It appears those speakers, Acoustic Energy, have metal drivers. Its certainly not the best material for a mid/bass, woofer, midrange driver. Its a strong material and offers the greatest amount of mechanical motion to sound transfer, i.e. they don't bend absorbing/losing some of the pushing force from the coil (I didn't say it well), but they completely lack any internal damping and this is why they just don't sound good. Granted some metal drivers are better than others, as there's more to the driver than just the cone material, but its a safe generalization in my book to avoid any metal/alloy (or ceramic for that matter) drivers, especially with what your doing and want. I've even seen $80,000 systems using them and I'm not sure why. Carbon-graphite, polypropylene with mineral loading, and well-treated paper cones are about the best three, maybe in that order. Kevlar's not a very good material either, so stick with "conservative" three. But that's probably why you're hearing a "lack of warmth," the coloration of that metal. It can be great for tweeters though.
For your price range you may also want to lean towards a bookshelf design. Floorstanders become exponentially more expensive to build, if cabinet resonance are to be controlled, and a good bookshelf can offer just as much bass, if the designer is willing to trade efficiency (all things being equal), but deliver better sound on up, like the detail you want (the designer tood that saved cabinet money and reinvested in the tweeter). But don't let me get too....I don't know the word.. if you like floorstanders I understand.
It sounds like what you really need is a good transmission line. That'll give you a nice two way floorstander with some real bass, and they don't suffer from cabinet resonances like bass reflex and sealed enclosures. Only problem is, there've never been many commercial offerings. TDL did'em for years but I don't think they are in business anymore. And Focal had the Daline 3.1 and another several years back. They certainly had bass for those little drivers, but its been several years since I heard'em. I believe there's a website called http://www.t-linespeakers.org/index.html There's alot to look at there and might point you in the right direction and even David B. Weems' book has a little TL project. But my general advice is, avoid the "high tech" materials and look at bookshelf designs to get the best product for the money. Take your time and maybe get some free auditions under 30day returns to get an idea of what you like and what's possible while retaining the security the diy route lacks.
Sorry I couldn't give a specific product recommendation (well I could, but I get tired of hearing myself say the same things and sound narrow-minded, and even I'm not for certain), but some general knowledge can get ya going.
