So You have a sugestion for a type of wood to be kiln dried. I have a list of potential supliers in Michigan and Canada, but I am a little blind to some of the details you are discussing.
Hello crim, sorry I didn't get right back to you. I have a lot of irons in the fire.
Well, lets sort this out. First to answer your question. Kiln dried Poplar is the material of choice for KNOCKDOWN type applications.However, depending on the final SOUND TRANSMISSION LOSS needs, Plywood, or MDF may suffice as framing.
However, before submiting my solution, I think you need to tell us all about the proposed project. As much as you can tell us. You may only need a less robust solution. But before we go on, let me address this first.
Important to note 99.9 % isolation is not a must. More vocal to be recorded in finished booth than anything else. Sax and other horns second.
99% of what and at what distance and against what?. Let me illustrate.
You "DON"T NEED 99% isolation" to....:
1. isolate a mic recording a flute inside a tent 50 feet from the Shuttle launch
2. keep a horn player from waking your mother in law at 2AM in the morning. She is in the room above the horn player
3. To isolate vibration from a passing train from entering into the studio . The train tracks are 50' away. There are also busses running on schedule on the adjacent street.
4. To keep Horns/drums from bleeding into the vocalist track.
5. To keep sound from the studio from bothering a neighbor who is in an adjacent TOWNHOUSE/APARTMENT.
See what I mean? I can't help you untill you tell us what you are trying to do, EXACTLY. I can tell you this. The simple criteria, "portable", means an increase in expense, skill level, tighter assemby/fabrication tolorance, and understanding the articulation of the chosen materials for results that work.
This means having the means to to precision cut and assemble HEAVY MDF panels/framwork and the room to do so. If you do, let me know. In the meantime, here is a look at a simplified plan section. This is NOT finished and is for illustration only. You could stretch the dimensions to fit. However, I believe this sort of structure STILL requires approval from the Building Inspection Department to erect, as it is HABITABLE space, and confines a space within a habitable space. I could be wrong though. However, there is one thing here that you need to understand. Any time you build something that is within the confines of a habitable space, if built without permits when they are required, your insurance is in jeprody. Second, you DO own this space don't you? Building anything in a rental is potentially a waste of time, if not illegal.
Anyway, here is a basic plan, but is by NO MEANS finished. There are many more drawings to this and many things are NOT shown in this. It is to illustrate THREE concepts. This first concept is a TWO LEAF (MASS AIR MASS)assembly, where one leaf is supported by a frame, and the second leaf is decoupled from the first. The second concept is the second leaf is an INSIDE OUT assembly
In other words, the framing for the second leaf faces the interior of the room. Beteen the leafs is an airgap as large as you want to make it or have room for. In this case, it is 4". What is NOT shown here is the insulation. Hence a "structural" plan section. On the interior, between the framing members is 3" Owens Corning 703(rigid fiberglass) which is NOT shown. This airgap between the leaves recieve typical BATT type fiberglass insullation. I will show this in the next drawing. But not untill you tell us what we need to know in order to suggest a solution which is appropriate.
The third concept is modules. This whole booth is designed to be built in modules. The exterior WALL leaf is 8 modules. The interior leaf is 8 modules. The floor and ceiling are another 8 modules. This is actually based on a typical crate design. However, it is much more complex, once you see everything. Lighting, absorbers, fabrictrax, cable interfaces Ventilation(HVAC?) and the biggie, the door, which may or may not be glass. Glass and the special seal as shown could concievably cost $1500 alone.
You might wanna price ONE sheet of 3/4" MDF in your area too. And the price of KILN DRIED and MACHINED 8quarter Poplar. This does NOT come as 2x4's. It must be cut and surfaced by a shop Hence the suggestion of PLY or MDF framing. Anyway, here is the basic plan section.
fitZ
Thats why HIGH SPL/LOW FREQUENCY isolation cannot be achieved with a "knockdown" solution. Unless you have a forklift to move modules with 4-5 layers of 3/4" MDF. 