Ceiling mounted, two-way vented enclosure

The C4.8T is an extremely compact, two-way flush mount loudspeaker designed to deliver high performance and high intelligibility in a wide range of applications. The unit consists of a 4" (100mm) bass driver with a UL rated, carbon fibre loaded polypropylene cone and a 0.8" (19mm) dome tweeter mounted side by side on the baffle. This configuration easily outperforms coaxial stalk-mounted tweeter or single driver arrangements in terms of wide dispersion and smooth off-axis frequency response. The exceptionally wide dispersion of the C4.8T makes it particularly suitable for installation in low ceilings where significantly fewer units will be required to cover a particular area.

These products comply with UL2043 Fire Tests for Heat & Visible Smoke Release for Discrete Products and their Accessories Installed in Air Handling Spaces.

Listed UL1480 General Signalling Speakers.




  • Two-way high performance flush mounting ceiling speaker
  • 4" (100mm) UL94V-0 carbon fibre loaded polypropylene cone bass driver
  • Very wide dispersion – 180° up to 10kHz
  • High & low impedance operation – transformer included
  • Fireproofed rising clamp plug and socket for easy pre-wiring
  • 100dB continuous max SPL @ 1 metre
  • Steel backcan
  • Tile rails and C bracket included
  • UL2043 & UL1480


  • Fixed installations in ceiling and walls
  • Low ceiling environments


Technical Specification – View
TYPE Ceiling mounted, two-way vented enclosure
FREQUENCY RESPONSE (1) 100Hz-20kHz ± 3dB
-10dB @ 80Hz
DRIVERS 4" (100mm) UL94V-0 PP bass driver
0.8" (19mm) dome tweeter
RATED POWER (2) 40W AES, 160W peak
MAXIMUM SPL (4) 100dB continuous, 106dB peak
DISPERSION (-6dB) 180° conical up to 10kHz
CROSSOVER 5kHz passive
ENCLOSURE Steel backcan
FINISH Bezel & grille – white UV resistant
Backcan – zinc plated
PROTECTIVE GRILLE Perforated steel
CONNECTORS Rising clamp plug and socket
ACCESSORIES (included) 25W 70/100V line transformer
Tile rails
C bracket
Paint mask
Cut-out template

100V – 25W, 12.5W, 6W
70V – 25W, 12.5W, 6W, 3W

DIMENSIONS (OD) 205mm x (D) 131mm
(OD) 8.1ins x (D) 5.1ins
CUT-OUT DIAMETER 178mm (7.01 ins)
WEIGHT 2.6kg (5.7lbs)
Technical Drawing – View
Architectural Specifications – View


Architectural Specifications

The loudspeaker shall be a wide-dispersion, two-way, in-ceiling system consisting of a 4” low frequency transducer and a 0.8” 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 removable, perforated steel grille.

Input connection shall be made via a four-pin rising-clamp plug and socket with loop-through capability to enable pre-wiring with up to 2.5mm2 cable prior to installation. The connector shall be protected from fire by a steel cover with a clamped cable entry. An attachment tag on the backcan shall enable direct attachment to the building structure as a secondary support.

The loudspeaker shall include a steel support ring and tile rails.

Dispersion shall be 180° conical up to 10kHz. The on-axis frequency response shall be 100Hz-20kHz +/- 3dB and the loudspeaker shall produce a maximum SPL of 106dB peak calculated at 1 metre. Power handling shall be 40W AES, 160W 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.

Dimensions (OD x D) shall be 205mm x 131mm (8.1ins x 5.1ins). Weight shall be 2.6kg (5.7lbs).

The loudspeaker shall be the Martin Audio C4.8T.

Commercial Installation

Further Information


Recommended Amp

MA 2.8Q