which room should i choose?

I am currently moving into a house i am renting. I plan on using one of three rooms in it as a mixing studio (i.e. control room only). The dimensions of the three rooms are as follows: 1) 13'4" X 13'4" 2) 12'8" X 13' 3) 18' X 12' the ceilings in each are about 9" tall. i am wondering which room would be best suited for mixing/purposes? do any create special problems/concerns? my next question is regarding acoustic treatment. the house is very isolated from outside noise (it is a house made of stone in the country). of course, the rooms themselves need some control. As I cannot build permanent walls or anything in the house (i am only renting it), i need to craft something that is easily removable. i have plenty of access to building materials as well as a skilled carpenter/cabinetmaker. I was thinking of building some helmholz resonators and diffusors for the room, as well as hanging some theatre-type curtains in various places. I understand that the helmholz resonators can be built frequency specific as well as broadband (not really sure how to choose what to do hear). Am i on the right track with my ideas? Any of you gurus have any ideas? thank you, joe schacher p.s. i have just discovered this site, and i am amazed at the community you have going here. this is great!

Greetings and welcome! I personally would pick the 18'x12' room because it's the farthest out-of-square. The other two rooms, with lengths close to the same distance as their widths, will reinforce the same room modes. Obviously the bigger room will have modes to deal with, but it'll be a little easier. BTW I hope you meant the ceilings were 9 feet instead of 9 inches. ;) Anyway, John's wall units page will show you how to build all the treatment you need.

yeah, 9 inches! :) where would i find the page you referred to? thanks!

on this page..=).. www.johnlsayers.com