The different projects


New horn project. A classic about 50 years old. A backloaded horn for 12" drivers. It is acually built in soft board and then has a shell of chipboad around it.

 I had some initial trouble as the horn is made for rearmounting the drivers and the lid is to small to fit many of my drivers. So I made a external baffle that could take drivers either way. The baffle was screwed and sealed to the front.

The first driver that I tested in this horn using Omnimic and Woofer Tester 3 was the Bulgarian Gamma LA1232, that worked surprisingly well in the Kuben horn. Low Fr of about 30 Hz huge Vas of 300 liter and moderate Q of 0.4 hardly a classical horn driver

This is how the near field response is mid center about 5 cm in front of the dust cap

Mouth opening in the middle (all measurements on the same spot.

Falls  rapidly below 50 Hz and has some  4 dB peaks at 55 and 90 Hz. The sound is surprisingly good with those soft board panels I expeced no bass and all buzzing vibrations but it does not sound that way. The Klinger is about 300 l and the Kuben about 200 l so I had higher expectations than that on the Klinger, perhaps an other driver...


  1. Nice tests, but the Klinger horn was designed for an 8-inch element*, was it not? Using a larger element will give you a hump in the midrange.

    Best regards,

    Peter Akemark

    */ The T/S paramenters for the elements at the time are not very exiting ones, Qt around 0.5 and Vas below 50liter and a Fs around 30-40Hz
    Look for something like an Isophon PS 203

  2. Dear Peter they do have similarities but the Klinger here and the Schmacks you are thinking about are two different designs. I was surprised at first that the Beyma that gave the weekest bass in the Kuben gave the strongest in the Klinger. The reason could be either the low Vas or the low Q. Adding a serial resistor would then have showed if the low Q did it but the horn is no longer in my possesssion. It could be that the stiff suspension gives some reactance annulling similar to the back chambers of frontloaded horns.