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-fiber 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.
Aluminum bass pods
HTM81 D4 mounts two Aerofoil bass cones in twin solid aluminum bass pods, each of which is clamped into an aluminum 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.
Size & weight
Dimensions Height: 334mm (13.1 in)
Width: 847mm (33.3 in)
Depth: 371mm (14.6 in)
Net weight 32.20kg (71 lb)
Technical features Diamond tweeter
Solid body Tweeter-on-Top
Continuum™ cone FST
Aerofoil™ cone bass units
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
Cabinet finishes Gloss Black
Grille finishes Black