I have a tandem garage (i.e. single width, double length garage) and am about to convert the back half into a guitar/recording studio.
My wife is insisting, rightly so, that it is thouroughly soundproofed and I am looking at using a floating stud partition and walls with rock wool insulation to achieve this. A major expense will be the requirement for two large windows which will need to be sound insulating as the back half of the garage has two single glazed windows currently.
I'm sure it will be great once complete, but would be interested in any tips, experience from others who have done this conversion.
P.S. I won't be doing the work myself, we are getting a new kitchen put in and getting this done at the same time by a reputable joiner.