Epos ES25 Loudspeaker

MS10 Loudspeaker

Classic 50 Loudspeaker

Epos ES22 Loudspeaker

MS30 Loudspeaker

Epos Cabinet & Rear Baffle Detail

MS CS-1 Loudspeaker

Epos Cabinet & Front Baffle Detail

After graduating from the University of Southampton, I joined Mordaunt-Short and Epos Acoustics in 1992 as a Loudspeaker Design Engineer. Mordaunt-Short was bought by TGI PLC in 1987 which already owned Tannoy and Goodmans Loudspeakers Limited (GLL), forming the largest loudspeaker manufacturing company in Europe.

I learnt the practical skills of loudspeaker design from Robin Marshall who had founded Epos Acoustics in 1983. Robin sold Epos Acoustics to TGI and became the Technical Director for Mordaunt-Short and Epos Acoustics.

As part of a small engineering team, I developed the drive units and systems for the Music Series, Classic Series and Home Theatre ranges of Mordaunt-Short loudspeakers as well as the Epos ES22 and ES25 loudspeakers. All of the loudspeaker systems and drive units were designed and hand-built in-house at the Havant headquarters shared with GLL.

Transducer Design

The 25mm tweeter domes were formed from aluminium alloy and used a polyamide suspension. The dome was acoustically loaded by a separate rear chamber, and vents in the coil former equalised the pressure on the voice coil to eliminate asymmetric pressure distortion.

The bass and midrange transducers used injection moulded or vacuum formed polymer cones, nitrile rubber roll surrounds and central phase plugs with the design goal of providing a well behaved roll-off characteristic. The voice coils were wet-wound on an aluminium formers with high-temperature wire. The wet-wound resin adhesive was used in preference to the more common solvent bonding to provide higher power handling and reliability.

Enclosure Design

All the cabinet enclosures were manufactured in the UK from balance veneered MDF. The cabinet panel thicknesses varied to disperse the resonance frequencies and extensive internal bracing was used to increase the rigidity of the enclosures and minimise panel vibration.

Crossover Design

The fundamental design principle was that the best sounding crossover is NO crossover. In fact, the midrange drivers of the Epos products were directly coupled to the power amplifier for transparency and detail. All other filter networks were first-order electrical alignments. All Epos loudspeaker internal connections were hard-wired rather than the more common and less expensive method of mounting components on a PCB.