At the centre of it all
The centre-channel speaker is arguably the most important in home theatre – and the HTM81 D4 has an enviable array of advanced technologies to reinforce that point, including Solid Body tweeter-on-top, a decoupled Continuum™ Cone midrange drive unit and twin 200mm (8in) Aerofoil™ bass cones.

Aerofoil bass cone
Our Aerofoil bass cone technology remains an outstanding solution to the conundrum of combining low mass and high stiffness in bass cones, thanks to its carbon-fibre skin and variable-profile foam core. Now, we have added the foam Anti-Resonance Plug for lower distortion and even cleaner bass.

Diamond dome tweeter
One of our most significant accomplishments over the past two decades, the ultra-stiff, supremely accurate Diamond dome tweeter is the perfect combination of low mass, exceptional stiffness and outstanding accuracy. 15 years after we introduced it, we haven’t found a better tweeter dome technology.

Aluminium bass pods
HTM81 D4 mounts two Aerofoil bass cones in twin solid aluminium bass pods, each of which is clamped into an aluminium plate fixed to the stiffest part of its curved cabinet. Formed as single pieces of metal, these stiff structures provide the perfect mechanical location for those powerful bass cones.

The science of sound
Innovation is at the heart of everything we do. We question, we examine, we understand and then we evolve. We use computer modelling to explore and reimagine every aspect of loudspeaker design. Learn more about all the technologies that combine to make 800 Series Diamond™ so special here.