Can the DBX 231s be used on touring productions outside North America?Yes. The universal power supply in the 231s accepts 100-240V at 50/60 Hz, making it compatible with power standards across North America, Europe, and most other regions without a voltage switching procedure or external transformer.What is the difference between the DBX 231s and the DBX 215s?The 231s has 31 bands of 1/3-octave equalization per channel, providing finer frequency resolution for detailed room correction. The 215s has 15 bands of 2/3-octave equalization per channel, which applies broader adjustments suitable for general voicing and room mode correction. Both units share the same 2 Series format, Constant Q filter design, and universal power supply.How should the 231s be positioned in a live sound signal chain?The 231s is commonly inserted in the main output of the mixing console before the amplifier or crossover, or in the auxiliary send outputs used for monitor mixes. It can also be used in the insert return of a mixing console channel or group for channel-specific frequency correction.What is the maximum boost or cut available on each band of the DBX 231s?Each of the 31 bands provides plus or minus 12 dB of boost or cut, which is sufficient for most room correction and system voicing tasks in live sound and installed audio applications.