garden room -> home practice studio build | John Sayers’ Recording Studio Design Forum archive

Hi all. I've been reading this forum (and books!) for well over a year now trying to learn what I can before I try and convert a small garden room into a home practice studio. It's a great resource and thanks for all the great advice I've read so far. I think I've got most things planned out now but had a couple of questions I was hoping for help with. Existing structure: 4.6m x 3.4m x 2m (height) free standing garden room. It appears to be well finished with existing power (with it's own consumer unit), insulated plasterboard walls, external wooden cladding, and double glazed pvc doors and window. It's currently got a laminate floor above chipboard and I assume floor joists. It was here when I bought the house (and I'm not a builder!) which is why I'm not certain of it's construction. Proposed: I'm planning on building a room within a room with the basic wall structure going: Existing wall New stud frame Genie clips + RC 2 layers 15mm acoustic plaster board sandwiched with green glue Auralex acoustic treatment and/or diy bass traps etc I planned to do similar with the ceiling and take up the laminate floor put down some form of DB Board or acoustic barrier mat, put the laminate floor back on and try and find a large rug for as much of the room as possible. For the window I was going to put in a new (additional) pre fabbed sliding window (thick acoustic glass) and build a heavy duty door. I'm going to try do most of the work myself to try and keep the costs down although assume I will need an electrician and plasterer at some point. I'm aware that perfect sound proofing isn't on the cards but hope that I'll be able to keep the noise down enough so that I can use it without having too many problems with the neighbours. It's a built up residential area with the closest other house about 8 meters away. Although I will have a recording setup in there it will mainly be used as a jam room so I'm not too worried about getting the perfect recording acoustics and more worried about keeping the noise down for the neighbours. I was planning on having an acoustic drum kit in there but if I can't get the sound levels down enough I could maybe get an electric kit. I'm mainly a guitarist so most of the time I'd probably be using it with 1 or 2 guitarists and/or a drummer but I could probably wrangle a bass player at times. I'd love any tips or advice on the above but my initial (and early build) issues are: 1) The use of neoprene or other rubber. I've seen that some people suggest backing the timber studs with neoprene to aid isolation of the new walls. I've also seen someone (probably on this forum!) say it's not necessary if I am using genie clips as they provide the isolation and adding 'extra' is unnecessary. That makes sense but I wanted to check as it seems fairly fundamental and it's obviously not something I'm going to be able to change later. If it is worth using rubber would I need to back all the studs where they contact the existing walls and ceiling and can you get away with using a cheaper material than neoprene? 2) My current thinking is to put floor boxes in 2 or 3 of the room corners to avoid making holes in the new wall structure. I'm not sure of the best routing for the cables to try and keep interference and hum down. I'm happy to get an electrician in to do the work but I wasn't sure how familiar with studio wiring a random electrician would be so I wanted to have as much as I could worked out in advance. It seems the simplest thing would be to run the electrical wiring under the floor (especially if I use floor boxes for power) but some of the advice suggests running the power cables around the top of the room and dropping them down the walls where they are needed. This would obviously keep the floor, where most of the audio leads would be, clear of power cables but it's such a small room anyway I'm not sure if it's needed. I think the existing spur is 40A, and is already split into 2 rings for the lighting and power sockets. I'm planning on using led lighting and was going to ask the electrician to remove (or just disconnect) the existing cabling and replace it with new shielded cable. I've tried to learn what I can but any advice would be great or is this all stuff any electrician will know? I hope I've provided useful info and would be very grateful of any advice. I'll happily answer any questions or add some pics if you think that would help. I've also got quite a lot of CAD work done but thought this was enough info for now! Thanks in advance, Ben