My concert, tenor and baritone designs use cantilevered fretboards. As with many things in instrument design and construction, it just isn’t possible to know with scientific precision whether lifting the fret board off the top improves the sound of an instrument. Any acoustic instrument is a complex system with many variables that are difficult to evaluate in isolation. However, experience suggests that the extra effort to cantilever the board may pay off. Here’s the logic. Virtually all of the sound is generated by vibration of the top when it is excited by the energy of the strings that is transmitted to the top through the saddle and bridge. A ukulele top doesn’t have much area compared to a guitar and the more it is free to vibrate, the better. It has been argued that the upper bout doesn’t contribute much if anything to the sonic output. While this may be true, it is also true that if the upper portion of the top is firmly fixed by the board, the adjacent area of the top from the sound hole down will be at least slightly inhibited from vibrating as much as it might if the whole top were free.
Cantilevered boards are found in a few other ukuleles and in some guitars. Other small instruments that use cantilevered boards are violins and mandolins and given the untold number of these that have been built this way for hundreds of years, it can hardly be considered a radical or unproven idea. That’s not to say that ukuleles with cantilevered boards are necessarily better than conventional designs, only that my way of doing it can be one of the paths to a good outcome.
So why don't my pineapple ukuleles use a cantilevered fretboard? Because on the pineapple, the fretboard overlaps the top no farther than the internal heel block so cantilevering it would not affect the ability of the top to vibrate.
Rick Turner has built quite a few of his Compass Rose ukes with cantilevered boards and has something like fifty years of instrument building under his belt. Here are some excerpts from his posts on UU:
I do not believe in the "neck/fingerboard transmission of vibration into the body" theory. It just doesn't hold up when you look at alternatives. And, if anything, gluing the fingerboard to the top prevents the upper bout from vibrating effectively.
Just my way, just my opinion, your mileage may vary.
[T]he real player Martin ukes are the simpler ones with the very short fingerboard extension. Now why would that be?
When I designed the Compass Rose ukes, I'd already been freeing the fingerboard extension on my acoustic guitars by cantilevering it. I knew it worked, and there is close to 200 years of precedence doing this going back at least to Stauffer. So it's actually a traditional way to build, though rare. With some modern technology...carbon fiber...it works better than ever. And then my good friend, Ukulele Dick (aka Rick McKee), a fabulous uke player and collector (about 250 vintage and new ukes in his collection here near Santa Cruz), told me that the best sounding ukes did not have a fingerboard extension glued to the top. Bingo...for me it was a no-brainer to just apply that cantilevered fingerboard concept to a tenor uke design, and now to my concerts and baritones. It gives the best of both worlds...more vibrating area plus the extended note range.
Of course many of the early Hawaiian ukes didn't even have separate fingerboards...the frets were just banged into the top surface of the neck, and the 12 fret went right at the neck to body joint. The couldn't exactly saw fret slots in the top...though that was done on some early lutes.
Please remember that this is a sales thread and not a forum to debate the merits of a design philosophy. I only put this info up because I was invited by the seller to do so.