Thank you for the input! Wish I could make it out to ultra to see the setup you're bringing.
So I am planning on just replacing the tops but I'm curious. Going off the OP main idea, what would you look for in a mid sub? I'm assuming you will probably see several set ups incorporating the use of them in Florida
If you "have" to have a "mid sub", then I would look for something that has the SPL capability to keep up with the rest of the rig.
It should also be small enough so that it can be close enough wavelength wise to the upper part of its freq band so that can "mesh" with the next higher element.
So what do that really mean?
It means YOU have to determine what "keeping up spl wise" really means-based on the REAL capability of the rest of the rig. Without knowing the rest-there is no guess that can be made.
Same thing goes with the physical size-without knowing what the rest of the rig is-it is purely a guess based on no usable information.
Of course it also depends on what some people "think" looks cool. And if you are going to stack it up-it depends on the rest of the rig and the physical dimensions-what your capability to stack are etc. Is it 1 or 2 people? Do you have a fork lift? and so forth.
The REAL answer depends on MANY pieces of information.
But for me-it is not the approach I would take. But other companies make money off of simply providing products that people want-not what they need or understand.
So why don't we have a system that has subs-mid bass-low mids-high mids-highs and ultra high-all in separate boxes? Because you will never be able to get them to sound correct or accurate-due to the physical spacing-different crossovers and so forth.
Yes it may "look cool" and in real simple "theory" work-UNTIL you start to actually measure it and try to get it lined up-IN MORE THAN ONE LISTENING POSITION!!!!!!!!!!!!
People often forget that there are many people at an event-and with separated devices-that is going to cause notching in the response so it will be different at different seats.
How much of a problem is it? It depends on your expectations.
There have been millions of concerts that have this problem and billions of people who walked away with a good experience.
But could it be better? In most cases YES. But it depends on "what you are after" and people are after different things. To some it is all about the visual-to others it is all about the cost-to others the sound really matters and so forth.
So as usual-it depends-----------------