John Sayers' Recording Studio Design Forum Archive

i got the error but i took the "s" out of https and it worked fine. it looks like you added the soffit for the pipes - good. on the slats nearest the speakers - make those short slats just cloth cover absorbers. effectively the entire short angled side is absorptive top to bottom.

BriHar wrote:

xSpace wrote:SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message.

Is that another way of saying it got a friendly kick in the pants and took offence?

I don't know Diffle or Hellman but I used to go hiking with a Duffle bag which often contained Hellman's mayo...

Jeepers'
...and April 1st is already gone...

I've tried the link from a few other PCs - including from work where we've got firewalls and scanners galore, and I've had no problem.

Anyone else have problems with the link?

Pretty much anyone outside of your network is going to have an issue with it. As Glenn said, removing the "S" which reduces the protocol to a HyperTextTranferProtocol from the SPECIFIED SECUERHyperTextTransferProtocol is a vast difference...it's the Internet and everything is for a reason.

RJRollins is full of @#$%, the link did not work for him in the current secured form, assuming the "s" was not removed from the https protocol.

OK I edited the post and removed the offending "s". It should work now.

xSpace wrote: RJRollins is full of @#$%, the link did not work for him in the current secured form, assuming the "s" was not removed from the https protocol.

HAH ... Maybe you didn't try 'SAVE TARGET AS' .... that's what I used ... the file showed
up.

RJHollins wrote:

xSpace wrote: RJRollins is full of @#$%, the link did not work for him in the current secured form, assuming the "s" was not removed from the https protocol.

HAH ... Maybe you didn't try 'SAVE TARGET AS' .... that's what I used ... the file showed
up.

I see.


Well, if every link has to have instructions...then that should be documented as to how to document can be accessed.


You got lucky, that is the way you work your on-line experience, I did what the man asked and it failed....but the Internet does that on a regular basis:)

Hi, not sure if u went @ ur block wall yet but I had the same dilemma in my studio build, here is a link to what i did -
http://www.johnlsayers.com/phpBB2/viewt ... =2&t=14252

After I waterproofed the wall with that thick black rubbery paint i plastered it with a thin layer of gypsum render, there was a bit of work in it but the wall is definately sealed

keep up the good work
hally

Well, we've taken possesion of our new place, and I've managed to get a little time to make a few tests.

I set up a stereo system with the Cerwin Vega speakers.

First, the room is absolutely radio dead! I can't even get the tiniest hint of a radio signal on any of the bands FM, AM, LW. So, I'll have no worries about external RF interference.

Secondly, the room is incredibly quiet. Testing ambient sound levels gave readings of 29.8 dBa and 36.3 dBc. These levels are pretty much consistent even when aircraft fly overhead (the building is at the beginning of an approach corridor for Zürich Airport). The aircraft are quite loud outside especially when they engage the airbrakes or flaps, but in my studio room even without any additional isolation or treatments I can't even hear them and readings may add an additional dB.
The only disruption comes from that black drainpipe on the back wall (which I've taken to call the "Plop-Pipe") whenever anyone showers or flushes - the latter being the worst case. I knew this pipe would need isolating, but it's obvious it will need some special attention.

Using Soundcheck CD, reference tone 1kHz at 100dB and then a ramp from 20Hz to 20kHz gave readings as follows: The high ambient level in the Anteroom B is due to the air vent blowing air into the room.
Rooms G & H weren't accessible for my tests.
Room F had a lot of boxed goods so I imagine a fair level of absorption.
The corridor J has the air ventilation duct with a vent , downwind if you will from the studio.
The Carpark D could not get a reading above ambient but the test tone could be very slightly heard at certain registers.

cool! maybe just put the "recording in session" light up in the bathroom so people know to hold it while you record...

Hello Glenn,
Unfortunately we have no Icon for a lead balloon.


Doing the math...

I figure I should have to add additional Isolation for 10 -12 dB on the AF,AG and AB walls. The Partition AF shows it would require 10.8 dB, the AB is not important with respect to the room B - only in relationship to the corridor C . The AG partition will probably be very similar although this partition is even thicker.

Would a single layer of 12mm drywall on my inside frames, with insulation of course, be enough?

Would 18mm drywall be better, or overkill?

According to John's STC chart in the Recording Manual, a simple Brick wall has a typical STC of 39. A brick veneer wall with 10mm dyrwall + Insulation has an STC of 55. This would seem to indicate that the addition of the drywall and insulation should add about 16 STC.

My existing walls should have an STC of about 45 - 50. Can this be calculated with the existing figures?
100 - 47 = 53, or (47-36.2)-(100-36.3) = 52.9?

so on mass law alone, to double (6db) a given isolation for a given mass requires an additional 2x the mass, so probably 2x 19mm (or 18mm) drywall would seem to get your to the 6db mark. some green glue might be useful in this case. then once you have increased the mass of the walls and ceilings, the TL is impacted by the flanking through the floor and structure so decoupling is needed in the equation. this might be a damped membrane floor as a means of reducing the floor transfer. door seals and increasing the mass of the doors would be important as well.

18mm is available here as is 12.5mm, 16mm and 19mm would have to be ordered specially ($$$). There are also the laminated drywall panels which I showed in a previous post which have an overlapping lip for interlocking panels. These are about 24 or 25mm thick.
Green Glue is totally unheard of here it seems, at least the stuff we're talking about. It would appear Scotch makes a product called "Scotch Green Glue Universal", which is something entirely different. Sounds like a trademark infringement if you ask me.

The existing brick walls are decoupled from the concrete. The 25cm thick concrete ceiling as I mentioned is covered with 100mm thick FG Panels with a cloth facing. The concrete floor will be covered with a thick Novilon.

The door was unfortunately mounted contrary to my specification - i.e. it opens inwards to the studio room. This will be changed so that I can add a heavy 2nd inner door. Both doors (cellar and inner studio doors) are not solid but are well sealed with gasket top and sides. I am surprised how much sound they do in fact stop - my wife came down the other day when I was listening at about 70dB and until she came into the outer cellar room had no idea I was listening to music at all.

There is a space at the bottom of the door, and this is to facilitate air circulation. Fresh air is pumped into the cellar room and extracted in the studio room. This might help explain why the sound leakage through this door is reduced because of the pressure differential forcing the air in the opposite direction.
I'm thinking of putting in a door jam with gasket seal, then installing a vent near the bottom of the door. I could then mount a silencer on one side of the door. Problem though with a second inner door... simply cutting a vented port into the second door would seem to undermine the effort of building an "isolation" door.
Better yet would be to drill a 6" hole in the wall with a vent on the cellar side, and a silencer on the studio side between the brick and inner isolation walls.

I'm going to have to adjust my framing a bit as the pipes have gotten fatter. They now sport a thick insulation. Shouldn't pose a problem except for the congestion at the ceiling by the "plop pipe".
Also, now that the walls are painted, the holes and spaces between the bricks is easier to see. Nothing major, the larger spaces I already had them fill with mortar. The remaining ones I'll fill with plaster.

The decoupling between the brick walls and the concrete has a space: I'm going to fill this with caulking, also the space between the ventilation duct and the edges of the hole in the brick walls will be caulked.

Here is the air intake in the cellar room: And the door: Any thoughts on air flow between the two rooms?

OK, I've checked out some sources. I can get 12.5mm drywall and 15mm. I can get a pallet of 60 12.5mm boards 600 x 1200 for SFr 414 that's SFr 6.90/panel or single boards @ SFr 8.90. I've got a quote for 15mm panels 1250 x 2500 @ SFr 12.90 / m² that would be SFr 40.25 per panel or SFr 1207 for 30 panels. That is ridiculous.

Can I use 3 layers of 12.5mm instead of 2 layers of 15mm?

Can I use 3 layers of 12.5mm instead of 2 layers of 15mm?

Nope! That stuff is not good for isolation: too thin, too flexible, low surface mass, high resonant frequency, etc. Not good. Maybe look around for a different supplier, with more reasonable prices on the 15mm stuff!


- Stuart -

Thanks for the reply Stuart, I was afraid of that, but I don't know exactly why. This is one of those grey areas for me. Maybe you can give one of your clear explanations.

Assuming the two panels are made of the same material which has a specific density, the 16mm panel will be denser by reason of it being thicker, therefore it will have a lower resonant frequency, plus more mass for isolation. I think I understand that much.

Adding a second layer of 16mm will increase the total wall mass, and will increase the total density therefore also lowering the RF even further. Is that correct?

To quote you from another post:

To REDUCE your resonant frequency (ie, make your wall isolate better) you can either add more mass (more layers of drywall) or you can increase the size of the air gap. Or both.

2 layers of 16mm = 32mm and 3 layers of 12.5mm = 37.5mm.
Surely this is more mass than a double 16mm wall?

Why will it not have a lower RF?

Can you possibly explain this with numbers?