Garage Studio Design

Hi, I am in the process of researching and planning to build a recording studio in 20'X22'x 8.6' garage that is attached to my home and has an existing bonus room over top of it. My background is electrical engineer so forgive if I mistakenly use the wrong construction terminology. I primarily will be recording gospel music so I will be generating 100 dba levels with drums. I do have neighbors relatively close to me (24 ft away) so I do need to achieve STC and TL that are high enough to keep everyone happy. I've attached a sketchup drawing of a initial design (tim's studio design.skp) to be reviewed. Existing construction Floor - 5" concrete slab - don't know if there is any footing underneath North wall(House Side) - finished with insulation and 5/8" sheet rock on 2x4 studs on 16"o.c South wall (Neighbor 24' away) - unfinished with osb mounted to 2x4 studs on 16 o.c. and vinyl siding exterior East wall (Neighbor 100' away) - unfinished with osb mounted to 2x4 studs on 16 o.c. and vinyl siding exterior West wall - Garage Door Ceiling - finished with insulation and 5/8" sheet rock attached to bonus room (?x? floor joist on 16 o.c) I assume it is a 2x6 joist. Will have to verify. Additional details: There is a breaker box 3' 6" above the concrete floor in between studs on the East wall (see attached tim's studio design.skp) An 14" from north wall x 18" from ceiling enclosed air condition ducts run the length of the north wall(see attached north wall detail.skp) As far as budget, I can realistically commit $4000/year to this endeavor. Again thanks in advance for any advice on the studio layout design. If more details are needed please let me know Tim

Here you go - one possibility :) Just a sketchup note for users. Before saving your file go to Window/Model Info/Statistics and hit the purge unused button. It clears the file of any components, materials etc that you no longer use in the file - it can reduce your file size quite a bit sometimes. cheers john