Metal cabinet speakers

jon is right. Look what Magico has to do to quiet things down. These guys must love to do CNC machining. That would be the only reason to make speakers that way, YG also. Great speakers if you can afford them.
Wilson's solution of using composites to make individual small enclosures is a good one. MDF is just as good you just have to increase wall thickness and keep the enclosures small with rounded edges and flush mount drivers. Finding great drivers is easy the problems come in designing the crossover. 

kenjit, it is easy to build passive cross overs. First class parts are ready available and the math is not that complicated but unless you stay first order phase coherence and efficiency matching drivers with various impedance curves without adequate test equipment is virtually impossible. The easy way around this is to use active cross overs and bi or tri amp. My favorite way of making a very high quality system for friends with a limited budget is to make a D’Appolito array using two 6” drivers up an down from a dome tweeter on a plate sandwich of MDF and solid surface material. I’ll use a simple 6dB/oct cross over and tweak it measuring the frequency response until I get it reasonably flat. Then I’ll cross over to subwoofers at around 125 Hz. You can mount the plates on stand but my favorite stunt is to hang them on chains.

Unsound, I am only referring to the positioning of the drivers. Done this way the drivers are acting acoustically as one driver through the entire pass band, an almost perfect point source. Whether or not you use a 1st, 2nd or 3rd order cross and where you put it depends on the physical size of the tweeter as you want to keep the mid/woofers as close together as possible, the upper frequency limit of the mid/woofers and the lower frequency limit and power handling of the tweeter. If you choose the right drivers you can get away with a 1st order cross and still maintain the point source characteristics of the array. It does limit your choice of drivers generally to more expensive ones but it makes life much easier and guarantees a phase coherent speaker. The dipole plate design eliminates enclosure resonance and improves integration with the room acoustically. Placed at shoulder level these little speakers sound really big. With your eyes closed you would swear you were listening to big floor standers. 
If you have access to a CNC mill you could even make the plate out of aluminum.

geoffkait, notice the two "f"s. Just went to the Audiomachina web site. Interesting design. I like that it is a line source and I like that it goes into corners although that will cause issues with some rooms. Question, what are the 1/2 inch diameter black bumps on either side of the drivers? 
Are the three or so inch drivers run full range and if so I assume the amplifiers are equalized to some degree?

Mike

Can I sell you a CD Re-animator? Or maybe some Dark Matter Optical Treatment. I thought you had something to do with AudioMachina. I had never heard of them. So, now I won't offend anyone??? Running a 3 inch driver full range is almost the silliest thing I have ever seen even if they are forming a line array. This is Pipe Dreams meets Bose. Sort of like crossing a rhino with a giraffe. Their horizontal dispersion above 8 kHz will be offal (intentional))) and everything will be Doppler distorted from the bass. Even if you crossed to subs the high frequency dispersion will be so bad that the listening position will be limited to exactly the spot where the beams cross. 
Judging by the lengths they went to to make this speaker it must cost a fortune. Either a SoundLabs or Magnepan 20 or 30 series speaker is going to out perform these things for probably much less money. I don't want to jinx anyone but I doubt these guys will be around long.  

Geoffkait, when was Klipsch founded. I do not know the History of Audio Machina as to when they first released their product but unless they come up with some low end products that regular folks will like they will be history just like Nearfield Acoustics. If I suggest a linear array speaker I will go with ESLs or ribbons. Maggie 20.1s out performed the Pipe Dreams in every way except volume and the same is true with these Audio Machina things. The Maggie ribbon tweeter is the best tweeter made even better than ESLs due to its wonderful dispersion characteristics. If you look at the physics stacking dynamic drivers is a silly endeavor. There is no driver narrow enough to work. A dome works fine as a point source. Maggie's ribbon tweeter is 1/4" wide and radiates over 100% of its surface area. It is also long enough to function as a linear array over its entire frequency range. Perfect. The only sad part is the woofer is not...long enough. Because the speaker is a bit over 6 feet tall it functions as a line source down to somewhere between 150 and 200 Hz. The best way to deal with this is to make the speaker 7'10" tall so that it abuts an 8 foot ceiling. Then it will be a line source down to 1 Hz. Magnepan thought about doing this but they thought it would decrease their Market I guess because it would make the speaker more expensive. Good magnets are not cheap. Pity. Subwoofer systems just do not function well up at 200 Hz. So, when I set up Maggies I keep the subs point source and jamb them into the corners. I cross at 100 Hz. I guess I am rambling.