BK 201 KH - Jabo Spherical Wave Horn with bass horn classic by Fostex as in Hobby Hifi 6/2007

Technical data:
- bass size (HxWxD): 90 x 28.8 x 40 cm
- HF horn size Horn (DxL): 53 x 53 cm
- impedance: 6 Ohm
- crossover frequency: 700 Hz
- sensitivity: 90 dB (2.83V/1m)
- frequency range (-3dB): 30-17000Hz
- speaker type: horns

Based on the idea by Günter Damde from Art Of Sound in Saarbrücken / Germany, an imposing twin horn was developed. The crossover was designed by Bernd Timmermanns.

Spherical wave horns are usually found in expensive loudspeakers. However, this design by Günter Damde is reasonable priced and affordable. The speaker system, introduced in Hobby HiFi, allows all enthusiast to realise their dreams.

This twin horn consists of the mid / high frequency horn Jabo KH-53A, made in Oldenburg / Germany with a Fostex D1405 driver attached, as well the Fostex FW 208 N bass horn.BK 201 KH

Excerpt of the review in Hobby Hifi 6/2007

... "We experienced an outstanding clarity and naturalness, displaying an ease that we last noticed when we listened to the top projects like Faktum, Optimum and Audimaxx, as well as the Capriciti electrostats. Three dimensionality was absolutely top, with a stable centre accompanied by enormous width and depth. Vocals impressed with a natural timbre, percussion with terrific punch." ...

There are two crossovers presented by Hobby HiFi; we supply the components to both. The crossovers couldn't be more different. Hobby HiFi describes them as follows:

"There is a snag with frequency response faults: with the right music they might even please the ear. Over the entire musical spectrum, however, they will be noticed as faults. Bass was particularly better with the new crossover design: an outstanding clarity, tightness and an extreme attention to detail was displayed as we expected from a good bass horn. Considering the compact size the low bass of the BK 201, placed 30 cm away from the front wall, was simply astonishing. In fact, this low bass was only produced when our crossover was used, eliminating the booming resonance. In a nutshell: our crossover was more balanced and natural and showed a more three dimensional stage. But only at moderate volumes. The provisionally mounted, reasonably priced ferrite core coils produced noticeable distortion from medium volumes upwards, increasing with rising levels. The sound became tinny and narrow. From a medium level upwards, the original crossover, despite a certain tonal imbalance, performed a lot better. We seldom noticed a more noticeable difference when comparing component quality. It proves that one should not underestimate the influence of higher quality crossover parts."

Our kit contains

- Jabo spherical wave horn KH-53A
- horn adapter and a tilted base
- Fostex driver D1405
- Fostex FW 208 N bass horn
- 1/2 mat Bondum 800 (or nap foam)
- self adhesive sealing tape
- 8 screws 4x30 mm
- 4 binding posts
- 2 m loudspeaker cable 2x2.5 mm2
- building instruction
the crossover components
- 3.3 mH transformer core coil T84
- 2.2 mH transformer core coil T84
- 1.0 mH transformer core coil T84
- 1.2 mH baked varnish air core coil BL71
- 0.47 mH baked varnish air core coil BL71
- 1.5 mH baked varnish air core coil BL71
- 220 uF consisting of in parallel:
  2x 68 + 82 uF ELCO non etched
- 47 uF MKP foil (MCAP)
- 15 uF MKP foil (MCAP)
- 5.6 uF MKP foil (EVO)
- 3.3 uF MKP foil (MCAP)
- 8.2 uF MKP foil (MCAP)
- 47 Ohm MOX10 resistor (yellow purple black)
- 15 Ohm MOX10 resistor (brown black black)
- 4.7 Ohm MOX10 resistor (yellow purple gold)
- 2x 6.8 Ohm MOX10 resistor (blue grey gold)
- 2.7 Ohm MOX10 resistor (red purple gold)

Kit price per speaker without wood: EUR 1284,00

Please not:
If you prefer to mount the crossover components on a universal PCB instead on wood, we recommend 220 x 155 mm universal PCB.
Price per PCB EUR 8,80

BK 201 KH, high end

If you wish to employ a top crossover then our high end version is the right choice. All components are Mundorf throughout:

- 3.3 mH transformer core coil T104, vacuum impregnated
- 2.2 mH transformer core coil T104, vacuum impregnated
- 1.0 mH transformer core coil T104, vacuum impregnated
- 1.2 mH baked varnish air core coil BL71
- 0.47 mH baked varnish air core coil BL71
- 1.5 mH baked varnish air core coil BL71
- 220 uF MKP foil
- 47 uF MKP foil (MCAP)
- 15 uF MKP foil (MCAP)
- 5.6 uF MKP Supreme silver/gold
- 3,3 uF MKP foil (MCAP)
- 8.2 uF MKP foil (MCAP)
- 47 Ohm MOX10 resistor (yellow purple black)
- 15 Ohm MOX10 resistor (brown black black)
- 4.7 Ohm MOX10 resistor (yellow purple gold)
- 2x 6,8 Ohm MOX10 resistor (blue grey gold)
- 2.7 Ohm MOX10 resistor (red purple gold)

Kit price per high end version without wood: EUR 1627,00

Please note:
If you prefer to mount the crossover components on a universal PCB instead on wood, we recommend 220 x 155 mm universal PCB.
Price per PCB EUR 8,80

Impedance correction

If you want to use this speaker with a valve amp, you need an impedance correction consisting of three components:
- 0.68 mH Baked varnish coil/0.7 mm,
- 33 uF MKP capacitor and
- 8.2 Ohm, 20 Watt resistor.

Price per impedance correction: EUR 27,85

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