11 September 2011

BK-12m Folded Horn Kit - Fostex FE126En

There is a new high-sensitivity folded horn speaker kit being offered by Madisound.  The new BK-12m is a single-driver folded horn speaker kit that follows in the lineage of the BK-16 and BK-20 designs.  The BK-12m uses the Fostex FE126En full-range speaker driver in a custom folded horn enclosure while the driver is run full range with no filters whatsoever.  The Fostex FE126En driver is 4.7" (120 mm) in diameter with a rated sensitivity of 93dB/W(m).  This high-sensitivity means that the BK-12m speakers will be suitable for use with low powered amplifiers.

BK-12m Folded Horn Kit - Fostex FE126En
The enclosure panels are made using high quality 5/8" (16 mm) thick Baltic Birch multiplex cut using a CNC machine and bundled as a flat pack.  Once completed the speaker cabinets have overall dimensions of 31-5/8" x 7-1/4” x 14-1/2" (800 x 185 x 370 mm).  The Birch plywood is unfinished so you can finish the speakers how you like.

The BK-12m speaker kit includes:
  • 2 x Fostex FE126En 4.5" Full Range Drivers;
  • 2 x Unassembled, unfinished Baltic Birch Cabinets;
  • 3 oz. Acousta-Stuff internal damping material;
  • 5 ft Supra Classic 1.6 15 AWG speaker wire;
  • 4 x QC187 Quick Connects (2 red, 2 black);
  • 8 x 8X1 Socket Head Wood Screws (8x Philips Head wood screws also included);
  • Assembly Instructions.
To put the kit together you will need just a screwdriver, wood glue, sand paper, bar clamps and binding posts.  An inside view of the folded horn speaker enclosure is shown in the photo below.
Inside - BK-12m Horn Speaker Kit - Fostex FE126En
 The BK-12m kit is available from Madisound for $315US + shipping.  For full details about the BK-12m speaker kit see the product page at Madisound.

More single-driver speaker kits and projects:


  1. 4 x QC187 Quick Connects (2 red, 2 black); these will not fit, QC 250 will.

  2. Is wood glue strong enough to hold all the joints together without screws?

    1. Certainly. Wood glues applied correctly make very strong joints.

    2. Certainly. Wood glues applied correctly make very strong joints.

  3. Fostex describes a different design for Horn cabinet in their datasheet. Has someone made a comparison in sound to that.

  4. I usually use screws rather than glue..