low frequency issue

Hi everyone, First, let me introduce my situation : I'm a french student who works on a project dealing with acoustics in water infrastructures. I thus have to compare 2 solutions that could provide to reduce the RT60 in these infrastructures. However, I tested these 2 solutions (stretched...

Hi guys, I have been working on room mode for some time, my room is about 6m x 4m x 2.4m, and having first problematic mode at ~52hz, ~60z and ~90hz, and I almost tired every passive method, eg. >4in absorbent on wall, membrane type bass trap on wall, corner bass trap, but do not really help me...