I heard a set of the Jordan JX-92 drivers in a pair of ported boxes built by Dave Elledge. These things really impressed me. They aren't the end of the world in terms of information retrieval or frequency extension, but they have a smoothness and a coherence that sounds right. They are missing the bottom octave and arguably the top octave, and they have a touch of zippiness in the upper treble. That said, these drivers make for some very enjoyable musical speakers. Given my penchant for transmission line bass loading, I decided to use them in my Minimite hybrid ESL's. The good sound of these things through the midrange and their outstanding Xmax, made them a good candidate for use in the bass of a very small ESL. I've been working on other projects rather than finishing the Minimite project. From time to time I'd listen to the JX-92 TL's by themselves. They consistently have proven themselves enjoyable and musically satisfying. I have always wanted to build a very small tidy system in the spirit of British audio gear (like Linn etc).
I designed a set of floorstanding enclosures which are as small as possible. The design shown here are seven inches wide, seven inches deep and thirty eight inches high. The transmission line is 68 inches long, and is stepwise tapered starting at 2.75" wide, reducing to 2.5" at the turn at the base of the enclosures, followed by 2.25" exiting to the port in the back. The front corners are rounded using a 3/4" radius roundover bit. The enclosures shown in the following photographs are finished with a pecan veneer. The plans for the enclosures I built are included below.
A simple baffle step circuit is shown below. This is based on a multi-tapped inductor to allow for adjustable baffle step compensation. The inductor is a Madisound 16 gauge air core unit which I unwound and added taps to. A rotary switch is used to select the tap or to defeat the circuit entirely. The circuit is shown below (this same concept could also be done with a fixed inductor and several resistors):
Here are some measurements of the speaker. These don't look particularly good on paper, but the speaker does sound better than the measurements look. this is a bit of a lunatic fringe type of speaker much like Lowthers.