Dog + Bear Studio build

[BriHar]

Kind of gives you an indication that a fair amount of sound was in fact leaking through the walls beforehand.

Like your work up to now

[stevev]

cheers Brian and thanks for checking out the build

I'm actually quite amazed at the difference the rendering has made now it's 100% done. There must have been quite a serious amount of air passing through that brick-work. I didn't think it would be such an audible difference, but the sound internally has gone from a bit echoey to 'full blown reverb chamber'

....and another tip of the hat to Stuart for the advice on that amongst other things.

[BriHar]

And now that you're imprisoning all this acoustic energy, you're going to have to deal with it - can be quite sobering.
But such experiences as the one you've had are great because it gives you near tangible evidence of what your dealing with as opposed to just following abstract ideas and procedures.
What I mean is, people tell you to do this and that and you're never really sure if this is really having any impact or is just part of the dogma of studio building, but now you have personal experience which helps you apprehend the significance of what you're doing.

[stevev]

What I mean is, people tell you to do this and that and you're never really sure if this is really having any impact or is just part of the dogma of studio building, but now you have personal experience which helps you apprehend the significance of what you're doing.

well said Brian. It's a nice 'milestone' to reach in the build where the acoustic properties of the room are tangibly starting to come into play. Up till now it's just been a REALLY expensive shed

[stevev]

live room wall idea.jpg

here's an idea of what i was thinking of for the live room. Alternating inside-out and normal panels. The ceiling would be completely soft (75mm-90mm polyester insulation with cloth cover), and the floor is concrete.

I figure the panels that are on the inside of the room would retain some top end, and the cavity's could be made helmholtz resonators, or just insulation with cloth cover if necessary. Resonators and bass traps would be floor to ceiling.

In my original floor plan there's a booth in the live room, but I'm thinking of losing it as I'm getting a better sense of the space and would rather have more room in there. Floor area for the live room is about 25sq/m.

[BriHar]

I like the idea of integrating the flexibility for alternating treatments in the walls, but I wouldn't bother alternating the inside-out and normal panel construction - just makes the construction more complicated. Using inside-out for the entire wall construction will give maximum flexibility. If you want to have a few more reflective sections, then you are free to panel that section with anything from metal to plywood, vinyl to homosote, as you see fit to exactly tailor the treatment at that spot to your wish (you could even incorporate panel traps or limp membrane traps). The same fabric would cover it all if desired so the differing treatments are hardly visible.

I notice you have no cross members planned between your studs (forget what they are properly called), I assume they will be added.

[stevev]

If you want to have a few more reflective sections, then you are free to panel that section with anything from metal to plywood, vinyl to homosote, as you see fit to exactly tailor the treatment at that spot to your wish

yep, that's a solid point there Brian. I was thinking it would make the construction more difficult as well. In your experience of inside-out construction, does having just a plain cloth cover over an empty 'inside-out' stud cavity reduce the top end at all?

and yep, there are 'noggins' (cross-members) in all the walls. I was drawing more for speed rather than accuracy to get the idea across:)

[stevev]

internal wall start.jpg

here's the beggining of the live room construction. It's a good feeling to be finally getting some of the actual room built, but this is where work has to stop for a bit, as my main landscaping/earthmoving buisness needs me back on the tools. (not to mention going on a sneaky fishing trip )

I'm going full inside-out constuction and as Brian pointed out, it'll give the most flexibility for the room. So ignore that half-half pic a few posts back

has anyone got any ideas on lifting these sections of wall in to place? two blokes could probably do it but I wonder if anyone has any smarter ideas than just using pure grunt to get them vertical.

[BriHar]

In my own build, I filled every cavity with rockwool, some I gave an extra top layer of 18mm rigid fiberglass a couple have a 10mm homosote panel facing (this was more to provide a pinboard function) and particularly cavities (and the cloud) in the ceiling have a layer of plastic foil. I was concerned that the highs would be sucked out too early; the plastic foil treatments coupled with the slat walls left and right have this well under control.
I wouldn't think an empty cavity would be such a good idea as this could encourage resonation or a bass buildup at that point. My studio is a bit more critical as it is quite small so I went for total absorption using facings (or not) of different materials for control. It seems to have paid off, and mixes translate exceptionally well.

As for raising the walls, Brute force is really all you have at your disposal unfortunately. Stuart once introduced me to wall jacks, but they really aren't practical in a confined space. In my own situation I had not even enough room to get 2 or 3 people in a position where they could even hope to lift a wall section, so I built my wall sections in the upright position braced against toppling, then moved them into place with a car jack (on wheels) while my son ensured they didn't tip. Went fast and easy.

[stevev]

I've asked a few builder and carpenter friends who say the same thing as you Brian. Either lift the walls with a few people, or prop them up vertical and manuver them in to place when they're done. I like the idea of the car jack on wheels, and probably the easiest option if there's only two people.

The other option is to use a duct lifter, but they're reasonably expensive to buy and hiring one wouldn't be cost effective for the amount of time I would need it.

[stevev]

a calibrated galaxy cm 140 arrived today and i've done some testing. all 'C' weighted slow.

60hz sine - 115db inside, 66db outside, 63db above the roof and 71db at the door.
averaging 48db TL.

70hz sine - 115db inside, 63db outside, 60db above the roof and 63db at the door.
avg 53db TL.

80hz sine - 118db inside, 68db outside, 68db above the roof and 69db at the door.
avg 49db TL.

90hz sine - 120db inside, 65db outside, 80db above the roof and 68db at the door.
avg 49db TL.

Drum track - 115db-118db inside, 64db outside, 67db above the roof and 68db at the door.
avg 48db TL.

Now I'm no acoustician, and all these measurments will invariably have real-world errors in them, but what i'm getting from those figures is this: Two sheets of 16mm gyprock, on resilient mounts, with green glue, gives around the same TL as a rendered brick wall. I'd have to say this is reasonably correct as the level difference i was hearing between outside and above the building matches the figures. The 90hz sine was audibly louder above the roof and perhaps the roof cavity is resonating at this frequency.

The door construction and seals are performing nearly as well as the walls.

With an overall average of 49-50db TL for the building at the moment, I'd be hoping to get over 60 and possibly to 65 once the internal walls and ceilings (2 layers 16mm with an insulated 150mm cavity) are built. 65db being the target so I can have a drummer hammering away and not be annoying the neighbours

So i'm feeeling good about the results vs the time and $'s that have gone in so far. Now its time to go fishing for a few days

[BriHar]

Just for clarification, The frames were indeed built laid down on the floor, then raised up to position. As each section was completed, it was moved about a meter from the wall and braced. Then the plasterboard was added. Finally blocks were firmly screwed to a couple of studs to facilitate lifting with the jack, and then lifted an inch or so and moved slowly first at one end then the other, back and forth between ends the section was "walked" into place. The two layers of fermacel on the frame was calculated to weigh nearly a quarter ton!

If it helps here is a link to my project. http://www.johnlsayers.com/phpBB2/viewt ... 5&start=60

[stevev]

Cheers Brian, I appreciate the run-down on the wall construction and the link. I think i'll end up doing something similar with my walls, as the wall-jacks that Stuart suggested look too big for the room i'm working in, which I think, is the same problem you had.

I've made the 30th dec a firm date for completion. I think that's enough time, but........

[John Sayers]

One of my clients used a system where he laid down the bottom plate on rubber and attached to the floor in place - he then lifted the wall frames directly onto the bottom plates.

cheers
john

[BriHar]

That sounds like a very rational and practical construction technique. I don't see how it would facilitate raising the framing section in fact I should think it would make it a touch more complicated due to the extra height of the sole plate, but definitely do-able.