M&K Sound unveils new X+ Series line of THX Certified reference subwoofers

M&K Sound X+ Series subwoofers
(Image credit: M&K Sound)

M&K Sound has just unveiled a new X+ Series line of THX Certified reference subwoofers. The self-proclaimed 'inventor of the subwoofer' has overhauled the firm's X Series with three new X+ Series models, including the company’s first THX Dominus Certified 15-inch X15+ subwoofer. 

On that claim of having invented the subwoofer, it is up for debate, although one of the earlier commercially available subwoofers was developed by Ken Kreisel in the late 1960s, the former president of the Miller & Kreisel Sound Corporation in Los Angeles. When Kreisel's business partner and high-end audio shop owner, Jonas Miller, told Kreisel that a few electrostatic speaker buyers had complained about a lack of bass response, Kreisel designed a powered woofer that would reproduce only those frequencies that were too low for said speakers to convey. So there we are.

In total, there are three brand new subwoofers: the X15+, X12+ and X10+, all now with THX certification. Each also boasts M&K Sound’s signature push-pull driver configuration, built on the company’s former X Series. All of them have achieved coveted THX status, with the X15+ being the company’s first 15-inch push-pull subwoofer to gain THX Dominus class certification, whether used as a single subwoofer or as a pair. 

As well as introducing the company’s first ever 15-inch subwoofer, M&K Sound’s engineering team has added numerous upgrades to the original X Series to create the X+ range, including big RMS and peak wattage power hikes to enable cleaner performance over the former X10 and X12 models, care of brand-new Danish designed and built ICE Class D power amplifiers. The new X15+ boasts 700W RMS / 1400W Peak; the X12+ promises 600W RMS / 1200W Peak (up from 400W RMS / 700W Peak in the X12)  and the X10+ lists 500W RMS / 1000W Peak (from 450W RMS / 600W Peak in the older X10). 

Also updated and redesigned are the woofers themselves, with new carbon fibre cones plus 30 per cent larger voice coils and magnets (in the X12+ and X10+) to facilitate the substantial power output of the new subwoofers. The range also promises ‘feel it but can’t hear it’ bass frequencies as low as 16Hz (X15+), 18Hz (X12+) and 20Hz (X10+). 

On to those certifications. THX's gold seal of excellence promises the consumer they can expect movie soundtracks “as the director intended” – after all, THX was founded by iconic filmmaker George Lucas in 1983. The (dual 10-inch driver) X10+ has gained THX Certified Select status, the (dual 12-inch driver) X12+ is THX Certified Ultra, and (dual 15-inch driver) X15+ boasts THX Certified Dominus, endorsements which should mean movie and music lovers can enjoy professional cinema audio reference levels in their living rooms of up to 2,000ft³ 3,000ft³ and 6,500ft³ respectively. 

M&K Sound X10+ subwoofer

(Image credit: M&K Sound)

M&K Sound’s push-pull subwoofer architecture and ‘reversed double driver’ non-isobaric configuration means that both drivers in the cabinet are ‘exposed’ to room air. Consequently (and like the X-Series before it) the X+ Series models are effectively two subwoofers in one cabinet, boasting a further associated reduction in distortion. This is made possible by having one inverted driver in relation to the other cancelling non-linearities to produce symmetric waveforms.

The X15+, X12+ and X10+ all feature full 25mm MDF construction and bracing to further minimise panel vibrations or cabinet resonances, and increased venting at the base of the woofers to mitigate distortion due to air turbulence. These milled cavities also act as convenient carrying handles for installation efficiency.

Cosmetic makeovers for the X+ Series arrive in the form of flush-mounted front baffles and convenient invisible magnetic grille attachment mechanisms.

The M&K Sound X+ Series will be available in January 2022 from authorised M&K Sound dealers, priced $4499 / AU$6499 for the X10+, $4999 / AU$7999 for the X12+ and $5999 / AU$8999 for the X15+ (so, starting at approximately £3410 for the smallest X10+, although official pricing is not yet known).


See M&K Sound V10+ shows how low a compact subwoofer can go

Read our pick of the best subwoofers: deep bass for music and movies

Also, Magico's Titan 15 subwoofer promises 6500W of earth-shaking bass

Becky has been a full-time staff writer at What Hi-Fi? since March 2019. Prior to gaining her MA in Journalism in 2018, she freelanced as an arts critic alongside a 20-year career as a professional dancer and aerialist – any love of dance is of course tethered to a love of music. Becky has previously contributed to Stuff, FourFourTwo, This is Cabaret and The Stage. When not writing, she dances, spins in the air, drinks coffee, watches football or surfs in Cornwall with her other half – a football writer whose talent knows no bounds.