I just bought the Roland RD 300SX. Through headphones I noticed some of the lower notes (C2, C#2,D2 and D#2) on Piano 2 giving a funny hammering sound when playing hard. A metallic sound is heard when playing Piano 3 in a few of the middle notes (C4, C#4, D4 and D#4). I just want to know if this is particular to my instrument or if they all do that. In the shop when playing over speakers I did not notice it. It's not a big issue but it is there. Sorry to send this message in English. When it comes to speaking AND reading my German is prettty good. Writing is not very good. So answering in German is OK for me. I joined this forum as I think it's one of the best I have seen !!!!