[quote name='Bill Fitzmaurice' post='939745' date='Aug 30 2010, 02:22 AM']You're on the right track. If a carbon fiber neck is solid it's flawed, as that doesn't take advantage of the stiffness of the material.[/quote]
Steinberger necks are solid and are some of the best sounding and responsive graphite necks ever produced (IMO). However they are a completely different manufacturing process to monocoque "semi hollow" equivalents. While structurally rigid, monocoque construction doesn't always make for a pleasant sounding neck. However the most advanced monocoque designs (such as Status necks) incorporate fill material that selectively dampens some unpleasant frequencies.
Technically superior doesn't always mean better sounding.
I believe honeycomb construction for speaker cabs was discussed on the Talkbass thread but gluing the material became quite critical to its success. Thing is when you push the boundaries of any construction process, the costs go up as the manufacturing process becomes more sophisticated.