They are cheap Comparison of Bass traps - they should work - DIY is still the cheapest option.
Remember you need A LOT to make any difference ( I have four or 16 feet of the biggest corner traps that GIK sell => Tritraps - to me four is a bare minimum)
Remember you need A LOT to make any difference ( I have four or 16 feet of the biggest corner traps that GIK sell => Tritraps - to me four is a bare minimum)