t.akustik Collector

They're great for what they are: cheap high frequency absorbers. They help reduce flutter eco, but these kinds of foam panels do nothing for low mids or bass, where you actually need absorbtion to reduce standing waves. Covering all walls and the ceiling with foam leaves the most problematic frequencies unaffected, resulting in strange acoustics in your room.

I'd only recommend these for surfaces where you can't (be bothered to) drill holes for installing proper fibreglass/stone wool or thick felt absorbers. Otherwise, save your money and get Hofa's cushions, Clearsonic's fibreglass panels or EQ Acoustics' felt absorbers.