Soundman2020 - Studio Design Forum

That's ideal, thanks Glenn.

and if you want to go crazy with it - the walmat can be used to lift the soffit framing and decouple it there as well. i often use it for single surface studios where we cannot separate the slabs and want less air -> structure -> structure/floor transfers (mainly in places where people listen to mixes very loud or use 100W guitar amps full on etc...)

Thanks Glenn, that's useful to know.

I cut the sole plate for the soffit structure this morning before a session. First I measured and marked the dimensions onto masking tape on the floor, then cut the stud wood to size. Working out the correct angles to mitre the baffle face corners was a bit of a puzzle, but I got there in the end!

Then I made an exact copy of this for the speaker on the other side. The theory is that if I turn it upside down it will be an exact mirror image.

37° was the best angle I could get the soffit face with the speakers positioned as close together as possible within room constraints. The ideal is around 30°, but I know 37° will work fine as I've been mixing like this for years.
Spacers for the attachment bolts to the rear of the speakers. 18mm OSB + 2 MLV "washers". Once I know everything is properly placed I'll screw these into place so they don't rattle about or roll away when removing the speaker.

I've been busy and really didn't want to rush the process of fixing of the soffit structure sole plate to the floor, so it took a bit to get round to doing it. Had I been able to screw straight down through the plate into the subfloor it would've been easy, but doing this would have ruined the hardwood floor. I want to preserve this in case the room stops being a studio at some point in the future.

I attached the sole plates adjacent to walls by running 100mm screws diagonally through them so they emerged out the bottom of the plate and bit into the floor where (under normal circumstances) skirting board would cover the floor.

Getting an accurate and strong join at the angled corner of the soffit was tricky, and I ended up using tooth plates for this on the top side, then a screw to strengthen the join where the plate did not. It made a very strong joint, and a lethal boomerang.
Pushing these tooth plates into place was some task. I had to do it bit by bit in the vice. Nail plates would have been a better choice. I initially planned to use these on all joins, but the mallet just bounced off them when I tried. Using screws and standard brackets was easy enough though once the angled part and plates next to the walls were in place. I'll probably beef up all those joins when more of the structure is assembled.

one thing to consider: some soft rubber under them to also help keep them in place. also helpful: https://www.wikihow.com/Throw-a-Boomerang

LOL!

That's an excellent idea about the soft rubber, especially as the floor is not 100% level. I will make it so.

Cheers!
Jennifer

Your idea of putting soft rubber under the sole plates was genius Glenn. I cut up some neoprene wraps people use when they have a sore joints, and stuck them on with double sided tape. Now the plate that was on a slightly uneven floor no longer creaks when I stand on it. And we absolutely want to keep these structures as creak free as possible.

Cheers!
Jennifer

might even decouple if a bit

gullfo wrote:Source of the post might even decouple if a bit

There's always the old tennis balls if that doesn't work

The sway braces arrived so I was able to carry on building the soffit structure. The leftmost vertical is the one with the sway brace. I left a small gap between the top of this and the ceiling / rafter so they can move relative to each other if necessary.

I had to make a couple of wedges to bring the surfaces into parallel to attach the sway brace. It looks a bit rough but the join and structure is very stable.
A couple of notes:
- The ceiling and vertical upright can easily flex within the limits of the sway brace. Bigger vertical movements than this would be highly unlikely, but would split the brace apart before transferring a significant load. This is a good thing.
- the brace is designed to oppose horizonal movement in the "wall falling over" direction. It does this superbly.
- Opposition to the "along the wall" horizonal movement is from members in the soffit structure, not the brace.

The rightmost vertical upright didn't need a sway brace as it could be attached to an existing non-load bearing stud wall. I left a small gap at the top just in case.

Cheers!
Jennifer

nice! the WIC product line is very nice esp when used with heavier assemblies i like them more than the Kinetics products in that role.

Cheers Glenn. You can identify the brand and type from these photos - I'm impressed! For the benefit of others, they are WIC-1 Acoustic Braces supplied by Mason UK ltd. To my surprise they were happy to supply small quantities, something to bear in mind for the future as they have other quality products useful in acoustics.

Cheers,
Jennifer

yes Mason Industries is a most excellent company -- with the caveat that they often pricey compared to Kinetics Noise (who is also an excellent company as well).

yes, sadly, as i have modeled many of the isolation products for use in my design work, i can recognise 99.9% of them

Indeed, these clips were certainly not cheap but you can tell they are quality items when you start working with them. Thanks for the reference to Kinetics Noise as well, noted. Cheers! Jennifer