Cambridge Sound Qt® E-P-B-25-4 Active emitters for sound masking, paging & music (Black) 4 Pack - 911.0897.900

Product Overview

The Cambridge Sound Qt E-P-B-25-4 (part number 911.0897.900) is a four-pack of Qt Active Emitters in black with 25-foot patch cables for QtPro direct-field sound masking systems. Each emitter combines sound masking with clear, simultaneous reproduction of paging and background music from a single ceiling-mounted source. Active electronics and a ported enclosure extend output 17 dB louder and lower in frequency than previous direct-field emitters. The emitters are UL 2043 plenum rated and nearly invisible once installed in finished or open-structure ceilings.

Product Description

Emitters are the ceiling loudspeakers of a sound masking system, and the Qt Active Emitter distributes masking directly into the workspace instead of bouncing it off the ceiling deck the way conventional in-plenum loudspeakers do. This direct-field approach produces a more uniform masking level and clearer paging, since pages and music face the listener rather than passing through ceiling material. The ported enclosure extends sound masking response down to the 125 Hz octave band and paging/music response down to 115 Hz, with a maximum paging/music output of 74 dBA at 1 meter. Four auto-sequencing uncorrelated audio channels reduce phasing and comb-filtering between adjacent emitters. Each unit connects over standard RJ-45 category UTP cabling, draws a maximum of 2 watts at 36 VDC, and includes an acoustic ceiling tile mounting ring with a slip-ring mount. Rear DIP switches trim output in 1.5 dB steps down to -4.5 dB for fine balancing. The emitters work with Qt 300 and Qt 600 control modules and are compatible with the DynasoundPro network system (specify DS1320). Pair them with control modules and cabling from the Cambridge Sound collection.

Key Features

• Masking, Paging, and Music in One Emitter — a single ceiling speaker covers all three functions for office environments.
• Direct-Field Quiet Technology — distributes masking evenly into the workspace without relying on plenum reflections.
• Active Electronics — integral amplifier delivers 17 dB more output than previous direct-field emitters.
• Extended Low-Frequency Response — ported enclosure reaches the 125 Hz octave band for masking and 115 Hz for paging and music.
• Four Uncorrelated Channels — auto-sequencing channel assignment reduces phasing and comb-filtering.
• UL 2043 Plenum Rated — UL-listed for installation in air handling spaces.
• Adjustable Attenuation — rear DIP switches reduce volume in 1.5 dB increments to -4.5 dB.
• Simple RJ-45 Cabling — connects over 8-conductor category UTP; 25 ft patch cables included for each emitter.
• Tile Mounting Ring Included — slip-ring mount installs in acoustical ceiling tile.
• Qt and DynasoundPro Compatible — works with Qt 300 and Qt 600 control modules; DynasoundPro network systems specify DS1320.

Typical Applications

• Open offices — uniform direct-field masking with integrated paging across open floor plates.
• Call centers — reduces speech distraction between adjacent agent positions.
• Healthcare facilities — supports speech privacy in exam rooms, waiting areas, and corridors.
• Law and financial offices — protects confidential client conversations.
• Conference rooms — masks speech transfer to and from adjacent spaces.

Technical Specifications

Specifications sourced from Cambridge Sound vendor data. Unlisted values are omitted rather than estimated.

FAQ

What makes an active emitter different from a standard Qt emitter?
Active emitters have built-in electronics and an integral amplifier, which adds support for simultaneous paging and background music alongside masking and delivers 17 dB more output than previous direct-field emitters.

Which control modules drive the E-P-B-25-4?
It is compatible with the Cambridge Sound Qt 300 and Qt 600 control modules, and with the DynasoundPro network system (specify DS1320 for that platform).

Can these be installed in a return-air plenum?
Yes. The emitters are UL-listed and comply with UL 2043 for air handling spaces, and ship with a slip-ring mount and ceiling tile mounting ring.

How do I balance levels between emitters?
Rear DIP switches attenuate each emitter in 1.5 dB increments down to -4.5 dB, in addition to system-level control from the Qt control module.