Ah, that makes more sense. His drivers should be a good fit for transmission lines (TL). But without knowing the driver specifications it would be impossible to "design" TL for them without creating piles of sawdust.
Until Martin King developed a MathCad computer application, there was no way to design TL on paper. But the math involved is not simple and still involves trial and error to arrive at a proper solution. Note that Jim Salk hires out his TL design work. Check out BrinesAcoustics.com to get a taste of the MathCad design behind TL. I commissioned Bob to build the first M18-F200 speaker (still my babies but the veneer has gotten darker since the image on his site was taken 11 years ago). I've been a fan of TL since Irving (Bud) Fried in the 70's. The bass can be very fast, musical, and powerful. With single drivers the midrange can be cleaned up too with the back-wave being directed away from the driver (cabinet geometry dependent).
Some mention the added complexity of the cabinet, but it's no more so than what's required with proper bracing. (The only speaker cabinets I ever built were TL.) TL typically are somewhat larger than ported designs. As I mentioned above Louis started out doing just stand-mounts to save shipping cost/damage. If you're trying to add bass to Louis' smallest design, I'd add a sub or buy a bigger model. I've seen small TL (Fried Model C that was a truncated pyramid, very complex to build, but very impressive sound/bass). TBI builds extremely small cubic speakers (Majestic Diamond I & IR) they call TL that supposedly delivers amazingly deep bass from a single very small driver and is supposed to be very placement flexible, but I've never heard it.