Fostex BK-20 Cabinet - Sold Flat - Each

Fostex BK-20 Cabinet - Sold Flat - Each
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Price: $235.00


  • Buy 10 - 10,000 and get an additional 10 % off
Manufacturer: Fostex
Product ID : bk20
Weight: 67.00 lbs
Manufacturer: Fostex
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Folded Horn BK-20 Baltic Birch Cabinet - Pre-cut Wood for 8" Full Range Speaker

(Loudspeaker not included) (Here is a link to the kit with loudspeakers)

The wood pieces for the BK20 are all pre-cut and sold flat. The side walls have been grooved to make positioning and assembly easier. The Baltic Birch is 11/16" thick and doubled up for the front baffle per the Fostex cabinet plans.

The driver hole has been cut to 182mm (7.16") to accept most Fostex 8" full range speakers. The rear of the driver hole has been well chamfered to allow for optimal air flow. Feel free to try other 8" full range drivers in this cabinet. The maximum depth of driver this cabinet will accept depends on the magnet structure. The wall opposite the driver through hole is angled. It measures 127mm (5") from front baffle to back wall on the bottom of the hole, and 150mm (5.93") from front baffle to back wall on the top of the hole. You can always carve out some of the back wall or fabricate a spacer should your driver not quite fit. 

We recommend the Fostex FE206En full range speaker (shown in photo), but the cabinet will also work for the FE208E Sigma.

Please look at the BK-16 and BK-12m kits as an example of what this will look like finished.

You may also decide to add a super tweeter to your speaker. The Fostex T90A would be a good choice, it works very well in the BK-16 kit.

The rear panel is pre-cut for a perfect flush mount of the TD-CUP dual binding post input cup. This allows for the easy addition of a super tweeter.  Don't forget to order these with your cabinets from the drop down menu.

Assembly instructions are included. Wood glue and clamps are recommended for assembly.

After assembly, you may wish to round off the corners, stain, clear coat, or paint the cabinet.

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Product Reviews

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Reviewed by janerikrasmussen
11/26/2013 - 12:54:52 PM
Great Sound!

After some emailing with Madisound and Adam i desided on the BK20`s without the tweeters (T90A).
The building was quite easy (i am a first timer) but Madisound could have made a manual that shows gluing, stuffing and each step with better pictures (real photos) that would have made it even better.

But...the sound is amazing so far, i have no stuffing behind the driver yet (Fostex 206En) i tried with the recomended first, but the bass was "boomy or hollow) but i will experiment with this. I stuffed the back, top and sides, splitting the amount in half.

Any tips here Madisound?

If Madosund can give me some hints for placement, i am listening quite close 2,5 meters, and tow inn, it would be great.

When i listen to vocal jazz (Diana Krall) i can hear everything thats going on in the background (Live In Paris) i hear things in her mount when she sings, i hear when she presses the pedals on the piano etc, the details are great.

I was not expecting much as for the low tones and the bass, but i think it sounds good with enough bass for the music i like...jazz, blues, soul, pop and some classical.

I live in Norway, so my shipping cost and taxes was quite high, but i do not regret.

I am recomending these to anyone who wanna try backloaded horns, i have never heard or tried it, but i am very happy that i took the chance.
Great service from the guys at Madisound!

Best Regards
Jan-Erik Rasmussen, Norway