A fairly thorough sound analysis before and after application of the London 12 showed that it was very effective for mid/high range noise and reflections. Although the kit comes with several broad band panels which are ostensibly there to control low frequency reverberations and standing waves, I found that 100Hz and lower were still way too prominent in my mixes. Part of this is just the simple reality that my monitoring room is smaller than ideal. There are many much lower costing DIY solutions for similar results, but I'm not inclined to take on a DIY project that I'm likely only to need once. I don't feel I have the adequate skill to get the result I want. These are very easy to install and will also be easy to take down and re-install should the need arise. I ended up purchasing some mega traps from realtraps to help tame the low end and there was noticeable improvement. I'm not unhappy with the overall result, but I do think they over emphasize the effectiveness for low frequencies.