Your Axi2050 is not built to use a 200Hz crossover. Try using some the manufacturer's and professional's advice. The Jubilee uses it to 400Hz. I've heard them online and they sound like a giant set of headphones. 400 Hz is a very reasonable limit. Obviously you can't currently experiment with a 400Hz crossover because your woofer cabs won't allow it.
Build a test cab with some of that cheaper patched up plywood.
A c-c spacing of 34", crossover at 400Hz, with a front firing TD18, might just be the ticket.
Professional - " Moreover, the driver is rated for 150W down to 300Hz, and the diaphragm is large, so for domestic use, using it down to
100Hz or even lower would not be a problem. " Isn't Kolbrek that guy who is highly respected in the community who wrote this highly respected book?
Why do you guys keep ignoring the 15" driver I have, yes, I did try a 400hz crossover., and a 600hz, etc... At that time I concluded that 200hz sounded the best. I also compared the 15" to the dual 18"s and concluded the only difference was that the 18"s had more LF extension. I tried tone burst in the area that the slot should be acoustically loaded, and there was no notable difference between the 15" and slot loaded woofers that I recall.
I would like to try a MTM with a Constant Directivity Waveguide. I will likely, try it, one day.
With current setup there are advantages. Having the Woofer at the floor, (I flipped the PPSL cabinet as seen in the above) provides the best FR, in an untreated room, that is, outside of soffit mounting which puts the woofer, so much at the floor it is in the floor.... Covering down to 200hz on a single axis, provides incredible imaging, the vocals only break single Axis Character, on the most extreme Material, ie Barry White
OK!? Barry broke the Facade, otherwise, the majority of vocals sound as if coming from a single axis, when the Horn is crossed over at 200hz at 36" inches.... At a distance farther than 54" this was not possible with a 300hz or higher XO. I started at 600hz, and kept going lower and was like yeah I still prefer 200hz xo. with just 2 acoustical axi's to recombine, and at such a low frequency, a seamless crossover, is very easy to achieve.
Constant directivity I have not. I do have a very smooth off axis transition. Like super smooth. I cannot show you in measurements until I take them. but look at the polar of the FaitalproLTH142 elliptical tractrix, and consider that is easier for my horn to have a smooth off axis transition because the larger dimensions are more forgiving.
I only sit in the window, which is much bigger than would be suggested by some commenters.... According some commenters, I am being more strict than I have to. I Spent time figuring out the size window I would have at 1m at about 17khz. and it was about the size of a basketball. I find that acceptable... In practice it sounds like the sweet spot is much larger. Some think that I was being too strict anyway
Call 17kHz a limit of a sweetspot?
Above 8kHz local absorption of a generic room goes up significantly.
So even if we don't take our own hearing into consideration, the importance of a super strict constant directivity for 10kHz and above is debatable.
Obviously you shouldn't just let it fly, but there is definitely a lot more room for error.
So I am left with a room power response of a rising DI. As long as I have tuned the SPL at MLP, I don't really think there is a reason for me to worry about my ability to listen critically, in line of being a reference monitor used for studio sound engineering. The Large Width of the front baffles, High DI of the horn, and close proximity make for a very high amount of Direct Sound vs Room. That is exactly what I designed this system to do.