Hello, I think that there are two reasons. Of course there are some special rubbers for pro players and many are using boosters. But of course pro players like Timo Boll or Ricardo Walther have a fast acceleration (forearm, wrist) and the sound in the moment of the racket-ball-contact is much louder.
I think it is ok if we reply in german language? Nearly everybody can read and speak english, so you can write in english and if german replies you can easily translate with google translation.
Hallo, ich denke das hat zwei Gründe. Natürlich gibt es spezielle Beläge für Profispieler und viele Profis verwenden Tuner. Aber natürlich haben Profispieler wie Timo Boll und Ricardo Walther eine schnelle Beschleunigung (Unterarm, Handgelenk) und der Sound im Moment des Schläger-Ballkontakts ist viel lauter.