I use Lowthers with my Voigt Pipe cabinets, and they are well known to be one of the preferred speakers for SET gear. It is one of the classic combinations. If you don't make your own cabinets, buying pre-made ones can be expensive. Some Lowther models can be 100db efficient, when loaded into a cabinet. This gives over 105db peaks with a 2A3 amp. They will play pretty darn loud and clean with a 2A3. Bookshelf speakers are not really an option with Lowthers, or other real efficient speakers because of the cabinet designs that are required to achieve useable bass response. However, the Omega speakers mentioned above, or the Loth-X bookshelf series will do reasonably well in the bass, for a small sized cabinet that doesn't use a back loaded horn.
