John Sayers' Recording Studio Design Forum Archive

I have a question regarding my live room. The room is a rectangle with one of it's long sides splayed, the floor is concrete, the walls are drywall, and the ceiling is standard commercial acoustic tile. The leaf spring leaf method was used (2 sets of framing and 2 layers of drywall for each leaf) to seperate live room from control room.

Can you suggest a particular type of wood or woodflooring brand that is commonly used in the live room scenario? And, is there a particular thread or link that has info on the construction methods for installing sub floors and hardwood floors?

Becuase all four walls of this live room are already constructed and can not be floated, is it still worth it to float the floor on rubber?

And lastly, I have seen floor tiles (aprox. 8" by 24" with 1/4 " and 1/2" thicknesses) made out of fiber board(partical board similar to mdf)...Is this type of material more reflective than hardwood? And does it sound OK?

Thanks
James

I also thought I should mention that above the ceiling tiles and insulation is a corrugated steal ceiling (above the steal is concrete). Typical construction for comercial buildings.

thanks
James

James, is the amount of isolation between outside world and studio enough as is? What about between CR and live room?

The short answer is, floating the floor will improve isolation mainly due to flanking through the concrete - it will also help by isolating floor vibrations from your walls (still flanking, but a different path)

Let me know if your present isolation is OK, or if you need more (and approximately how much more) and I'll try to help... Steve

Hey Knightfly,

Isolation from the outside world is pretty good. It's a concrete commercial building and it's set back from the street. Although it is located on a busy downtown street, and there is a street car (train). My unit is in the basement, so street level is approx. my ceiling. At the moment the ceiling is entirely open...When I'm finished with the floor I am planning on building a ceiling out of steel studs and acoustic tile and hanging it from the existing steel/concrete ceiling with hangers (resilient chanel I guess). And I'm planning on putting at least two layers of insulation in this ceiling.

Presently, inside the unit, I can hear the street car and the occasional low rumble from trucks. So anything I can do to improve isolation at this point is definatly worth it to me. Most likely I will be faced with trying to cut out low rumble of train and trucks with eq once I start recording.

I'm not sure about Isolation between live room and control just yet becuase only the base drywall layer and taping is done so far. But due to the fact that neither side of my double wall is floated there will definatly be isolation problems here as well. I'm prepared to live with the bleed between rooms but just need to do everything I can to get as much possible isolation out of this space.

It is pretty hard to answer how much more isolation I need...do you think it would be worth it to record the street car from inside the unit and find out which freq's are coming through and at what levels?

Yeah, that would be a worthwhile thing - that way, we can design your isolation walls for best transmission loss where it's needed most - check out the thread here

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=1683

might give you some ideas for methods, etc... Steve

Thanks Knightfly. Great thread.

Do you know of any others that deal with control room ceiling design. I need to know things like how steep should it be splayed, and how to calculate the optimal mix position based on where the least amount of ceiling early refections will be.

I do this for each room using an old DOS-based Cad program (I'm used to it, kinda like an old comfortable (but stinky) pair of slippers...

I've worked out a "polish ray-tracing" method to adjust angles to where they either travel a minimum of 20-25 feet before returning to the mix position, or they get absorbed (smaller rooms) or diffused (larger ones)

I tried to explain this on another thread, I think it was in the Design forum - try a search on the word TRACING (only capitals for emphasis)

Nevermind, it's here -

http://www.johnlsayers.com/phpBB2/viewt ... c&start=60

This method requires a fairly heavy duty drawing program; paint won't cut it, not sure about Smart draw. An actual CAD program may be necessary; I've got two of the cheaper ones loaded on my laptop but have yet to find time to play with them to see if they work. Last I looked no one could tell me for sure if Autocad can do this, haven't checked that yet either. I guess if you get desperate, you could get a compass, protractor and engineering tablet and draw the angles as I explained them... Steve

Hey Knightfly,

I just read through your explanation on the ray tracing method for calculating early reflections...very cool stuff.

But now I'm questioning if there is any benefit to using an angled ceiling in a control room if the ceiling is fairly non-reflective. The material I have to work with is standard comercial acoustic ceiling tile. And I'll place a couple layers of insulation on top. Above that there will be an air space of aprox. 12" to 18" , and above the air space is a corrugated steel ceiling with poured concrete.

Anyway, does acoustic tile have any reflective properties or is it just absorptive? Is there any benefit to angling a ceiling like this?

Thanks
James

So-called "acoustic" panels typically have around 0.5 absorption coefficient in the midrange, so yes they will reflect a fair amount - so at least around the actual mix position an acoustic ceiling would benefit from splaying.

To get around this people use clouds of rigid fiberglass, otherwise splaying needs to be over 6 degrees just to combat flutter echoes - for actual RFZ characteristics, the way I described is necessary and will result in steeper angles. Headroom limitations when not building a studio from scratch often mean using absorbent when ceilings aren't high enough for the required angles... Steve