4 way project (long), your thoughts?

[Sheldon]

I've gotten back into audio recently, from a long layoff (kids, job, etc.). I now have the time and interest in a speaker project. I recently injured my neck (surfing), so while recovering, I've been cruising the net for a while, looking at this forum and many other useful sites, reading Dickason's book, etc. Here's what I'm planning:

4-way system which is a hybrid between this project:

http://www.kingston.neostrada.pl/ and dipole bass section from the Linkwitz designs. Lukasz' project used a Raven R2, ATC mid dome, ATC 9" d bass, and 15" bass, with passive xo's.

I would like to use the R2 and ATC dome, and perhaps the ATC mid bass, with either a dual 10" or 12" dipole for the bass section.

I have a very nice pair of 30 watt tube amps that I'd like to use on the upper range and plan to use line level xo and eq for the bass section.

Things I have to decide:

3 way, passive xo's on top with active to dipole bass, or 2 way on top with mid bass and bass on bottom controlled by second (probably ss) amp.

If I go three way on top, I wonder if a more effecient mid bass driver might be better, to avoid padding down the dome and tweeter so much. Something like the 8" Flex units from Skaaning? or would the fairly low Qt of that unit be a problem in the dipole application. It looks to have a very nice broad and flat freq response curve. That, combined with the overlapping ranges of the drivers should allow more options in crossover design. If this driver rolls off sooner in this application, would that make the twin 10" bass unit a better match to cover a higher xo point?

There are many different measurement/design packages available to use in a situation like this, and I almost hesitate to ask the forum's recommendations. To help a little, let me add a bit. I'm willing to spend a reasonable amount to do this right, but I plan to design this set and maybe one or two more. Part of the reason I'm doing this, like many here, is the process of learning something new (learning to use a specific software format doesn't count here). Once I've satisfied my curiosity, I'll mostly move on, so I don't want to go completely nuts buying and learning software that has lots of stuff I won't need. I'll need a reasonable measuring system, and a good xo design system. The system I envision has no enclosures, other than for the bass dipole, and for those, I'd be using published designs, so I'm not sure I'd need the typical speaker design packages, although one that models dipole behavior could be useful (necessary?).

Any and all comments welcome.

Sheldon

[Sheldon]

Rereading my post, it was implied but not clearly stated that I intend to use the midbass on an open baffle, as per the reference and the Linkwitz designs.

Sheldon