New dream house with studio and workshop.

[Wheresthedug]

Thanks For the detailed response Starlight. I don’t have the Marshalls book but I have read Rod Gervais book from cover to cover a few times, plus Philip Newel’s book, and made some progress on Everest’s Master Handbook of Acoustics. I understand the basic principles but my maths isn’t great when it comes to testing the actual formulae.

I will be building a decoupled room within a room and filling the airgap with insulation. The problem I am grappling with (through my lack of a detailed understanding) is how the windows perform in this system. The full system is only as good as its weakest link and it appears that the windows will be the weakest link. They also can’t have the airgap filled with insulation (or they cease to function as windows and you’ve seen the views ).

I have always understood from Rod, Stuart and others that two leaf systems are your friend but three (or more) leaf systems are the work of the devil and should be avoided at ALL costs. However, on of the examples in the Newel book details a quadruple glazed window system. I can’t get my head round how that works.

Hopefully the Jedi master of acoustics (aka Stuart) will be able to provide some enlightenment.

In truth, I am intending to commission Stuart to do the actual studio design but as this stage I just want to get the building wind and watertight without wasting money right at the beginning of the project.

[endorka]

Source of the postYou can see that the middle section, for frequencies between 22 and 367Hz, are lower than just the single leaf wall, which surely cannot be correct. I need someone's help!

I suspect that's the mass-air-mass resonance. Presumably the idea is to get it significantly lower than the lowest frequency you'd like to isolate from. Adding mass to the inner leaf would do it, as would increasing the depth of the cavity.

Cheers!
Jennifer

[ericwisgikl]

Starlight, the error seems to be here:

Source of the post R = (R1 + R2)/2 + 20log(f * d) - 29 ...[for the region where f0 < f < f1]
R = (52 + 34)/2 + 20log(32 * 0.15) - 29 = 43+20log6.45-29 = 28dB @ 32Hz
R = (52 + 34)/2 + 20log(63 * 0.15) - 29 = 43+20log9.45-29 = 34dB @ 63Hz
R = (52 + 34)/2 + 20log(125 * 0.15) - 29 = 43+20log18.75-29 = 39dB @ 125Hz
R = (52 + 34)/2 + 20log(250 * 0.15) - 29 = 43+20log37.5-29 = 45dB @ 250Hz

I have a spreadsheet calculator, where everything else is the same, but not this formula. In my calculator it is
R = R1 + R2 + 20log(f * d) - 29

I'm not sure which is the correct one, but mine seems to be more accurate, since results are:
70.6dB @ 32Hz
76.5dB @ 63Hz
82.5dB @ 125Hz
88.5dB @ 250Hz


Best regards,

Eric

[Starlight]

Well done, Eric, you found it. And what impressive results they are, but a 215mm wall is no ordinary outer wall. Also I did not add Green Glue into the equation because I do not know but from Stuart's information in Green Glue Test Results those figures will improve yet further.

My only concern is the rumbling lorries so close. That needs a professional to advise, along with the windows.

Alan, by bunker I pictured something like this, not subterranean.

Source of the postI have always understood from Rod, Stuart ...

I see what you did there. Clever.

[Wheresthedug]

Thanks Eric and Starlight. Your input is MUCH appreciated.

Starlight: I also worry about the lorries although logging in Scotland is a bit smaller scale than places like the US and Canada. We have a maximum of eight loads a day which typically go past in pairs. They either don’t run in the winter months or only run in dramatically reduced numbers (I can’t remember exactly what the approved traffic plan said). They are restricted to 10mph. Normally this would be a laughable restriction as drivers just ignore speed limits. However, in our case they access the forest over our private road. The forest owners only have a right of access but that is obviously subject to adhering to agreed terms and conditions which we can enforce. There are also strict speeding terms in the agreement. I can’t remember the exact penalties but it something like; Any driver caught speeding gets suspended for 1 week, second offence 2 weeks and third time gets them fired. Worst case scenario is I install massive speed bumps before my property and just after it (but not so close that the noise of crossing the bumps is worse than the normal noise of the lorries.

I see what you mean. When I think “bunker” I think like underground bomb shelter. There is actually an old underground bomb shelter about half an hour away which the BBC used as a studio at one time. The guy who runs the tech side of our community broadband project Is the current “chief scientist” at the BBC and he bought it when they stopped using it. I think he has turned it into a sever farm now.

Rod Stewart photo;

[endorka]

LOL at the Rod Stewart photie

I'm glad you're be getting Stuart to design the studio, that level of isolation and custom build is absolutely calling for a specialist.

Had you considered aiming for a lower f0 than 22Hz? My knowledge is limited, but gather that will be effective at isolating sounds above 31Hz (1.4 x 22Hz) = ~31Hz. That's the pitch of the low B on a six string bass, and therefore useful for isolating music. I imagine the rumble from the log lorries will go lower than that though, and a few more layers of plasterboard on the inner leaf could get f0 closer to the lower pitch threshold of human hearing.

Your post brought to mind a recording session from years ago, where the sound of a nearby subway made its way (albeit very quietly) into the mics when recording quiet acoustic instruments.

Cheers,
Jennifer

[Starlight]

Source of the postHad you considered aiming for a lower f0 than 22Hz?

22Hz was just the figure from my example of Alan making an inner room with 2 layers of 15mm fire-rated plasterboard. If he used 4 layers then f0 would drop to 16Hz; just another example.

Source of the postI'm glad you're be getting Stuart to design the studio, that level of isolation and custom build is absolutely calling for a specialist.

I couldn't agree more.

[Wheresthedug]

Thanks again guys. Stuart already designed a previous studio that I never got the chance to build. However, I did get the FULL Sketchup plans. The one thing that is truly obvious about them is just how much work is actually involved in doing a full design. I’m pretty good with a CAD program and understand the basic of the design principles but I definitely nowhere near being competent to design a full studio. I need to keep costs VERY tightly under control on the project so need to do as much as possible myself. However, I know for certain that trying to do the design work would be a false economy and would probably end up costing more in the long run for substantially worse results.

[Wheresthedug]

The roof went on the Studio and Workshop yesterday and I have finally managed to find time to post some pictures of the progress so far.

I can’t find many pictures of the setting out and laying foundations but here is the start of the build.

Looking down from a local viewpoint

With the slab in place we moved on to some SERIOUS scaffolding and a squad of brickies laid a few thousand concrete blocks.

We had some lovely days but there was no shortage of rain and the infamous Scottish Midge!

With the block work complete the prestressed concrete roof arrived. The arctic came the previous night and the driver slept in his cab until we arrived in the morning. We had a few extra hours hanging around as the poor hiab driver’s satnav took him down the “back road” which has a 7.5 ton bridge at the end of a single track road with no passing places. He had no option but to reverse back out until he eventually found a spot to turn then backtrack to the “main road”. I say main loosely (very loosely). It is still pretty much single track but at least has passing places and no bridge with a weight restriction at the end of it.

Once he got started the whole roof went on in about 3 hours. The driver/crane operator was amazing!

It now feels like a real building. It is pretty much a concrete bunker as @Starllight suggested. However, you can see that the windows are a “little” larger than standard bunker slits. This is the reason for my concern about required glass thickness.

[Starlight]

Thank you for the photos and progress report. It looks big. What is the section with the lower roof going to be?

[Wheresthedug]

A few more pictures that give perspective on the overall project and location.

These show how close/far the studio is from the main house.

Our closest neighbour will be building to the west somewhere between the oak tree with the shipping container beneath it and the white van.

Our closest neighbour to the south is visible in the top right of this picture. It looks like we should have nothing to worry about when it comes to annoying the neighbours but sound really travels in the glen. I haven’t measured the ambient noise on a still day yet but it is QUIET. Like silent ! There is more noise from my tinnitus than there is in the glen itself and I don’t want to be the one who disturbs this tranquility.

[Wheresthedug]

Source of the post Thank you for the photos and progress report. It looks big. What is the section with the lower roof going to be?

There isn’t really a section with a lower roof. The whole roof has a 7 degree slope. The highest end is in the live room and the lowest end at the back of the control room.

The other side (leg of the L) is a guitar making and repair workshop. There is another bit of roof still to be added and supported on a steel post. Thos will Allow a car or van to be reversed right up to the door and provide cover from the rain While unloading. Of course this won’t really ever be needed as it never rains in this part of the world

[SoWhat]

So how much was the helicopter rental for those aerial shots???

Thanks for sharing the photos. Wow.

All the best,

Paul

[Wheresthedug]

Source of the post So how much was the helicopter rental for those aerial shots???

The building company had a drone as they wanted to use the pictures for their own marketing.

[endorka]

That is incredible, nice one! I can't wait to see how the windows are done!

Cheers,
Jennifer