Subwoofers

The sub has a bass level control that can also be fixed for THX processors and receivers, a variable phase control (0-180), and a choice of low pass filter options (variable, 80Hz fixed, and no filter at all). There's also a THX Bass EQ setting for full bass extension, and an Anechoic MK EQ setting for smaller rooms or music reproduction. Naturally, I picked the former.

Off To A Flyer
Testing kicked off with my usual one-two of Edge of Tomorrow and House of Flying Daggers, Blu-rays that have sequences ideal for evaluating the capabilities of a sub.

The X15+ handled the deep bass note at the start of the former with admirable skill, suggesting M&K's claim that it can go well below 20Hz is accurate. This is bass you feel rather than hear, with frequencies so low they're actually scary.

Despite visual appearances to the contrary, the X15+'s cabinet is acoustically sealed, with the large open space at the bottom venting the sub's increased output into the room, rather than tuning it. The 'Drum Dance' sequence in House… is a test of speed, control and agility, and the X15+ proved surprisingly nimble for something so, so big.

Since this woofer is certified THX Dominus, I reached for the 4K disc of Jurassic World. When we're first introduced to the film's hybrid dinosaur villain – the appropriately named Indominus Rex – we hear rather than see it. The X15+ did a superlative job of adding scale and making you think there's a 50-foot creature lurking in your room.

There was an undeniable authority to this subwoofer's performance, such as when the giant Mosasaurus slams into the water as our young heroes get their first taste of the park's star attractions. But later, when the Indominus Rex attacks them in a bubble tour vehicle, the X15+ also impressed with its ability to articulate fine bass details, evoking the beast's heavy breathing and stomping feet.

When you want to feel bass hit you like a tsunami, Godzilla vs Kong (4K BD) is an obvious choice. The first punch-up between the two titans takes place at sea, and when Kong jumps onto the deck of an aircraft carrier, the X15+'s dual drivers hit like a sledgehammer. The impact was improbably deep, but controlled and powerful too.

Skip to the climactic Hong Kong scrap between Godzilla, Kong and Mechagodzilla, and the sense of slam and scale this subwoofer brought to the skyscraper-destroying action was gobsmacking to the point I worried about the integrity of my own house. Yet at no point did the X15+ ever feel overwhelmed by the massive LF requirements put on it. It just seemed to breeze through.

Got Anything Smaller?
M&K has achieved the near-impossible task of delivering subterranean depth with remarkable speed and agility – like an acoustic combination of bricklayer's shoulders and ballet dancer's feet. The X15+ is probably too big for most UK installations, but I imagine the smaller and more affordable X12+ and X10+ models would be more than up to the job.

Ultimately this sub offers the kind of performance we expect from a manufacturer that has been a pioneer of the idea of subwoofers in the home. But, considering the sheer size of the X15+, it's more likely to be a stately home n

HCC Verdict

M&K Sound X15+

Price: £5,995
mksound.com

We say: This behemoth uses its push-pull driver configuration to generate seismic amounts of bass, while managing to be remarkably detailed and articulate in the process. Stunning.

Overall: 5/5

Specifications

DRIVE UNITS: 2 x 15in extra long-throw drivers ENCLOSURE: Sealed cabinet with push-pull driver configuration ONBOARD POWER (CLAIMED): 700W (RMS) ICEpower Class D amp FREQUENCY RESPONSE (CLAIMED): 16Hz-200Hz (+/-3dB) REMOTE CONTROL: No DIMENSIONS: 833(h) x 515(w) x 460(d)mm WEIGHT: 61kg

FEATURES: Stereo/LFE line-level RCA and balanced XLR inputs; line-level RCA and balanced XLR passthrough outputs; bass level control (THX fixed or variable); switchable low pass filters (fixed 80Hz, variable, THX no low pass); continuously variable phase control (0-180 degrees); switchable LFE (optional THX or MK EQ modes); auto on feature