The models are now so common that I have chosen to include them in appendix A, together with the rest of the standard pan models. These bass models are commonly used extensions of the ordinary nine bass. The advantage of the extended tonal range doesn't seem to be enough to get them to catch on, though. The 27-note range of the nine bass is usually considered to be sufficient, and it doesn't seem possible to reach much lower in musical pitch by using more drums. The most common exception from the standard drum is a small drum, used for kiddies' pans and tourist pans.
Some drums have a diameter that is bigger than the ordinary drum.
These tenors cover a range that is almost equal to a double tenor and have a pleasant tone. Due to the difficulty in finding these big drums the idea of making pans from over-sized drums will presumably have hard to catch on. But to the experimenting panmaker, the differently styled pans show that it is possible to make pans with other sizes than the standard one. It may well happen that the drums will be shaped and sized in a way that is more directly adapted to the acoustical needs of the pan, maybe bigger and in another shape rather than round. The Rocket pan is a fancy, experimental pan, used by the Desperadoes Steelband.