Relatively small speaker with a "big" performance: Role Audio Starship SE model

It looks like an interesting and different design, and I suppose that maybe the quad transmission line cabinet is expensive to build, because it otherwise seems very expensive for what it is.

the Sampan FTL which weighs 4.5 pounds and is 8 X 4 X 9.5 inches, will show an image of a composite MLSSA measurement of the TL-ABC version that is +/- 3.5 dBs from 35 to 20kHz

The devialet phantom speakers are small enough to be held in your hand yet they can do 20hz bass. So obviously these sampan speakers are not very good considering what the phantoms can do.  

And if someone was touting the Devialet Phantoms kenjit, you'd find a speaker the size of a thimble that was better...Please.

And you can’t hold a devialet phantom in one hand.  2 barely.  They’re pretty heavy and are unique in their bass output and volume output.  
They are not the last word in refinement.

@kenjit , have you hesrd the Devialet Phantoms?  What were your impressions?

Yes Duke, very intriguing design. Getting a transmission line right is not easy at all. Usually it becomes trial and error. The math only gets you near the ball park. The other problem as you mentioned is the bandwidth problem. With a 6 dB/oct crossover you would have to keep the crossover high to prevent overloading the tweeter. So either you are limiting the headroom of the speaker or you are asking the woofers to run higher then perhaps they should. If this is the case then a subwoofer system crossed on the higher side will help a lot. Otherwise, this speaker should image well and certainly has enough midrange power to go convincingly loud as long as the tweeter is kept out of the action. I'm surprised they did not use a 12 dB/oct crossover. Using an active digital crossover and biamping would be a natural for this design.