18 Sound 12W500 – Lightweight High-Sensitivity 12-Inch Ferrite Woofer with 99.5 dB Output and 6000 Hz Bandwidth
The 18 Sound 12W500 is the lightest and highest-sensitivity 12-inch ferrite woofer in 18 Sound’s range. At 99.5 dB — exceeding both the 12W700’s 98 dB and the 12W750’s 97 dB — with a 65 mm ISV coil, 350 W AES power handling, and a 50 Hz – 6000 Hz bandwidth that is the widest of any 18 Sound 12-inch driver we’ve covered, the 18 Sound 12W500 was designed specifically to combine excellent linearity with good sensitivity and power handling from a compact, lighter-weight platform.
The 99.5 dB sensitivity from a 12-inch ferrite woofer is exceptional — 1.5 dB above the 12W700 and 2.5 dB above the 12W750, both of which use larger 75 mm coils. The smaller 65 mm coil and lighter 36.5 g moving mass extract more output per watt than the larger-coil siblings, at the cost of maximum power handling and Xmax.
The 6000 Hz upper bandwidth is dramatically wider than the 12W700’s 4200 Hz and the 12W750’s 4600 Hz — nearly 1800 Hz more upper-frequency extension. 18 Sound designed the 18 Sound 12W500 primarily for compact bass reflex applications in enclosures as small as 50 litres, typically for two-way systems paired with a 1-inch compression driver, and the wide bandwidth supports smooth, high crossover points in exactly that architecture.
At 5.2 kg — 2.3 kg lighter than the 12W700 and 2.3 kg lighter than the 12W750 — the 18 Sound 12W500 is the clear lightweight option in 18 Sound’s 12-inch ferrite lineup. Available in 4 and 8 Ω. 18 Sound lists the 12W700 as the alternative/current model.
Design and Construction of the 18 Sound 12W500
The 18 Sound 12W500 uses a 65 mm (2.5-inch) aluminium ISV (Interleaved Sandwich Voice Coil) wound on a high-strength fibreglass former — noticeably smaller than the 75 mm coils fitted to both the 12W700 and 12W750. The ISV architecture carries windings on both the outer and inner surfaces to achieve the mass-balanced coil that produces an extremely linear motor assembly with reduced eccentric behaviour when driven hard.
The high-quality paper cone has a smooth, curvilinear profile specifically designed to eliminate bell-mode resonances within the intended frequency range — a different approach from the ribbed cone construction on the 12W700, achieving resonance control through profile shape rather than structural ribbing.
The cone is carried by a specially treated, dampened double half-roll linen suspension designed to control excursion while maintaining piston action linearity through the 4.0 mm Xmax — a shorter, more tightly controlled excursion range than either the 12W700’s 6.5 mm or the 12W750’s 8.0 mm, consistent with the driver’s higher-sensitivity, lower-displacement design intent.
The 12.1 Tm force factor driving 36.5 g of moving mass produces 99.5 dB sensitivity — the Bl/Mms ratio of 0.332 Tm/g reflects a motor tuned for efficiency from the lighter coil and cone assembly rather than maximum force. The 0.36 Qts and 121 Hz EBP define a flexible alignment sitting on the sealed/vented boundary.
Voice coil cooling is achieved through airways between the chassis back plate and the top plate of the magnet, channelling heated air from the voice coil and gap away for dissipation through the chassis basket — 18 Sound credits an improved heat dissipation basket design as a specific feature.
At 5.2 kg, 315 mm overall diameter, 282 mm baffle cutout, 141 mm depth, and 16 mm flange, the 18 Sound 12W500 shares the same overall diameter and baffle cutout as the 12W700, but at significantly less weight and slightly less depth.
Performance and Applications for the 18 Sound 12W500
The 18 Sound 12W500 delivers 99.5 dB sensitivity across a 50 Hz – 6000 Hz bandwidth. The 350 W AES / 500 W continuous program power handling is lower than both the 12W700 (450 W AES) and the 12W750 (600 W AES), reflecting the smaller 65 mm coil’s reduced thermal capacity — the direct trade-off for the lighter weight and higher sensitivity.
18 Sound recommends a 75-litre (2.65 ft³) vented enclosure tuned to 50 Hz, with the driver explicitly suited to compact bass reflex enclosures as small as 50 litres. The primary application 18 Sound identifies is compact two-way systems paired with a 1-inch compression driver — the 6000 Hz upper bandwidth supports a high crossover point with substantial overlap, producing smoother filter transitions than the narrower-bandwidth 700-series drivers allow.
The 50 Hz lower frequency limit and 46 Hz Fs confirm genuine bass extension despite the driver’s smaller coil and lighter construction — the 18 Sound 12W500 reaches as deep as the larger-coil 700-series options while weighing considerably less.
The 4, 8 Ω dual impedance availability (compared to the 12W700’s 8 Ω only) provides more system design flexibility for single-driver and multi-driver applications alike.
The comparison across 18 Sound’s 12-inch ferrite range now gives builders three distinct options. The 18 Sound 12W500 delivers the highest sensitivity (99.5 dB), widest bandwidth (6000 Hz), and lightest weight (5.2 kg) — the efficiency and compactness specialist for two-way reflex systems. The 12W700 delivers a middle ground with 98 dB sensitivity and more flexible Qts (0.36) from a heavier ribbed-cone platform. The 12W750 delivers the highest power handling (600 W AES) and most Xmax (8.0 mm) — the displacement and power specialist suited to subwoofer duty as well as two-way use.
Conclusion – 18 Sound 12W500 Woofer
The 18 Sound 12W500 is the lightest, highest-sensitivity, widest-bandwidth 12-inch ferrite woofer in 18 Sound’s range. The 99.5 dB sensitivity and 6000 Hz bandwidth from a 65 mm ISV coil make it the natural choice for compact two-way reflex systems paired with a 1-inch compression driver — exactly the application 18 Sound designed it for.
The trade-offs are honest: 350 W AES is the lowest power handling of the three 12-inch ferrite options, and 4.0 mm Xmax is the shortest. For applications prioritising maximum sensitivity, bandwidth, and minimum weight over raw power handling and displacement, the 18 Sound 12W500 remains a compelling specification even with 18 Sound now pointing to the 12W700 as its listed alternative.
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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.
