* Stand not included.

Our largest centre-channel speaker is designed to partner the 801 D4 and 802 D4. A powerful performer, it has both the scale and the midrange extension to perfectly match the quality of its illustrious stablemates. 

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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 (8-in) Aerofoil™ bass cones.

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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.

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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.

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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.

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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.

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Specifications

Technical features	Diamond tweeter Solid body Tweeter-on-Top Continuum™ cone FST Anti-Resonance plug Biomimetic Suspension Matrix™ Aerofoil™ cone bass units Flowport
Description	3-way vented-box system
Drive units	1x ø25mm (1in) Diamond dome high-frequency 1x ø150mm (6in) Continuum cone FST midrange 2x ø200mm (8in) Aerofoil cone bass units
Frequency range	20Hz to 35kHz
Frequency response	28Hz to 28kHz (+/-3dB from reference axis)
Sensitivity	90dB (on axis at 2.83Vrms at 1m)
Harmonic distortion	2nd and 3rd harmonics (90dB,1m on axis) <1% 80Hz – 20kHz <0.3% 100Hz – 20kHz
Nominal impedance	8Ω (minimum 3.0Ω)
Recommended amplifier power	50W – 500W into 8Ω on unclipped programme
Max recommended cable impedance	0.1Ω
Dimensions	Height: 334mm (13.1 in) Width: 847mm (33.3 in) Depth: 371mm (14.6 in)
Net weight	32.20kg (71 lb)
Cabinet finishes	Gloss Black White
Grille finishes	Black Grey

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