my new studio layout design. please advice me ..

hi all respected n beloved , i m going to build my new studio in 3rd floor area which is 64ft (long) and 17.4 (wide) with outer dimensions/end of R.C.C. post/ pillars. in a part ,width may increases up to 19.4ft with some r.c.c. post's outer dimensions/end in the construction area of the studio which you can see in my sketch. the height is 11ft. i have given all details and measurements below with attachment as much as i can .pls help me with your valuable ideas and advices that i can improve my studio layout to a perfect and ultimate point of success. is there any mistake in my control room placement and control room layout design ? control room side walls are splayed at 6 degree angle each side (both side total is 12 degree ) is there a average width calculations for splayed walls of control room side walls ? what would be the width against 11ft height and 25.33ft length as per Sepmeyer's 1: 1.6 : 2.33 (H:W:L) . is there may be some alterations and enlargement in the studio 'live' room(B) area for achieving better live sound for drums and acoustic guitar etc. i can enlarge the width up to 19.4 feest as outer dimensions of studio room . i am thinking to extend the concrete floor upto 3ft partially to get the passage toward control room ,if necessary. and i have mentioned the area to be extend as "corridor way to CR(expandable)" in my sketch .i can compromise with the Rehearsal room area partially or completely to get a larger and better studio room . then i will shift Rehearsal room to 2nd floor(its available only for Rehearsal room ). suggest me the particular areas for double acoustic door of studio and control room . one important thing i want to ask you is about the actual dimensions of a control room or studio room ,according to Sepmeyer's 1: 1.6 : 2.33 ratio or any other applicable golden ratios. whether it should be fit with outer dimension or inner dimension after completing acoustic treatment ? main purpose to build this studio is recording music like pop,folk,rock and modern songs. I would like to hear my recorded music from my studio monitors up to 120db. all neighbors surrounding nearby by my house are at ground floor level.plz point out my mistakes and suggest me with your better tips and instructions for my new studio . plz accept my heartiest thanks and love to you all in advance .