Music In Iowa? Yup, with a little advice if you please...

[scalpshifter]

Hi Everyone,

This is my first post, but probably not the last….

My story in brief is that I am about to build studio project number 2. I have a decent studio in a leased subterranean location now, but I made a lot of mistakes (despite trying not to) and cut some corners in the construction. On the next pass I want to do a better job and create a great working environment (also I need to move closer to home and a bit further away from the folks who, regrettably, cannot read my giant “please do not knock, closed recording session in progress” sign….).

I am attaching a few photos of the intended space – a shop loosely (in the mechanical coupling sense) attached to my house. The total available area is about 28’ x 30’ but the portion resting on an independent slab of concrete is about 18’6” x 30’ and it is that area I plan to use for the two main rooms (control and one iso/composition/office space). I do not need a lot of rooms for my work – but I will build a separate machine/computer room and a small instrument/gear repair shop. Please note that there is a TORNADO SHELTER between the slab part of the shop and the house (gotta love Iowa) and this creates a mechanical separation of sorts that I plan to exploit. I’ll attach a quick sketch and get a better rendering shortly.

My initial question is with respect to the existing wall and ceiling structures. The studs are covered with sheathing that is a composite of wood fragments compressed together. The ceiling (8’3”) has one layer of gypsum board attached directly to trusses shaped as sketched below.

My intent is to float a wood floor with the second layer of walls resting on it. Then, suspend a multilayer (but 2 leaf, M-A-M) ceiling from the existing ceiling using a commercial isolation product (like RC8 from Auralex or a less costly equivalent – any suggestions welcome).

I want to avoid the “too many leaves” problem and I am looking for advice with respect to the strategy of finishing (covering) only one side of the NEW walls with a sound isolation layer to create a surface, behind which is an air space, followed by the existing sheathing. The problem is that on the other side of the sheathing covered studs is the outside of the building covered with cedar siding – another surface.

I read through the thread discussing multiple leaves that are inevitable whenever you have multiple door sound locks and rooms within rooms and it did not seem to reach a solid conclusion other than that the problem diminishes as a function of the air space distance between leaves.

Question: Is my plan flawed and if so, what suggestions does anyone have?

Next, with the floated floor and dropped ceiling I will lose a significant amount of headroom – plus I plan to put a slanted reflective surface at the front of the room that is inclined at least 10 degrees to avoid the immediate reflections from soffit mounted speakers. The room will only be 6 feet tall at the very front and have maximum height of about 7’3” to 7’6” depending on how I go about constructing the floor and ceiling structures.

Question: Am I going to regret this vertical squeeze and can it be improved/compensated?

BTW, the attic above the space contains a heater that will be moved to the tornado shelter due to its incredible noise level. The attic is otherwise open and can be manipulated/insulated but I do not want (i.e., cannot afford) radical alterations of the truss/roof structure.

Question: Anything clever I can do here? Hanging bass traps for example?

Thanks in advance for any advice, URLs to explore, anything else!

I’ll keep future posts short and few.

Eric

[John Sayers]

Question: Is my plan flawed and if so, what suggestions does anyone have?

No it's not flawed - it's correct. You can gain some headroom by making your floating floor on 2 x 2 instead of 4 x 2 - or by laying the 4 x 2 on their sides so it's a 2" height.

With the resultant low ceiling I'd wipe it out with a layer of 3" 703 and add slots or Ethan's panels to the walls to keep the highs moving in the room.

cheers
john

[scalpshifter]

With the resultant low ceiling I'd wipe it out with a layer of 3" 703 and add slots or Ethan's panels to the walls to keep the highs moving in the room.

Wow - that was fast - thanks.

Would you recommend ignoring addition of an incline in the ceiling in view of the absorptive layer (since there is nothing reflecting from that surface anyway)?

Thanks again,

Eric

[knightfly]

Eric, you don't have enough headroom to consider sloping ceilings - so John's suggestion of the absorbed flat ceiling is probably the best you can do.

Your walls; yes, they will be triple leaf. The one on the left especially; your outer siding, even if it's only tin, will degrade isolation somewhat. Eric Desart is probably the only member here who might be able to tell you how much; it isn't a simple calculation at all.

If there's a way you can use the removed material on the inside of your outer studs and edge glue it between your outer studs, this would increase the mass of the outer leaf and help you. Then, your inner frame with paneling on ONE side will finish the m-a-m equation.

The tornado shelter side won't be as bad, but still would be a triple leaf; you can help that some by using 1 or 2 more layers of paneling on your new walls than you intended, but carrying that leaf over into the ceiling area will be difficult.

Do you have an idea of the amount of isolation you actually NEED? It's always best to figure this out before arbitrarily building more or less than required.

Also, if you use a narrower air gap for a floated floor you should consider using concrete instead of wood for the floated slab; it will lower the m-a-m resonance there to a range that will do more for your isolation. Something more like 2" epdm blocks, 3/4" OSB, 6 mil poly and at least 2" of concrete will work better than using flat-laid 2x4's and wood. In either case, a snug fill with rockwool is needed to damp the floor... Steve