18 Sound ND3SA – Larger-Chassis Aluminium-PEN Sibling with Stronger 2.1T Ring Magnet
The 18 Sound ND3SA 1.4-inch exit neodymium high-frequency compression driver has been designed for high-level sound systems applications. The unit has been developed to fulfil tight geometrical requirements, thanks to its compact overall diameter — sharing the ND3A’s fundamental aluminium-PEN diaphragm philosophy, next-gen 4-slot phase plug, and self-centering d-kit, but built on a genuinely larger 120 mm chassis with a stronger 2.1 T ring magnet.
The diaphragm assembly is composed of an aluminium dome sandwiched to a proprietary treated PEN suspension. This design maintains low resonance and, when compared to the titanium version, lowers the minimum crossover point value to 1000 Hz. The composite diaphragm assembly is made by an aluminium dome strongly joined to the PEN suspension, in order to assure unmatched transient response. The lower density of the aluminium and PEN structure permits higher levels of sensitivity, especially in the mid-high frequency range.
Design and Construction of the 18 Sound ND3SA
A bended former edge-wound aluminium 75 mm voice coil completes the diaphragm assembly. In comparison with a usual straight former joint, the ND3SA moving assembly design assures extended frequency energy transfer for improved response linearity and unparalleled reliability, facilitating proper motion control of the dome in real working conditions. The proprietary treated Nomex former carries the same 30% higher tensile elongation figure versus Kapton documented consistently across 18 Sound’s HF range.
The diaphragm kit self-centering design allows high-precision mounting and at the same time makes the servicing procedure very easy. Despite its compact size, the neodymium magnet assembly has been designed to obtain a stronger flux density — 2.1 T, exceeding the ND3A’s 2.0 T — for major benefits in transient response.
The motor structure, through the precisely coherent metal alloy phase plug with 4 circumferential slots and copper ring on the pole piece, reduces inductance effect and distortion. A special treatment applied to the magnet and the top and back plates makes the driver more resistant to the corrosive effects of salts and oxidisation — more effective than any other coating commonly used.
At 2.3 kg, 120 mm overall diameter, and 53 mm depth, the 18 Sound ND3SA is genuinely larger and heavier than the ND3A (1.65 kg, 109 mm) despite sharing the same fundamental diaphragm and phase plug technology — the stronger magnet structure accounts for this scale difference.
Performance and Applications for the 18 Sound ND3SA
The 18 Sound ND3SA delivers 112 dB sensitivity across a 0.8 – 20 kHz frequency range, with a recommended crossover of 1.2 kHz using a 12 dB/octave or steeper high-pass filter — matching the ND3A’s sensitivity and crossover recommendation exactly, from the larger, stronger-magnet chassis.
The published continuous power handling of 220 W matches the ND3A, though the feature bullet list separately states 240 W maximum program power handling — a specific discrepancy worth confirming directly against the datasheet PDF before final specification, consistent with similar marketing-text-versus-spec-table inconsistencies documented elsewhere in this session.
For applications where the stronger 2.1 T magnet’s transient response benefits are valued, and where the marginally larger chassis footprint is acceptable, the 18 Sound ND3SA delivers a genuine alternative to the more compact ND3A within 18 Sound’s aluminium-PEN 1.4-inch range.
Conclusion – 18 Sound ND3SA Compression Driver
The 18 Sound ND3SA is a larger-chassis, stronger-magnet sibling of the ND3A, sharing the same aluminium-PEN diaphragm and next-gen 4-slot phase plug technology at a genuinely larger 120 mm overall diameter and 2.3 kg weight. Note the page’s own internal inconsistencies around overall diameter (109 vs 120 mm) and power handling (220 vs 240 W) — worth confirming against the current datasheet before final specification.
For applications where the ND3A’s compact scale isn’t strictly required, and the stronger ring magnet’s transient response advantage is valued, the 18 Sound ND3SA delivers a genuinely capable alternative within 18 Sound’s 1.4-inch aluminium-PEN range.
VIEW MORE 18 Sound PRODUCTS HERE.
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.
