A few posts up I was asked a few questions, so I'm gonna back things up a little...
is it possible for the driver to get in the way and jam up the horn in some way?
Yes it is, but I think it takes more than most would think. You will get chuffing from the air being cut by the frame spokes (as lilmike said,) before you will do much from the reduction in area at the low pressure end of the horn alone. Obstructions in the throat area should be marginally worse on FR, but it should start in the upper region.
It might be worth sweet talking lilmike into running some sweeps with some simulated blockages to tell the tell.
In some AkAbak sims I tried before I found a 75% blockage was needed at the driver to really do much of anything FR wise. The pressures in the horn varied a little, but not much at all. I wouldn't trust this without a real world test to back it up though. I have about 75% faith in it.
specifically, what do you mean by "...as long as you design the horn that way."?
I find there are four ways a drivers parameters fall in a TH.
1- No good at all.
2- Good with the driver away from mouth
3- Good with the driver close to the mouth
4- A general driver that can swing 2 or 3
I was just stating that there is nothing wrong with the driver being at the mouth, if it gives you the response you are after.
The designs I tend to like in simulation have the driver further back in to extend the lowend and bring up the notch preceding the first sharp resonance though
You can get to the same low corner with the right driver either way. You can't shrink it as much though.
I am not sure what you are referring to at the end there? Which resonance are you talking about? (In HR set the Power to 0 and count the peaks low to high as odd numbers)
. Are you talking about the dip before the always nasty 5th? If so, you just had the enclosure to small, or you need to use another flair profile.