Oka   Floorstanding as in K+T 5/2014

Technical data
  • impedance: 4 Ohm
  • sensivity (2,83V/1m): 91 dB
  • size (HxWxD): 1200 x 550 x 300 mm
  • frequency range (-8dB): 35 - 30000 Hz
  • crossover frequency(s): 1800 Hz
  • speaker type: bass reflex

Oka is a loudspeaker that should be used as wall speaker. To do so there are two possibilities: You can build the speaker as floorstander or you build it as shelf speaker that can be fixed to a wall.

Oka is developed by Dennis Frank und Daniel Gattig as bass reflex system.

Oka contains Wavecor chassis. A 30 mm tweeter and two 15 cm woofer.

The crossover consists of a 2nd order high-pass filter (12 dB per octave slope) and a 2nd order low-pass filter.

The frequency response is quite flat at an angle of 0 or 15 degree, the harmonic distortion is low (less than 0.5% above 250Hz at 85 dB (1m)). The decay spectrum is without any fault.

An excerpt from the Klang+Ton review

"Is it absolutely necessarily to place these speakers directly in front of a wall? Unless you put on Daft Punk's "Random Access Memories", then - yes. As we found out with last year's success of this album by the two French electronic artists, no such thing as "too little bass" exists, even with the free-standing Oka. However: there is still one more thing. If we move the loudspeakers directly in front of the wall, as far as the bottom plate of the stands allow (Note to the manufacturers: the base on the loudspeakers that we tested were unfortunately mounted the wrong way round) then you notice that there is still more air to be moved down below. Parallel to and directly against the wall is only the second best positioning option, turning the speakers facing a little more towards the listener doesn't harm the bass much at all but significantly improves spatial imaging. With the drivers on the inside the Oka produced a huge image with perfect localisation, that, particulary with such playful music as the Daft Punk album, sounds pretty spectacular. Additionally the loudspeaker is tonally slightly on the warm side of neutral. It sounds full, round and pleasant. The tweeter sounds silky and powerful, but does not attempt to set any "height records". Fine, that matches well with the rest. At all times the two 15cm midwoofers are - especially with support from the rear wall dynamically speaking, master of the situation. They also produce a beautifully concise and distinguishable vocal range. What does not do any harm despite their snappy efficiency, is a bit of power. The Oka likes to be driven by a powerful transistor amplifier. Then it runs at its best and grabs your attention with it's robust character, absolutely suitable for everyday use and without any hint of nervousness. Great loudspeakers!"

Our kit consists of

  • Wavecor silk dome tweeter TW030WA09, 4 Ohm
  • 2x Wavecor Mid/Woofer WF152BD06, die cast, 8 Ohm
  • 2x Bass reflex tube HP50, 50x145 mm, black
  • Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • 2x Damping Sonofil 100 x 35 cm for 20 litres
  • 2x Binding Post PK31, gold plated (one pair, red and black)
  • 3m Speaker cable 2x1.5 mm2, transparent
  • Allen wood screws IS 4x16mm, black, 8 pcs
  • Pan screws 4x20 black, cross recess, 4 pieces
  • Plan for DIY kit

the crossover components (right),
to be mounted on a small wooden board.
  • Audaphon MKP CAP Superior 12 uF / 400 Vdc
  • Audaphon MKT CAP 10 uF / 160 Vdc
  • Audaphon MKT CAP 22 uF / 160 Vdc
  • Audaphon MKT CAP 2,2 uF / 160 Vdc
  • 0.7 mm air core coil, 0.33 mH/0.48 Ohm
  • 0.7 mm air core coil, 0.05 mH
  • 0.7 mm air core coil, 1.2 mH/1.08 Ohm
  • 1.4 mm air core coil, 0.68 mH/0.26 Ohm
  • Metal-oxide resistor, 5W 12 Ohm (brown-red-black)
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)

Kit without cabinet, price per speaker   EUR 368,00 excl. VAT: € 309.24 / $ 355.63

Kit with high-end crossover

Our high-end version employs a Mundorf copper foil coil CFC16 in series to the woofer. In series to the tweeter a ClarityCap Type ESA is used. Elsewhere only polypropylen capacitors of Audaphon are used instead of polyester capacitors (MKT). Baked varnish air core coils replace standard coils.

Kit without cabinet, price per speaker   EUR 418,00 excl. VAT: € 351.26 / $ 403.95

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 10,90 excl. VAT: € 9.16 / $ 10.53

universal PCB

If you prefer to mount the crossover components on a 240 x 165 mm universal PCB instead on wood:
Universal PCB RA240, order no.. I-2767, price per unit:   EUR 7,60 excl. VAT: € 6.39 / $ 7.34
We recommend one board per kit (two boards for a speaker pair)


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