AOS BK 201 KH without housing

Technical data

Product info

An impressive double horn concept was created from an idea in collaboration with Bernd Timmermanns (HOBBYHIFI), who developed an alternative crossover.

One knows Ball wave horns Up to now mainly boxes in the top price range, we now deliver them at a very reasonable price.

Thus, a kit was born in Hobby HiFi that allows many enthusiasts to make their dreams come true. The horn consists of a mid/high-frequency horn, the JABO spherical wave horn KH-53, manufactured in Oldenburg, to which the Fostex D1405 is coupled. The Fostex FW 208 N is used in the low-frequency horn.

from the sound description Hobby HiFi 6/2007 ...

"We experienced an outstanding clarity and naturalness, a lightness that we had recently experienced with our super projects Faktum, Optimum and Audimax as well as with the Capaciti electrostats.

The spatial representation was convincing with a remarkably stable center location and a wide and deep sound image at the same time. Vocals impressed with natural timbres, drums with unheard of impulsiveness."

... Two crossovers were featured in Hobby HiFi, one from ART OF SOUND and a second from HOBBYHIFI.

The Switches are tuned completely differently.

Mr. Timmermanns wrote: 

"That's the crux of the matter with frequency response errors: with the right music they know how to please. But when averaged across the entire musical Spektrum , they fail. The bass was clearly in favor of the retuning: it shone with outstanding clarity, with a dryness and fine detail that you only know from good bass horns.

The deep bass, which was hardly thought possible with such a compact horn and which the BK 201 produced standing about 30 centimeters from the wall of the room, only became noticeable when our crossover was in play and the booming area was eliminated. It's clear: our crossover played more balanced, more natural and more spatial.

However, it only scored points at moderate volume. The inexpensive ferrite core coils used in the provisionally constructed circuit produced noticeable distortions starting at medium volume and increasing as the dynamics increased. The sound became thick and narrow.

The The original crossover played as soon as it got a little louder, despite their certain tonal imbalance considerably more confident. The difference between component qualities has rarely been as clear as in this comparison. It proves that the influence of high-quality crossover components cannot be overestimated."

The new, better-tuned crossover from B. Timmermanns was of course immediately included in the program.

The buyer can therefore be sure that they are getting the best possible crossover for this dream loudspeaker.

Scope of delivery:

• 1 x Fostex FW208HS
• 1 x Fostex D 1405
• 1 x JABO KH-53 RAW
• 1 x high-end switch components
• 1 x high-end terminal ST-975 GM
• 1 x stand angle KH-53
• 3 m speaker cable 2 x 2.5 sqmm
• 1 Mat Damping 10
• 1 mat Bondum 800