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Adorn SeriesInstalled Sound


Compact Two-Way 5.25" Ceiling Speaker

Where to Buy or Rent

As part of the ADORN commercial series, the ACS-55T is a compact, two-way ceiling speaker designed for background and foreground applications that require premium performance and cost competitiveness.


  • High performance two-way ceiling speaker
  • 5.25” (100mm) LF driver and 0.75” (19mm) HF dome tweeter
  • Wide 150° conical coverage pattern reduces speaker count required for even coverage
  • 70V/100V multitap line transformer or 16 ohm low-impedance operation
  • Low and high-frequency overload protection
  • UL94V-0 rated baffle with zinc-plated steel backcan
  • Quick release, bezel-less grille
  • Tile rails and C-ring included
  • 5-year warranty


  • Retail outlets
  • Cafes, bars and restaurants
  • Museums and Houses of Worship
  • Hotels, casinos and concourses
  • Transportation facilities
  • Boardrooms and reception areas

The ACS-55T brings full-frequency response, consistent coverage and intelligibility to a wide range of architectural environments — from hotels and concourses to retail outlets, bars and restaurants.

Comprising a 5.25” (100mm) LF driver and a 0.75” (19mm) silk-dome tweeter, the CS-55T produces 113dB peak output at 1 metre and has a high-fidelity sonic character ideal for both music and speech reproduction. Its ported bass reflex design and backcan with generous internal volume maximises low frequency output and delivers strong bass that extends down to 62Hz.

The wide 150° conical coverage of the ACS-55T reduces the number of speakers required for even coverage — leading to a reduction in installation cost.

It incorporates a high-quality transformer for 70V/100V line operation, with transformer taps selected by a rotary switch accessible behind the powder-coated, perforated steel grille. The switch also provides for 16-ohm low impedance operation — enabling four or more speakers to be driven in parallel from a single amplifier channel. For full-bandwidth protection, the low and high-frequency sections are individually protected against overload by auto-resetting thermal fuses.

The grille is bezel-less for a clean look, its bayonet fitting is easy to remove without the use of tools and finished in white (RAL9016) to match ADORN on-wall loudspeakers and may also be painted to blend with any décor.

TYPECompact, passive two-way ceiling speaker, ported bass reflex
FREQUENCY RESPONSE (1) 98Hz-20kHz ± 3dB -10dB @ 62Hz
  • LF: 5.25” /1” high-temp voice coil, coated paper cone, rubber surround, ferrite motor, pressed steel chassis
  • HF: 0.75” silk dome, neodymium motor
RATED POWER (2)50W AES, 200W peak
RECOMMENDED AMPLIFIER VIA2004 (for low-impedance operation)
SENSITIVITY(4) 90dB / 1W(4V) / 1m
MAXIMUM SPL (9) 113dB peak
DISPERSION (-6dB)150° conical up to 7kHz
CROSSOVER3kHz passive (LF and HF auto-resetting fuses)
TRANSFORMER TAPS70V: 30w / 15w / 7.5w / 3.75w
100V: 30w / 15w / 7.5w
ENCLOSURE UL 94V-0 rated ABS baffle with steel backcan
FINISH Baffle and grille: RAL9016 white Backcan: zinc plated
GRILLE Perforated steel, powder-coated, bayonet fitting
CONNECTORS Ceramic connector (in and link) located behind fire-retardant steel cover
ACCESSORIES (included)
  • 2 tile rails
  • C-ring backing plate
  • Cut-out template
  • (OD) 245mm x (D) Back Can 192mm, (D) Inc. Grille 209mm
  • (OD) 9.7in x (D) Back Can 7.55in, (D) Inc. Grille 8.23in
WEIGHT 3kg (6.6lbs)
Architectural Specs

The loudspeaker shall be a wide-dispersion, two-way, in-ceiling system consisting of a 5.25” low frequency transducer and a 0.75” dome high frequency transducer mounted in a ported enclosure. The enclosure shall comprise a pressed steel backcan with a UL94V-0 fire-rated moulded baffle. The transducers shall be protected by a quick-release perforated steel grille.

Input and loop through connections shall be made via a ceramic connector located behind a fire-retardant steel cover.

The loudspeaker shall include a steel support ring and tile rails. A safety ring on the backcan shall enable direct attachment to the building structure as a secondary support.

Dispersion shall be 150° conical up to 7kHz. The on-axis frequency response shall be 98Hz-20kHz +/- 3dB and the loudspeaker shall produce a maximum SPL of 113dB peak calculated at 1 metre. Power handling shall be 50W AES, 200W peak.

The loudspeaker shall be equipped with a transformer for 70V or 100V line operation, with taps selected by a rotary switch on the front baffle. The switch shall also provide for 16 ohm low impedance operation of the loudspeaker. Low and high frequency sections shall be integrated by an internal 3kHz passive network, with auto-resetting LF and HF fuses to protect the drivers from overload.

Dimensions including the grille (OD x D) shall be 245mm x 209mm (9.7ins x 8.23ins). Backcan depth shall be 192mm (7.55ins). Weight shall be 3kg (6.6lbs).

The loudspeaker shall be the Martin Audio ACS-55T.

Martin Audio Adorn ACS-55T Tech Drawing

Technical Drawings for Adorn ACS-55T.
All information is Copyright. Martin Audio Ltd.


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Copyright Martin Audio Ltd.
Subject to change without notice.
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