It seems like I’m the only Oris 103 user (and I’m not really following Bert’s current way of working)

I’ll give a short resume of my adventures with a set of prototype Oris103’s:

Early 2001 I bought a set of prototype Oris103 horns and started experimenting with the ACR FE103Sigma speakers I had.

Because of the long horns (ca 52cm) the response dies above 10kHz, so I needed tweeters, Visaton DHT9.8’s seemed a good idea. For bass, I tried a pair of Bert’s Onken cabinets with Vifa speakers but decided I wanted to build ‘real’ bass horns. I started surfing’ the web and reading all the horn-literature I could find, after a few months I started designing 50Hz bass horns with Eminence Kappa 12 drivers, see picture below. Bert measured these and it turned out they were quit flat 50-250Hz.

Time alignment is a problem with long bass horns, so I used a Behringer DSP8024 to delay the mids. January 2002, I didn’t like the vibrations that the FE103 transferred into the Oris 103 horns and made a wooden cylinder, filled most of it with polystyrene foam (Dutch: piepschuim) but left a space of 3-4cm between horn and foam, this space was filled with dry sand. The result of this modification was amazing, coloration was greatly reduced.

August 2002 brought modified Audax PR120i’s tweeters, these match the Oris103’s better in efficiency. I use a passive filter at 10kHz on them. This setup was used for a few years with a lot of fun, every tweak in the chain could be clearly heard.

August 2003, Behringer had just introduced the DCX2496 digital crossover, I couldn’t resist this great little toy and gave myself a birthday present. It’s great to hear the effect of different filters/delays/eq’s etc.

Summer of 2004, I got curious about open baffle dipole bass after reading all the enthusiastic postings in the various DIY forums, I did a quick experiment with some old 12” drivers in an old tabletop cut in two pieces. I was sold within three minutes, no more honky colorations and the room modes were less apparent.

November/December 2004, dipole implementation with Visaton TIW400DS, one voice coil driven, with a little eq fom the DCX, great bass from 20Hz up! I’m really happy with this setup!

The attention is finally going to the music and not to the system. Next step will be modifications in the Behringer DCX2496, new Tentlabs clock, output transformers, etc etc.

Peter van Vegchel, the Netherlands