Not (very) hard
These mallets are of good quality for the price, if you are okay with shorter shafts, but there are some things to be noted. First off: these mallets are simply not very hard. One will really have trouble getting a decent sound out of higher octaves with these mallets. I have tried various Thomann mallets of the MM20 series, and the soft mallets don't really differ in a significant way from the harder ones. This is not the case with their MM10 series, which offers way more variation. Another notable thing about these mallets is that they seem to have a unintentional multi-timbral thing going on. The yarn wrapping is kind of soft, but the inside is a bit harder, which means the sound gets way more bright when you hit the bars harder.