YAMAHA X-BACK POST 2013/12/25 　　 　 　Some Yamaha upright models use X-shaped back posts for 　their soundboard. This X-back post is in integral structure, 　strengthening 2.5 times stronger against twists caused 　by string tensions. This leads to stabilizing the soundboard 　and the sound itself. It is said that Yamaha studied 　this structure from Grotrian Piano Company, 　who called it the "Singing board." 　Yamaha stopped manufacturing pianos with X-back posts today, 　largely because of their high manufacturing costs. 　Thus, the pianos with X-back posts can be purchased only as 　"used pianos." Pianos with this structure are scarce, 　with its popularity recently rising in Japan as well as overseas. 　As they are Yamaha's premium models, they are not in affordable price ranges. 　However, certainly it would be eye-catching product with extra 　values & characteristics for your store.