Nothing 60cmx60cm can cure a bass hump unless you fit about 30 of them. Acoustics products look good value until you find out how many you actually need. I spent a lot of time reading up on bass traps and the like about 2 years ago. I still have all that data. Small bass traps will only perform broad band absorption. They will improve things if you have enough of them but they won't do much for a primary room mode. For that you need panel absorbers at least 8ft x 2ft and then two in each corner.