3 way with powered sub, which midbass?

[JFE]

Hello everyone, this is my first real post. I have lurked around here for years, but have always been able to answer my own questions and have never really had anything to worthwhile to share.
Anyway, since I have woodshop this semester, and it is finally my senior year. I will most likely be going to Michigan State University next year to study electrical engineering. sorry got off topic. What I was going to do is make a 4 way speaker that would really be a 3 way with an attached sub actively crossed and attached to an amp that has yet to be built. I was thinking an rss390hf for the sub, sealed, one per side, would 250-300 watts be sufficient? Probably would build something along the lines of an lme4702 type of amplifier, it seems like it would be harder to screw up and cheaper than a more discrete amp.
For the upper octaves I was thinking rs52 for mids 1200hz or so to 5khz, and either the sb acoustics sb29rdc or vifa xt25 because I have heard the vifa and love it, but I would like to try something different but similar. Now for the dillema, what midbass would be most suitable. I have considered the sb17nrxc35, the peerless exclusive 7" 830883, the scan speak discovery 18W/8434G00, and either 2 rs150's or 2 rs180's... I don't know which would be best. I want to have these either sealed or open, I don't really like ported alignments much.
My school has a large cnc router, so I am really thinking about stacking mdf into layers to make a good diffusive interior with no parallel sides, and a nearly spherical baffle to minimize baffle step and any other types of diffraction. I will do my best to time align them and try to keep the phase coherent, but hey, i'm just learning. To power the upper half of this design I am probably going to build some sort of Aleph, as I already have the boards and from what I understand they sound amazing. I do want to keep it all under 2500 dollars, these will probably end up in my parents living room, but I need something to do and I REALLY want to hear something like this. Any help would be appreciated, and I will let you know how it goes. but it will be a while, probably several months.

[Brett]

Here's the first recipe I came up with given your budget, and my tastes.

LF: AE AV15X, sealed 65L+ net gets an f3 of 48hz, Q=0.707. Add an LT to get 35Hz or so if you want. Xover at 200-300Hz to...

MF: AE TD10M, xover at 1500hz or so to

HF: B&C DE250 on a DDS ENG 1-90 Pro or QSC 446 WG

Add a Behringer EP2500/4000 (with fan mods) for the LF, DIY a discrete or opamp based active xover and build whatever amps you want for the MF/HF with the leftover $.

LF ($438/pr ), MF ($488/pr), HF 1" ($240/pr ) and DDS ($192/pr from here) or QSC (about $40/pr) and EP amp (~$300). Total of $1506 (QSC) or $1658 (DDS).

[JFE]

That does seem like it would be a worthy combination, but my only concern would be about the tweeter. How would it compare to the xt25, anything more harsh than that tweeter can be irritating to me after a while, tried on a few different amps. I have tried it on my gainclone, my dads Rotel, and my cousins Parasound, which used to be my dads but that big beautiful amp wouldn't fit in my mom's new cabinet... Darn! I had to go amp shopping. ha.. a little sarcasm there
So I will keep that combo in mind, but any thoughts on what midbass would be best? I know this may be stupid, but I like to keep bandwidths for drivers narrow and the csd clean, but I also want low distortion, I may not be able to hear a difference but at a psychoacoustic level knowing that something measures better gives me a better preempted opinion. I shouldn't comment on wide band drivers however, I have never heard a well implemented full range.
please keep the ideas coming people, I want the best I can get for my money.

[carlomar]

Hi,
I have Xt 25 and SB29rdc in 2 way.

I like XT but like SB best.

Great Tweeter.

[David Gatti]

Looks like we think alike.
I think the Scanspeak revelator or Illuminator are the ideal solution (and what I'm using).