5.25 in. MTM +SUB vs. SINGLE 8or10in. + SUB

If you are going to be using a sub, then most definitely keep the midbass units at 6.5" or less, preferably in the 5-6" range. The upper midrange response is vastly better than an 8" will ever have, and you don't need the drivers to go that low in the bass. If you want a specific recommendation, use the Vifa 13WQ, it is a classic and still one of the best midbass units out there. Look up the Ariel by Lynn Olsen (I can't recall the website), it is one of the best uses of this driver and has a ton of info and support. Even if you don't end up doing this exact kit, it is still a good way to start your education.

Sorry, I had a brain hiccup. Lynn Olson's website is www.aloha-audio.com, the Vifa driver is P13WH.

MTM = MIDbass/TWEETER/MIDbass Karls heres my choices FOCAL 5K4211(5inch poly/kevlar) or 7K4411(7inch poly/kevlar) CABASSE 17M18(6.5 FOAM) SEAS W17E(6.5 magnesium) or W18E(7inch) I'm confident the MTM design is the way to go. Do you suggest the 6.5 is the IDEAL size M/B? I would tend to think the 5inch Focal is too small but could the 7 inch Focal be acceptable? Tough choice all 3 are SUPERIOR drivers! I tend toward the Focal 7K4411 poly/kevlar. any votes well appreciated!

Research leads to the following: PHL1230 6.5 MIDWOOFER 40-4000hz.@93db!!! + RAVEN-2 RIBBON TWEETER 1800-32000hz.@95db.!!! Final choice. (The awesome R-3 is 500-25000hz@100db.!!!! REPEAT 100db WOW! Nothing less than a miracle! But$$$1600EACH! Well worth it!)

I don't recognize PHL1230. Is this Phillips or what? One very important caution: ALL the drivers you have suggested have extremely nasty resonance peaks in their upper range, which is going to require you to use very high-order crossover networks to remove, which is a real can of worms. Having done this for a long time, I can tell you that without access to thousands of dollars of measurement equipment, you will be FAR better off choosing a midbass which is relatively flat through its upper range. This means no Kevlar, no carbon, and definitely no metal cones. Just my 2c, obviously others will disagree. Re the Ravens, haven't tried them but they probably work well IF you can get them to integrate with the cone drivers, not an easy task. You have the additional problem that they are much taller than typical tweeters and in an MTM they will cause problems due to the wide separation of the two midbass drivers. Again, if you want to have some chance of getting good sound, best to stick to good-quality soft dome tweeters since they are the easiest to work with.