"I don't necessarily agree with either point.
Yes, I think larger horns with a lower cutoff are desirable, because they let you control directivity down to a lower frequency. But a waveguide that gives good control below 1kHz or so will be quite wide. A friend of mine who was probably one of the first in the world to use the BMS 4590 dual-concentric compression driver in a home system (late 1990s/early 2k's) gets good directivity control down to something like 700Hz. His 90x40 waveguides are something like 2' wide.
As for the "squawky" factor, that has much more to do with waveguide geometry than with the size of the compression driver. In a well-EQ'ed constant directivity horn, it's not an issue. See the GedLee Summa as a prime example."
This interesting. I will definitely take this into consideration in the future. I have a pair of EV-DH1012 with HR 9040 horns that are very large. They have a 1" throat and would probably be inline with the characterisitics that you outlined. I have had pretty good luck crossing them over at points as low as 350Hz. Like I say though, the HR 9040s are BIG. 40" x 18". With the driver they weigh around 40 lbs. I picked them up at a pro sound company for $250.
My problem has been the bass region. I have vintage (old) E140 15" drivers in short-throw bass bins. Crossing them over above 500hz in a small listening area is where I have had problems with muddiness in the mids. When about 20' or more away from the system crossed over at 800 and 4500Hz for JBL 2402 bullets, this is not a problem.
I am completely hooked on horn systems. I know this site is not specific to these systems, and there are sites devoted to them. But, I had to reply when the original thread brought them up. In my experience horns have a detailed and dynamic response that cannot be matched.
I have considered making some diferent cabinets to use the EV horns and bullets with and replacing the bass bins. Another problem with the bass bins is there size.
Maybe I should consider a pair of 10" drivers that would go up to 800Hz or greater, myself.
Since I was unhappy with the sound using passive crossover points of 800Hz and 4500Hz, I could try lowering the Low-Pass cutoff and the Low-pass section of the band pass filter. But that doesn't solve the problem of size with the bass bins.
For the time being I switched back to a smaller dynamic cone 2-way system with HiVi Research 8" and Morel MD-20T dome tweeter. They sound okay, but the sound does not jump out at you like it does with the horns. Until I switched to using a cheap Harmon Kardon AVR-146 to get surround FX, I used a QSC RMX 1450 to drive the bass bins and either a Hafler DH-220, or Ramsa P1200 to drive the EV horns and a bridged BGW 250E to run my subwoofer. I used a cheap Behringer crossover that was surprisingly flexible and uses very nice op-amps and Alps pots in its design. It was a decent system for stereo reproduction. Unfortunately I did not get an AVReceiver with pre-amp outs. I was wanting to try using smaller speakers, but have not been entirely pleased.
It's an on-going project. I work with one system for a while and then try something else.
Have a nice day