dbx 640m 6x4 Digital Zone Processor

dbx 640m 6x4 Digital Zone Processor

The dbx 640m is a compact yet powerful digital zone processor built for sound operators managing distributed audio across multiple zones and venues. This 19-inch rackmountable unit delivers professional-grade signal processing in a shallow 1.75-inch depth, making it ideal for retrofit installs and tight rack spaces. Its combination of balanced and unbalanced inputs, psychoacoustic processing, and third-party control integration positions it as a reliable tool for managing complex audio environments where independent zone control and real-time metering are non-negotiable.

Signal Path & I/O Architecture

The 640m combines 6 inputs (4 balanced mic/line switchable Euroblock connectors plus 2 unbalanced RCA pairs) with 4 independent outputs, each capable of delivering up to +20 dBu (Euroblock) or +12 dBu (RCA). The dbx Type IV A/D converter exceeds 113 dB dynamic range on line signals, ensuring transparent audio fidelity across the signal chain without coloration. Input impedance specs range from >50 kΩ balanced to >25 kΩ unbalanced, accommodating both professional and consumer-level source devices without compromise, so you can confidently integrate existing venue gear into your signal flow.

Control & Metering Systems

On-unit control includes hardware-managed microphone gain adjustment per channel, 4 independent six-segment lightpipe output meters (-30 to +20 dBu) for quick visual feedback during setup and operation, and an LCD display providing real-time information on source selection, page navigation, zone volume, and mute status. Ethernet and RS-232 ports enable remote operation and integration with third-party control systems, while 2 input insert positions and 1 output insert position allow external processing to be patched directly into the signal flow for custom sonic shaping or system-wide dynamics control.

Key Features

• 19-inch rackmountable chassis (19 × 7.75 × 1.75 inches)
• 6 total inputs: 4 balanced mic/line switchable via Euroblock, 2 unbalanced RCA pairs
• 4 independent outputs with zone-based routing
• dbx Type IV A/D converter with >113 dB dynamic range (line)
• Maximum input levels: +20 dBu Mic/Line (Euroblock), +12 dBu RCA
• Output impedance: 120Ω balanced, 60Ω unbalanced
• 4 independent six-segment lightpipe output meters (-30 to +20 dBu)
• Hardware-controlled microphone gain per channel
• 2 input insert positions and 1 output insert position for external processing
• AutoWarmth psychoacoustic function on each output zone
• Ethernet and RS-232 control ports for third-party system integration
• 100–240 VAC input, 29-watt power consumption; weighs 6.05 lbs

The 640m delivers independent zone control with transparent audio quality and flexible I/O architecture, making it a dependable choice for touring sound rigs and fixed installations requiring reliable digital processing and expandable system control.