Double gyprock vs acoustic masonary blocks?

Hi, I'm currently planning to build a rehearsal studio here in Perth, WA, and I've been trying to figure out the most cost effective means of isolating the rooms. Our budget would be under ~80 grand for 8 rooms, just for construction, and we're planning to build into a leased industrial unit. However, cost effectiveness is our primary concern. I think floating floors are well out of our financial means, so we're planning to use drum/bass risers to decouple amps & kits from the floor. So my main concern is matching the STC rating of brickwork walls with a gyprock ceiling. Or just sticking to all gyprock construction if it makes sense. The masonary blocks we're thinking of using are here: http://www.midlandbrick.com.au/Docs/Product/BricksBlocks/Product_BricksBlocks_Midland_Bricks_Acoustic_Masonry_Concrete_Blocks.asp?AUD=home&Nodes=&site=Midland I was also wondering about the benefits of a single brick wall, a cavity wall filled with insulation, or perhaps a single layer of brick with a layer of gyprock on resilient channel? And what ceiling construction methods would match these? Do I need an internal ceiling for each room and a physically isolated 2nd ceiling? What if the 2nd ceiling was common to all adjacent rooms? Essentially, I know nothing about bricks and sound! Only gyprock. Cheers! Anthony

Our budget would be under ~80 grand for 8 rooms, just for construction, and we're planning to build into a leased industrial unit.

So the outer leaf already exists? How is it built? What is it made of? (Floor, walls, roof, windows, doors)

I think floating floors are well out of our financial means, so we're planning to use drum/bass risers to decouple amps & kits from the floor.

I'm assuming that this will be on the ground floor of the building, and that the floor is reinforced concrete slab? Will you be occupying the entire building yourself, or will you be sharing it with someone else? In other words, will there be anyone else using part of that same slab, or within the same outer-leaf walls?

So my main concern is matching the STC rating of brickwork walls with a gyprock ceiling.

Actually, STC isn't a good system for measuring isolation for studios. It does not take into account the low frequencies, which is where all the big problems are. So don't rely on STC ratings for designing your isolation.

I was also wondering about the benefits of a single brick wall, a cavity wall filled with insulation, or perhaps a single layer of brick with a layer of gyprock on resilient channel?

What you need is a concept known as "MSM" or sometimes incorrectly "MAM". Search the forum for that to find out about it. It is the most economical way of getting high degrees of isolation for studios. There is no better method at reasonable cost. The basis of MSM is two (and ONLY two: never 3 or 4) leaves of mass, separated by a large air gap which is filled (or partly filled) with insulation. The air gap needs to be at least 4" deep, absolute minimum, and the mass needs to be sufficient for whatever your isolation needs are. There are equations for figuring it all out.

And what ceiling construction methods would match these?

Whatever will get you the same level of isolation! That might mean a larger air gap between the leaves, or more mass on the leaves, or both, but the key is that the level must be the same for the entire structure. It makes no sense to have three walls and a ceiling rated for a TL of 70, but the fourth wall only rated for 50. If you do that, then your entire structure is only TL 50.

Do I need an internal ceiling for each room and a physically isolated 2nd ceiling?

You need two leaves above each room. One of those will be the existing roof of the building, then other will be what you add. Remember: two leaf ONLY. Never three leaf.

What if the 2nd ceiling was common to all adjacent rooms?

Bad idea. You will have flanking between rooms, and low isolation. Each room needs its own fully decoupled ceiling, which rests only on the fully decoupled walls around that room. The ceilings for each room should not touch each other at any point, and neither should the walls.

Essentially, I know nothing about bricks and sound! Only gyprock.

Gyprock is good. So are bricks. So is concrete. Basically anything that is high density and very massive is a good candidate for building a studio. The biggest issue is normally cost: the sound waves really don't care how much you pay for the mass! So you can use sheets of solid gold if you really want to, and that would work great, but it would give you the exact same isolation as the identical mass of steel plate, glass, brick, or drywall. Mass is mass. Get the cheapest stuff you can that will do the job. - Stuart -