I'm running my system actively, using digital active crossovers and equalization via the HDMI output of my Mac Mini. It's definitely not high-end. The speaker arrangement is unorthodox. I'm using a matrix of 3 speakers for everything above 220Hz. These are all right next to each other, at 1 foot center to center distance, and all mounted on a single 2' x 4' board. The drivers are 10" midwoofers - open baffle, placed close to the back wall (because I have to) with absorber panels behind them. The 10" woofers go up to about 1200Hz, where they cross over to some horns, which are PT waveguide clones with JBL 2426H compression drivers placed directly above the midwoofers on the same baffle. There are capacitors on the horn drivers, which keep them safe and act as a pretty good EQ for the constant directivity waveguides, and keep amplifier hiss below audibility. 

My 3 speaker array, it achieves a wide soundstage through crosstalk reduction, which works better than I expected. The array mix is L-R, L+R, R-L. The idea was I wanted a center channel, and was wondering how much stereo effect I could retrieve with the side channels that didn't duplicate the center imaged sounds. I thought it might work with the speakers pretty close together, and it works really well! The reason I'm using the direct radiator 10" midwoofers is that I can't get a horn small enough to fit the 1 foot spacing. My calculations suggest that the wider spaced horns at 2' center to center spacing could still produce a wide stereo soundstage. I experimented with spacing the midwoofers futher apart than the tweeters, but that sounded odd. Center panned sounds did not seamlessly match side panned sounds. I'm wondering though if I could do a partial horn loading by placing all 3 woofers in a slot. So, they'd be loaded vertically but not horizontally. I've seen other manufacturers do things somewhat like this. I think Oswald Mills has a speaker that has wings going off the woofer that tilt to lightly load the woofer horizontally but not vertically. 

For the bass I have some corner horns, which are comprised of four cabinets stacked on top of each other. They're triangular shaped to fit in the corner, and use a split path folded 6' long horn. Each are driven by an 18" woofer. These are limited in the bottom end to about 30Hz, mostly due to the small backchamber size, according to hornresp simulations. They also have a problem with cancelation and resonance somewhere around 80hz. I don't fully understand this yet, but it seems to be a problem with the horn mouth being too narrow for the length of the horn, which has about a 6' path length. These bass horn stacks have a cabinet in the middle which contains a 2' long midbass horn that was designed to cover 200 to 2000Hz. This also has a coaxial tweeter horn right in the middle of it. These horns have problems, as you can imaging, with very uneven dispersion, with the midbass horn getting very narrow at 2000Hz, and then the tweeter starting out very wide above that. I did some testing to see what the midbass horn would do down in to the bass range, and of course it falls off dramatically below 200Hz. Interestingly, down at 80Hz it shows the same deep cancelation as the bass horns. Perhaps it's because of being right in between the bass horns. Perhaps I need to remove it from the stack and play it on its own to see if that's really the case. 

Anyway, my center array sounds much better in the mids and highs. The bass horns are flawed, but still quite beautiful and majestic. I prefer them to any non-horn loaded bass I've heard so far. With some EQ I've gotten them to measure flat down to 10hz according to REW. That means EQing the higher bass frequencies down a lot and then cranking up the gain for the associated channels on the receiver, which is just an old Denon 7.2 Surround receiver I got for practically nothing on craigslist. Since the horns are so efficient I can get some earth shaking bass and very loud playback without much amp power. I don't do that because on most music I'm perfectly happy if I can get a little below 30Hz before it starts to roll off, and I just feel better about not applying such drastic EQ.

Pardon my late reply, and thanks for your remarks! What are the particulars of your horn/direct radiator/horn setup, and are you running it actively or passively? 

Prior to my current main speakers I used passively configured all-horns, Simon Mears Audio Uccello's, which are an homage really to Paul Klipsch's Belle model. They were lovely speakers in places, but the bass horn was too small and had some upper bass peaks (~125Hz region), which marred the overall presentation with a chesty coloration. However it was still a bass horn, and the bass and lower mids quality and that special, organic "twang"-feeling - apart from the peak resonans in the upper bass - was great. Lovely mids too. 

It goes to show though a front loaded bass horn must be non-truncated and load properly in its entire frequency range to uphold both sensitivity and smoothes of response, and that takes more size. Same goes with a midrange horn, ultimately. Large direct radiators instead, as you've found out yourself, are a nice compromise. High sensitivity dual 15" pro mid-woofers per channel, not least high-passed >80Hz, can be seriously imposing in a domestic environment when fired up, but what surprises me is how well-behaved they are up to the ~600Hz range where they're low-passed in my setup to the horns above. More important they, like a mid bass horn, energize the power region in a way that smaller, low eff. woofers simply cannot equal. It just sounds more real. 
Ultimately I'd go with a properly sized, non-truncated midbass horn for the simply reason that I find they sound even better in this region, compared to anything really. The smoothness, clarity, vibrancy, dynamics and natural warmth that can be achieved here is downright outstanding. Someday I'll go there again - properly, without size restrictions. 

I've chosen tapped horns for subs duties being that a non-truncated FLH down to 20-25Hz would be about twice the size of the TH's I have now - simply impractical. Less extension with a non-truncated FLH would do - say, with a tune in the 30-35Hz region. Most importantly, I find, is choosing high eff. sub solutions (>95dB's) to attain the most natural and effortless reproduction, and there's a variety of ways to achieve this. TH's have excursion minima at the tune, and that offers some advantages in the lower octaves in particular, while having, fundamentally, the characteristics of a FLH. 

Pardon my late reply. Oh, I love my Belles SA30, so I can understand why you're very pleased with the SA100 - being they're so very much alike with one being class A and the other A/B. Apart from that they're virtually similar. These amps combine musicality and insight/honesty in quite a singular way, I find. What speakers do you use with the SA100?

It's a very rewarding system to listen to, never tiring, and hard to leave. I listen late at night. I wake up in the morning many times and the system is still on, but that is the time when I can enjoy it intensely without disturbing anyone.

 I've just got to keep everything working, which over years in time takes some effort, and a fair amount of money. It's worth it, though.

best regards,

Dan 

Sorry for never getting back to you until now! Thanks, it's a powerful and, sorry to be immodest here, very well sounding setup - I certainly find so myself, and (audio-)friends of mine also. One mayn't expect pro cinema speakers to be a natural fit in a domestic environment, nor 20 cf. tapped horn subs for that matter, but overall the sound is actually very resolved, coherent and tonally quite accurate. 

I looked at your setup as well, and it looks to be an extremely musical system - kudos! At one point I may explore going analogue (i.e.: turntable) again, but that's not in my current plans. 

Regards,

Mikael

Man, you are one horny dude! I mean that in the best possible way! I think your horns would be a very good fit in my home, with my equipment. I'd enjoy hearing them..

Very nicely done, enjoy! Regards,

Dan