I have built a pair of transmission lines using the Fostex FE167e, which, sadly, is not longer produced, modified with hand-turned Planet 10 Hi-Fi phase plugs.
I kept them toed-in by about 15* for dispersion purposes. Really great sound, every single person that stopped by to hear them would ask "where's the sub?" Some car audio guys would say "what's in the crossover?" I would answer that I basically had them corner-loaded for 1-2db of bass reinforcement, and that they ran wide open from the terminals. Great, great speakers. Do excuse the "finish," as I wanted to paint them, but just started to enjoy the bare MDF. Here's a shot of them in my sophomore dorm room in 2009:
The amp is ultralinear, so it didn't sound all that "tubey," and I liked it that way: the inverted surround had very little excursion but those TLs with the corner loaded placement would hit 45hz all day (and did!).
If you can find a pair, I would jump on them. They were not all that expensive, maybe $60 each IIRC.
My junior year I got into the JX92s, and I would highly recommend that you do, too. These were built and traded to me by a master woodworker who makes ultra-high end furniture in NYC:
They are absolute stunners. Flush-mounted in MDF with a thick veneer of grain-matched Macassar Ebony, coated in Tung oil. Running wide open, of course. They're an MLTL design, and I love them dearly. The Jordan drivers are really technical achievements, I urge you to jump at them as soon as you are ready. For about three months I had these coupled to a pair of 15" drivers, running open baffle in an H-frame mount. They turned out to be really muddy to my ears, and I gave them away to some high school kid on Craigslist so that he could have the coolest truck in town...
Oh, and remeber, there is an established deisgn that utilizes a ribbon tweeter in conjunction with the 92s, which I bet sounds quite good.
I used the JX92s set from about four-to-five feet out, and was very satisfied. I found that the Fostex set needed maybe seven-or-so feet to come into their own, perhaps due to the whizzer cone.
[I still have both pairs, with the drivers boxed should you be interested, BTW]
To recap, I think that the JX92s is the way to go. The only drivers I would take before them would be some crazy exotic field coils, or maybe some ribbon co-ax designs.
Edited by Nick 214 - 6/26/13 at 8:56am