I’ve learned that a lot of Audiogoner’s aren’t much interested in DIY, but Linkwitz owners have already built the OB frames for their loudspeakers. Still, assembling crossovers is a more demanding task that glueing and painting an MDF flat pack.
There are a few guys building GR Research speaker kits for guys who either can’t or don’t want to do it. Maybe somebody on the DIY site is offering the same for Linkwitz customers.
One of the reasons I gravitate towards planars is that they provide a sound that is more "seamless", 20Hz to 20kHz not being broken up into as many segments, with the then requisite (often) complex crossover. Full range ESL’s and magnetic-planars reproduce instrumental and vocal timbres in a manner I’ve never heard from a dynamic speaker. I learned that lesson when I sold my Magneplanar Tympani I’s to get a pair of Fulton J’s. Yes, the latter’s RTR ESL tweeters provided greater transparency that did the original Maggie tweeter, and deeper bass from it’s transmissionline-loaded woofer, but at the cost of everything being "cut from the same cloth".
My Eminent Technology LFT-8b reproduce 180Hz to 10kHz from a pair of identical m-p drivers! An 8" woofer in a sealed enclosure for 180Hz down, a ribbon tweeter for 10k up, both with simple 1st-order filters. My ET LFT-4’s do all frequencies from it’s pair of segmented full range m-p drivers. If I was loaded I’d get myself a pair of big SoundLab ESL’s. For around $15k, one can get the Sanders ESL, which I have heard and love. Roger's Music Reference ESL's were on my "to hear" list, but I never managed to do that. @clio09, do you have a pair?