BM mk V 12″ Subwoofer


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SKU: BMmkIV12 Category:


We pulled out all the stops and have designed and tooled all critical components from the ground up. The BM mkV has 14mm of one-way linear travel via XBL^2 motor , a new custom-tooled S surround, 3 inch diameter copper voice coil, two-piece flat carbon fiber diaphragm, an aluminum shorting ring in the middle of the two magnetic gaps, and a 12 ring neodymium cluster magnet structure. We have shoved all of that technology into an incredibly compact package of only 3.4” deep. It also requires only 0.5 cubic feet of sealed enclosure space to achieve optimum performance.

Additional information

Weight 12.2 lbs
Dimensions 14 x 14 x 7 in
  • 12″ subwoofer
  • 3.4″ mounting depth
  • 14 mm Xmax
  • 3″ diameter, 8 layer copper voice coil
  • Dual 2 Ohm
  • 500 watts power handling
  • Flat carbon fiber diaphragm
  • Custom tooling of virtually every part
  • 12 ring neodymium magnet cluster

BMmkV Specifications Drawing

Enclosure Information:

  • Sealed = 0.5 – 0.7 ft^3
  • Mounting depth: 86.3 mm (3.39 inches)
  • Cutout diameter: 285 mm (11.2 inches)
  • Overall diameter: 320 mm (12.59 inches)
SI BM mkIV Dual 2 ohm voice coils
Re 4.1 ohms
Fs 28.5 Hz
Qes 0.55
Qms 6.7
Qts 0.51
Le 3.4 mH
Sd 55864 mm^2
Vas 33.3 L
Bl 23.4
Mms 412.3 g
Cms 75.1 um/N
Sensitivity (2.83V/1m) 86.4 db
Xmax 14.0 mm

What is the mounting depth if mounted on a normal 3/4″ piece of material?

When mounted to a 3/4″ piece of MDF, or other material, the internal mounting depth of the BM mkIII is 2.65″ (67.31 mm).


What size enclosure can I put the BMmkV in?

For optimum performance the enclosure volume can anywhere between 0.5 ft^3 and 0.7 ft^3 sealed.


How much room does the BMmkV take up inside the enclosure?

The BM mkV 12” subwoofer displaces 0.05 ft^3.


How much room do I need behind the subwoofer?

If you have no other choice, you can put the back of the BMmkV 1/8” away from the back of your enclosure. Ideally there should be 0.25” to 0.5” of space behind the BMmkV.


Does the BMmkV need 500 watts to perform?

The new BMmkV is a very efficient subwoofer thanks in part to its XBL^2 enabled motor and it does not need every bit of its power handling limit in order to perform well.  In its recommended enclosure volume of 0.5^3 sealed, the BMmkV’s ideal power range is 200 to 400 watts.


What is the frequency response?

Typical in-car frequency response is 16 Hz to 500 Hz.


How much does it weigh?

The weight of a single BMmkIV is 12.2 lbs.