18 Sound HD1040 – Treated Polyethylene 1-Inch Compression Driver with Superior Elasticity Modulus
The 18 Sound HD1040 one-inch exit high-frequency compression driver has been designed for use in high-quality audio systems. Unlike the titanium diaphragms documented on the HD1000 and HD1030, the HD1040 diaphragm assembly is made by proprietary treated polyethylene material — a genuinely distinct diaphragm material choice within 18 Sound’s 1-inch range.
Thanks to its superior diaphragm dimensional stability (160°C), the polyethylene shows constant behaviour during its whole working life. Moreover, this particular material, with its very high value of elasticity modulus — 50% more than standard Mylar and 100% more than polyimide film — is capable of superior transient and intermodulation distortion response. This is a genuinely specific, quantified comparison against two named alternative diaphragm materials (Mylar and polyimide), a level of competitive material specificity not documented on any other driver across this session’s HF coverage.
The flat suspension shape is designed to maintain low stiffness and low mid-band distortion and response — a deliberately different suspension geometry from the ellipsoidal shape documented on the HD1030, reflecting the polyethylene diaphragm’s own distinct mechanical requirements.
Design and Construction of the 18 Sound HD1040
Equipped with proprietary Phase Plug architecture, the 18 Sound HD1040 has been designed to give high-level manufacturing consistency and a smooth coherent wavefront at the horn entrance across the whole working frequency range. The phase plug, with its short openings and high flare rate value, assures low distortion and demonstrates remarkable improvements in mid-high frequency reproduction.
An edge-wound aluminium voice coil, wound on proprietary treated Nomex, completes the diaphragm assembly. Thanks to its physical properties, the proprietary treated Nomex former shows a 30% higher value of tensile elongation at a working operative temperature (200°C) when compared to Kapton. This feature enables proper energy transfer control from the voice coil to the dome in real working conditions, and this proprietary former material is suitable for use in damp and wet environments.
The HD1040 powerful ceramic magnet assembly has been designed to obtain 16 kGauss in the gap within a compact ferrite motor structure — 1 kGauss above the HD1000/HD1030’s shared 15 kGauss figure.
At 1.6 kg, 110 mm overall diameter, and 60 mm depth, the 18 Sound HD1040 is genuinely larger than both the HD1000 (1.4 kg, 100 mm) and HD1030 (1.0 kg, 91 mm), reflecting this driver’s stronger magnetic circuit and distinct diaphragm construction.
Performance and Applications for the 18 Sound HD1040
The 18 Sound HD1040 delivers 107 dB sensitivity across a 1.6 – 20 kHz frequency range, with a recommended crossover of 1.6 kHz using a 12 dB/octave or steeper high-pass filter — matching the HD1000’s crossover recommendation exactly, with 1 dB below its 108 dB… actually 2 dB below the HD1000’s 109 dB sensitivity.
The 40 W AES / 80 W continuous power handling sits between the HD1000’s 100 W and HD1030’s 60 W, positioning this driver as a genuine middle option within 18 Sound’s 1-inch range on power handling terms. Available in both 8 and 16 Ω, the 18 Sound HD1040 provides system design flexibility not documented on the 8 Ω-only HD1000 and HD1030.
For applications where treated polyethylene’s specific elasticity and dimensional stability advantages over Mylar and polyimide alternatives are valued, the 18 Sound HD1040 delivers a genuinely distinct diaphragm material option within 18 Sound’s 1-inch compression driver family.
Conclusion – 18 Sound HD1040 Compression Driver
The 18 Sound HD1040 brings treated polyethylene diaphragm technology to 18 Sound’s 1-inch compression driver range — a material choice 18 Sound specifically quantifies as offering 50% more elasticity modulus than Mylar and 100% more than polyimide film, combined with superior dimensional stability at 160°C. Available in both 8 and 16 Ω, this driver occupies the middle power-handling tier within 18 Sound’s 1-inch family, between the entry-level HD1030 and the titanium-PEN HD1000.
For applications specifically valuing polyethylene’s quantified material advantages and 16 Ω impedance flexibility, the 18 Sound HD1040 delivers a genuinely distinct option within 18 Sound’s smallest-throat compression driver range.
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About 18 Sound
18 Sound products are proudly made in Reggio Emilia, Italy, combining advanced technology with Italian craftsmanship. Known for their high-performance professional audio components, 18 Sound is a trusted name in the global audio industry. Their state-of-the-art manufacturing and strict quality control ensure exceptional reliability and sound clarity. 18 Sound products are designed to meet the demands of speaker builders and audio professionals, 18 Sound offers premium products with outstanding value and performance worldwide.
