I see one fundamental error in a lot of studios that people send me. They have foam in their room. Now, what's the matter with foam in the room you may say. I love it. It looks really cool. But the problem is, when you're trying to listen to things, you need to be absorbing all of the frequencies, not just the high frequencies, which is what this does.
If you listen to the way that I'm speaking now, when I talk through it, you'll hear that it takes away just the top end of the frequencies. But all the low end frequencies, they're still bouncing around the room. Anything down for about 8k. So, what you need to do is get some panels that have got rockwool in. Now, rockwool will take away a lot of the frequencies. The really low frequencies, you're going to need a lot of rockwool.
But if you listen the way that I'm talking here, you can hear it's taken away most of the frequencies apart from the very low frequencies. So, that's why you need rockwool panels that have got this stuff inside rather than cheap looking foam on your wall that’s literally doing nothing to the sound apart from taking off the top end. And that’s no good I you want to make good music.