1. Stereo Integrity's BM mkIV...

If you want to see where shallow subwoofers are heading in the future, just look at where the SI BM mkIV is today. At only 3.4" of mounting depth, 50 % more linear excursion than the TW5, a miniscule 0.5 ft^3 enclosure requirement, and 450 watts of power handling, the BM mkIV has a big subwoofer attitude in a shallow package.

The all new BM mkIV subwoofer.

It gives other thin subwoofers an inferiority complex.

We pulled out all the stops and have designed, and tooled, all critical components from the ground up. The BM mkIV has 14mm of one-way linear travel, a massive 10” diameter spider, 8 layer copper voice coil, proprietary two piece flat diaphragm, a shorting ring, and a 10 ring neodymium cluster magnet structure. We have shoved all of that technology into an incredibly compact package of only 3.2” deep. It also requires only 0.5 cubic feet of sealed enclosure space to achieve optimum performance.

The BM mkIV is setting a new standard for sound quality subwoofers, both for shallow and regular depth. The BM mkIV has the ability to reproduce deep, articulate bass while at the same time totally disappear giving you the impression that your front speakers possess massive amounts of low-end response. Not being able to pin-point where the subwoofer is located at is exactly what a top notch sound quality subwoofer should do – and that’s exactly what the BM mkIV does.

If you are after the pinnacle of SQ with good output, this is it.




See our FAQ page for frequently asked questions about the BM mkIII and BM mkIV

  Mounting information
~ all dimensions are in millimeters. ~
All mounting specifications are with the supplied gasket:
Mounting depth: 81.3mm
Cutout diameter: 282mm
Overall diameter: 320mm

Gasket information:
Width per side: 26mm
Edge height: 18.5mm
Bottom thickness: 5mm

For a technical drawing of the BM mkIII and BM mkIV Click Here
Click HERE for more technical information.

Click here for Warranty Information

looking for last years models specs.... Click Here

Stereo integrity BM mkIV

  • 12" subwoofer
  • 3.2" mounting depth*
  • 10" diameter nomex spider
  • 14mm Xmax
  • 2.5" diameter, 8 layer copper voice coil
  • Dual 4 Ohm
  • 450 watts power handling
  • Flat aluminum diaphragm
  • Custom tooling of virtually every part
  • 10 ring neo magnet cluster
  • 0.5-0.6 ft^3 sealed enclosure requirement

  • *Without mounting gasket, depth is 3.4"

Ordering Information

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