BK108 mit FE108E Sigma   Floorstanding as in Hobby Hifi 3/2016

Technical data
  • impedance: 8 Ohm
  • sensivity (2,83V/1m): 90 dB
  • size (HxWxD): 915 x 230 x 450 mm
  • frequency range (-8dB): 50 - 20000 Hz
  • crossover frequency(s): Hz
  • speaker type: de bocina

BK108 is a backloaded horn. It is a design of Fostex, Japan.

To flatten the frequency response of the speaker Günter Damde (Saarbrücken, Germany, +49-681-499329) added a crossover.

The fullrange speaker Fostex FE108 E Sigma is used in the floorstander.

The crossover contains two wave traps in series to the speaker.

Our kit consists of

  • Fostex FE 108 EZ (Sigma), 4 inch, full range, 8 Ohm
  • Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • Foam N25-30, 100 x 50 cm, black
  • Binding Post PK31, gold plated (one pair, red and black)
  • 1,5m Speaker cable 2x2.5 mm2, transparent
  • Pan screws 3.5x17 black, cross recess, 8 pieces
  • Plan for DIY kit

the crossover components (right),
to be mounted on a small wooden board.

  • Audaphon MKP CAP Superior 4.7 uF / 400 Vdc
  • 1.0 mm air core coil, 0.22 mH/0.21 Ohm
  • Metal-oxide resistor, 10W 12 Ohm (brown-red-black)

Kit without cabinet, price per speaker   EUR 196,00 excl. VAT: € 164.71 / $ 186.12

Kit with high-end crossover

The high-end kit comes with Mundorf MCAP supreme, high end resistor and Mundorf copper foil coils for minimizing microphonic effects. - The current flow through the coil creates a magnetic field which sets the reel of wire in motion. This motion induces a voltage in the coil which adds itself to the signal. The stiffer the reel of wire is, the less the signal will be altered.

Kit with high-end-crossover without cabinet, price per speaker   EUR 228,00 excl. VAT: € 191.60 / $ 216.50

Impedance correction

If you want to use a valve amplifier with this speaker an impedance correction should be employed. In this case the component quality is less important; therefore, we offer only one kit (upon request higher quality components are available).


Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 3,54 excl. VAT: € 2.97 / $ 3.36

universal PCB

If you prefer to mount the crossover components on a 159 x 127 mm universal PCB instead on wood:
Universal PCB RA160, order no.. I-2766, price per unit:   EUR 5,10 excl. VAT: € 4.29 / $ 4.84
We recommend one board per kit (two boards for a speaker pair)


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