dbx 234S - Digital Zone Processor

dbx 234s - Active 2/3-way stereo and 4-way mono crossover with 24 dB/oct Linkwitz-Riley filters

The dbx 234s is an analog crossover designed for bi-, tri-, or 4-way PA systems. Its 24 dB/octave Linkwitz-Riley filter design separates the spectrum into precise bands, sending each power amp/speaker only the range it can reproduce with maximum efficiency, reducing distortion and improving cleanliness. It allows operation in 2-way stereo , 3-way stereo , or 4-way mono (switchable), and includes a summed mono subwoofer output , a 40 Hz low-cut filter , and a x10 switch per channel to expand the crossover ranges.

The 234s version offers differential balanced 1/4” TRS connectivity on inputs and outputs, ±12 dB input gain control , and independent level controls per band for system matching. Each output features phase inversion with an LED indicator, facilitating electrical alignment between channels. With a dynamic range of >106 dB , THD+N < 0.004% (at +4 dBu, 1 kHz), and a response of <3 Hz–>90 kHz , it is a robust and quiet tool for touring, installations, and studios.

Main features

• Operating modes : 2-way stereo , 3-way stereo or 4-way mono selectable by rear switches (Mono/Stereo status LED).
• Crossover filters : Linkwitz-Riley 24 dB/oct (professional standard) for flat acoustic summing.
• Crossover frequency ranges :
  • Low/High Band (2-way) : 45–960 Hz or 450 Hz–9.6 kHz (with x10 ).
  • 3-way stereo : Low/Mid 45–960 Hz (or ×10); Mid/High 450 Hz–9.6 kHz.
  • 4-way Mono : Low/Low-Mid 45–960 Hz (or ×10); Low-Mid/High-Mid and High-Mid/High 450 Hz–9.6 kHz.
• Low Cut at 40 Hz (Butterworth 12 dB/oct) per channel to protect systems and eliminate infra-bass.
• Switchable mono subwoofer output (LF Sum).
• Phase inversion on all outputs (LED per output) and independent level per band for level matching .
• Differentially balanced 1/4” TRS inputs/outputs (impedance balanced outputs).
• x10 switch per channel to expand the adjustment range of the crossover frequencies.
• Audio performance : DR >106 dB , THD+N <0.004% (at +4 dBu), crosstalk < −80 dB (20 Hz–20 kHz), CMRR > 40 dB (typical > 55 dB at 1 kHz).
• Lightweight and reliable 1U construction , suitable for touring and fixed installation.

Product benefits

• More usable pressure and less distortion : Each stage works only in its own band; the system sounds cleaner and has more headroom.
• Simple alignment : phase inversion per track and independent level control to match polarities and sensitivities.
• True versatility : bi-amp, tri-amp or 4-way from the same unit, with optional mono sub and integrated Low Cut.
• Easy integration : Balanced 1/4” TRS connectors and wide crossover ranges (x10) to adapt to any box/driver.

Use cases

• Tri-amplified PA (3-way stereo) for 3-way tops + subs.
• Bi-amplification of 2-way speakers switched to active (2-way stereo).
• 4-way mono systems for large-format sound reinforcement.

Frequently Asked Questions

• How does it differ from the 234xs ? The 234s uses 1/4" TRS connectors ; the 234xs offers XLR connectors . The features and filters are equivalent.
• Can I use a mono subwoofer? Yes. Activate LF SUM to sum the bass from both channels and feed a mono subwoofer.
• What is the x10 switch for? It multiplies the crossover potentiometer range by 10, useful for high frequencies (e.g., 2–6 kHz).
• Is the 234s digital? No. It's analog , with 24 dB/octave Linkwitz-Riley filters.

Description for projects

dbx 234s active crossover ; 2/3-way stereo or 4-way mono modes; 24 dB/oct Linkwitz-Riley filters; crossover ranges: 45–960 Hz (Low) and 450 Hz–9.6 kHz (with x10 ); Low Cut 40 Hz (Butterworth 12 dB/oct) per channel; switchable LF Sum (sub mono); Balanced 1/4” TRS inputs/outputs (electronically balanced inputs; impedance-balanced outputs); ±12 dB input gain ; independent level and phase reverse on each output; performance: BW 20 Hz–20 kHz +0/−0.5 dB , FR <3 Hz–>90 kHz +0/−3 dB , DR >106 dB , THD+N <0.004% (@ +4 dBu, 1 kHz), crosstalk < −80 dB; levels: max. input > +22 dBu, max. output > +21 dBu (≥ 2 kΩ); power supply 100/120/230 V~ , 15 W ; dimensions 44.5 × 482.6 × 175 mm (H × W × D); weight 1.8 kg (shipping 2.6 kg ).