What floor is this space on, or what is the structural make-up of the floor? The reason that this is important is because the most economical way to achieve a high STC value is with concrete block walls. (F.Alton Everest, Sound Studio Construction on a Budget, pg 181). If this room is a slab on grade, or some other floor system that can support a masonry block wall, that is probably the fastest, cheapest way to achieve an impressive STC rating for the wall. You will probably need an engineer to determine if your floor can support this type of load. According to Everest, if you can support the load, and can spare the space required, two concrete block walls with an air space between them will provide an STC rating that is almost unobtainable with typical frame construction. But even a single block wall, with a drywall partition a few inches in front of it, will provide a very high level of transmission loss.
So, if you can make it work, masonry block wall is the winning answer. If masonry is not feasible, you will have to utilize some combination of mulitple drywall partitions and air cavities, along with insulation. But don't just randomly start throwing up drywall - there is some serious science behind all of this and you need to know when an extra layer of drywall is appropriate and when simple air space is called for.

Steve
sjp@pacbell.net

How about cinder block? Does it soundproof well? i was thinking about making a cinder block wall filled with polyfoam or somthing.

I'm not sure if its the most effective for soundproofing but I worked on a construction site a couple years ago and we filled cinder block with cement, and it was a very easy thing to do. That would probably be a lot easier to do then try and build cement walls. If you can find someone that has a little expierence laying brick and get a couple of your friends it wouldn't take more than a day to build the wall.

easier yet....just fill em with sand. Dbl up tha walls. One wall of cinder filled with sand then add 2-3 inch airgap and build a second cinder block wall filled with sand.

The hard part isnt the wall, the hard part is the window, if you want one :)

oops forgot to mention, if you can cut your slabs around the perimiter of the rooms you could do even better. Just make a slice with a wetsaw and fill the gap with some felt.

great idea, but how would i secure the sand in the blocks? (dumb question?)

Gravity! take care Logan

I assume you would actually *build* a wall with cinder and morter, in which case I would start with the first layer and fill with sand then move up to second layer so on and so on.

Originally posted by scenaria:
easier yet....just fill em with sand. Dbl up tha walls. One wall of cinder filled with sand then add 2-3 inch airgap and build a second cinder block wall filled with sand.

We've used this method quite often on some new construction, as well as every place we've worked on in the Caribbean. Cinder blocks reinforced with 'rebar' filled with cement

As for the 'airgap', good idea...but that's the "outer shell" of the room that wants to be filled cinder block, not the 'inner shell'.

After the 2-3" airgap, you float the 'inner shell' floor on the 'outer shell slab' [usually using Neoprene], then build a very solid floor [like 2x 6 stud with bays of unequal volume, sand filled], 3/4" baltic birch plywood above and below the studs, and some additional drywall sandwiched between two layers of plywood for the 'control room subfloor' [where you put the 'finish treatment' so the floor looks and works well inside the room]. Oh, BTW, don't forget to lay out your wire troughs right about now, or you're going to be one bummed out son of a bitch in like a month or two.

Then build your 'inner shell' walls on the floated floor. That way you're not allowing the 'outer shell floor' the ability to transmit sounds as you would if you were using the 'outer shell floor' as a common floor.

You float the 'inner shell ceiling' on the 'inner shell walls' and you're in OK shape. All of these walls want to be airtight, which is the same as 'watertight', which doesn't lead to a healthy environment unless you get your HVAC straight...which is a whole other nightmare as even when you're using separate 'heat exchange units' you still have a several "shell piercings" with which to contend.

You also have to be very conscious of the rate of airflow so you don't hear the sound of the air moving through the ducts, which means you have to move a great volume of air, very slowly. I generally like to have the 'returns's over the desk [so when you have smokers working there, the smoke gets lifted out straight away, also the heat rising from the desk is immediately vented out of the room], and the 'supply's in the back of the room but be careful that they don't blow on the mix position, ...I hate getting a stiff neck from the HVAC system blowing on me all day.

This really isn't a sport that should be played by amateurs. If you're serious about wanting to build a good room, read all of the books , then hire a good 'control room designer' to at least go over your plans.

I'd recommend someone like Chris Pelonis on the West Coast; Bob Alach, Frank Comentale or Fran Manzella on the East Coast. If you have some money, George Augsburger is one of my more favorite designers, but from the work of his that I've seen (and worked in), if you open your mouth he'll listen to you...which have led to some of his rooms sounding like shit. From what I've seen of his work, if you just let him do his thing, it comes out great.

If you're related to Bill Gates...check out Tom Hidley. His work is phenomenal!! Most of the rest of the 'famous designers', from "Bau Ton" to "Walters/Storyk" ,
"Harris/Grant"...suck. Their shit looks great, it just very rarely works worth a damn, at least that's what I've seen of it...

Best of luck.