Bass Corner Absorber / PUR-Foam

Hi, just a short question, becauses my English is toooo bad ;-) Iam searching for Bass Corner Absorbers and I found a company, which sells PUR-Foam materials, but not especially for accoustic purpose (so there is no special information about). In order to foam you find always two values, roomweight (Raumgewicht) and "pressurehardness" (no idea about the English word, in German it is Stauchhärte). There are three different kinds of PUR-Foam: 1. RG 28 - SH 3 2. RG 35 - SH 5 3. RG 40 - SH 7 The question is, what material is the best for accoutics ? Higher values are better or do they have worse propperties ? Any idea ? Thanks in advance. The_Unknown

Different foams have differing acoustic properties same as rockwool, mineral wool, etc - I don't speak enough German to help with using non-acoustic materials properly though; maybe some of our multi-linqual members can help? Guys?? Bitte?