CSP-428 Commercial Sound Processor

CSP-428 Commercial Sound Processor

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The DSP for quick-turn installations — Bose Professional commercial sound processors are part of a comprehensive platform that includes loudspeakers, controls, and software that help installers deliver premium sound systems efficiently. An onboard CSP configuration utility and intuitive browser-based UI provide a quick-setup workflow. Common tasks are presented in a logical manner, so you can configure the system faster, reducing installation time while increasing setup accuracy. Once installed, proprietary algorithms offer predictable performance while optional interfaces — such as ControlCenter digital zone controllers and the ControlSpace Remote app — make operation easy for end users.


Right-sized connectivity for cost-effective commercial installation — 2 x 2 balanced analog I/O, 2 pair mono-summed RCA inputs, 8 control inputs, 1 control output, mute contact, Ethernet port, and Bose Professional AmpLink connectivity

CSP configuration utility with browser-based UI facilitates real-time display and control of levels, routing, thresholds, priorities, scheduled events, Bose Professional loudspeaker EQs, plus input and area EQs

Rear-panel Ethernet port for PC/Mac configuration; also allows for connection to networks supporting ControlCenter digital zone controllers and the ControlSpace Remote app

AutoVolume compensation continuously adapts zone output level based on ambient noise when paired with the Bose Professional AVM-1 sense microphone (sold separately)

Opti-voice paging provides a smooth transition between music and announcements

Opti-source level management monitors input level of up to 4 sources, maintaining consistent volume when switching sources

SmartBass processing expands performance and response at any listening level

AmpLink output for simplified digital audio connection to compatible power amplifiers, reducing terminations, and related points of failure

Intuitive end-user operation — optional ControlCenter CC-1D, CC-2D, and CC-3D digital zone controllers and ControlSpace Remote app provide easy volume control and source selection


  • Retail stores
  • Restaurants
  • Hospitality venues


Technical Summary

Signal Processor/CPU
32-bit fixed/floating-point DSP + ARM, 456 MHz

Input Channels
2 analog (balanced, Mic/Line Level/Page-In)
2 analog (unbalanced, RCA Line-in, summed to mono)

Dynamic Range
115 dB, A-weighted 20 Hz to 20 kHz, analog through, 600 Ω load

Output Channels
2 analog (balanced, Line Level)
8 digital (AmpLink output)


Mechanical Diagrams

Bottom View

Back View

Side View

Top View

Front View

ISO View


ControlCenter digital zone controllers
ControlCenter digital zone controllers
AVM-1 Sense Microphone
AVM-1 Sense Microphone