Xavier,
I just got 2 sets of Altec 755c's and I'll send the person who gave them to me a set of these installed in cabinets in order to earn the second set for myself...
Was also thinking of presenting the same offer to the person who is willing to purchase 2 sets of Feastrex D9 Monster Alnico drivers and give me one set of them in return for some absolutely awesome cabinets for the owners' pair. Word on the street is that this particular model is very affordable right now as the permanent magnet versions are being discontinued in favor of an all electromagnet product lineup. I, however, am privy to the fact that these MA's are really really good sounding. And I also already own an electromagnet 5," so why not round out the stable a little?
I bring it up to you though as if you like the 755, then a 9 inch Feastrex will just flat blow your socks off. (but hopefully not your budget). They too get right to the heart of the music, but they just have immensely greater resolution, dynamics, and are also non fatiguing. The 755 actually served as inspiration for the Feastrex designers, so much to the point that their "Type I, II, or III" electromagnet circuits are almost the same shape as the 755 electromagnet.
I worked with the Line Magnetics 755 electromagnet last year and it was alot of fun, actually. My initial impressions were somewhat luke warm in terms of their price to performance ratio, (and lack of high frequency extension/refinement, and minor hiccups at 3k)...(however...don't get me wrong I VERY much enjoyed the musical things that those drivers did well!!!) And you are so right - that they make themselves easy to listen through their faults. Good points that outweigh the bad. And it seems that the speakers I built have improved greatly anyways after a full breakin process. Enough so that I've reconsidered the situation that I probably owe it to the driver model to give them another chance.
So we'll be making an aperiodic for the 755c's we've gotten in. Should be a fun project. I like classic audio sound very much. It is so important as a designer for me to keep one ear turned back to history in order to effectively shape the things to come in single driver technology. So I've embarked on these classic speaker cabinets in the manner that I am definitely looking towards the future - to do justice to the Feastrex 5"s and 9"s.
Cheers!
-Clark