Over the last 8 months i've been gutting my basement to foundation and rebuilding it as a nice studio that will suit my needs. I spent about a year planning before i did anything. I consulted with accoustic engineers, i read books, i did everything to get a better understanding of accoustics. I also went from a dude who knew very little about construction to someone who framed, wired, insulated, drywalled, painted, floored, and everything inbetween.
The studio is nearly complete. It's functional but i'm still tweaking the acoustic treatment to get what i want out of the rooms. I'll post more pics when i finish all the trim, etc.
I did finish my mixroom quadratic diffusor yesterday though:
It's 4'x8'x1'(deep). When framing the mix room, we left a 6 inch recess so the diffusor only sticks out 6" from the wall.
I thought it would make a subtle difference but it was pretty audible. I wish i had an RTA to test before and after, but i did some listening before we put it in and then after. The stereo imaging and transients at mix position got tighter. According to the calculations, it should diffuse from about 200-2500hz.
This thing was super cheap to make too; i think it cost me about $125-150 in wood. The tricky part was just the planning and setup to build it. It's not perfect, and if i did it again, i would have changed a couple things, but i'm really proud of it.