Tiny Podcasting Studio

Hello, I'm Jenny and I'm from the UK. I have been pondering how to convert one of my rooms into a small studio for Podcasting for the last 18 months and am trying to stop procrastinating and build something. I previously built a freestanding partition in another room (to make an extra bedroom) which worked out pretty well, but that was nothing like as involved as soundproofing (which should be a dirty word it's so darn tricky and £ostly). My budget is ridiculously small, basically about £100 per month for as long as it takes, I have acquired lots of old really solid fire doors for the main mass of my insulation as well as loads of glass that I'm not sure how I can utilise. Fortunately or otherwise the room is pretty small probably about 16` long (window side) x 9` deep x 14` high. Essentially the space will be divided between a Podcasting area with a desk, chroma key background, camera, lighting, mic, etc and a very small "cupboard" which will function as a server rack (will have a very large window so I can see the machine but not hear it) and vocal warm up booth (while being located adjacent and over the area of the only exterior window (sadly a very large window approx 4` wide x 13` high) so as to further reduce the ingress of outside noise into the studio and stop the servers whirring being more annoying than anything I have to say! Because of the nature of what I am doing I am not terribly loud though I did wish to incorporate a small booth for noisy vocal exercises and I'd like to play dvd's over my monitors without worrying about the noise. I live in a converted 18th Century Town house that is now a block of flats. Unfortunately because my studio will require considerable electricity I need to use the low rate (which for me is supplied by a separate fuse box which previously went to a large heater but will supply my lighting, fans etc). Because of this I will be using the studio during unsociable hours by necessity (and also because it is naturally quieter at night) and the sound proofing must protect my neighbours from me as much as the reverse while I still want the insulation to be sufficient that I don't have to re record everytime a lorry or motorbike goes past as I would now. Outside my building is a very busy road and railway (yes I know - could this be ANY harder! lol ). I will try to provide SPL levels when I get a meter, they are currently out of stock at Maplin. Essentially I only have to get the noise down to the same level as my laptop which is about 12db so it does not have to be perfect thankfully! The room I intend to convert, after much deliberation and one false start is (was) my bedroom because it is the largest room away from the front of the building where the train track is (50 meters away from the building). To help my brain cope I've tried to distill the information I've gathered so far into a simlple theoretical standpoint represented by my AIIM (aim - i.e. objective!) which is Absorption, Insulation, Isolation and MASS, the hardest to incorporate being isolation while simultaneously preserving insulation (air tightness), please let me know if my theory is missing any letters and what they stand for ;) I will provide full details of the room in due course and photos and a plan, unfortunately I've not been entirely successful running Sketchup using Linux / wine. The room suffers principly from sound transmitted through the ceiling into the studio and similarly from an external window through to the studio. Also to a lesser extent it suffers from sound through the door which leads to the interior of the building and I may discover if I can reduce those sounds sufficiently that there is some (principally impact) noise through the 3 of the walls (one brick two lath and plaster). The fourth which is also brick should be fine except perhaps from it's connection to the external brick wall. The building is fairly old and four stories so has relatively thick brick which is good (though I've tried drilling an inspection hole I cannot discern if it has a cavity which is frustrating as I cannot without that information know if in itself it constitutes 1 or 2 leaves, though I imagine it must be the latter. I have a few general questions though that do not relate to anything, except in reading the other posts I've now got as many; albeit different questions as when I started ;) Before you shout at me I really have tried to read and understand other posts but it is tricky and I have no aptitude for it. The first question is: When is a leaf not a leaf? To avoid any philosophical answers what I mean is, how much of the surface of an area has to be covered before it is considered a leaf? This relates to my project in two ways, firstly I have an issue with noise from above, but I have a nice ceiling and am rapidly coming to the conclusion that I must rip it out to avoid having three leaves. Firstly should I be looking to rip out the ceiling, I have been looking at the links and it seems that having 3 leaves is a waste of materials, but from what I see if the material is discounted (i.e. because the ceiling is already there then the difference between enclosing it between two other leaves or leaving it is small. I realise that you will probably say no to this, but I like the ceiling so I have to try to save it! Further, and to my question, how much of the ceiling would I have to remove for it to no longer constitute a leaf, would a large hole suffice to let the air pass freely or would I need to remove 50% or would I have to remove all but the joists? If I remove the ceiling which sadly I imagine I may have to, I was planning on hanging a ceiling suspended on isolators probably these http://cmsantivibration.co.uk/products/SFH-Range.htm but two things concern me and I will explain it with an analogy. that is that the isolated ceiling is like a plunger in a syringe and the air pressure from noise is much like moving the plunger up and down, in that firstly it must have a good seal, and secondly it must still be free to move. From what I understand the suspended leaf has to be air tight to be any good, it also has to be able to move, and that movement also has to figure in the expansion of the isolators through heating and cooling, and the sagging of the joists through moisture or drying, as well as the adding or removing large loads from the floor above and bangs, knocks from daily use. So how do I make a seal that is both air tight and flexible enough to move that much (presumably one or more centimeters) and should I use neoprene or fiberglass sheet to isolate the floating ceiling from the surrounding wall? Now I've explained my theoretical quandary I will explain the exact nature of my tentative solution. Firstly assuming I have to remove the ceiling I will firstly use the opportunity to add mass to the chipboard flooring upstairs (which I can only access from below) while at the same time sealing it to make it air tight. I thought for this I would use water tight sealant for the cracks in the chipboard and then either lath and plaster or stick gypsum up with wet plaster on the surface (to prevent air gaps) in order to completely seal and add mass to the floor. Under this I would put rigid rockwool of a reasonable thickness TBC. My plan is then to mount the isolators detailed above to the bottom of the joists and hang the false ceiling which would consist of 50mm hardwood (I have this and need to keep my costs down and isolation up) and finish this with one or more layers of gypsum as per your recommendations. The whole ceiling structure would probably run against fibreglass covered neoprene on the adjacent walls as tightly fitting as could be achieved. From this false ceiling would be hung a reasonably lightweight lighting grid and lights microphone camera etc. The rest of the project is far simpler than as avoiding impact noise from above is a high priority and technically the most difficult problem I think as well as ensuring that I can work in the wee small hours without there being any danger of annoying my neighbour. But briefly I plan to cover then window, unfortunately this will by it's nature HAVE to be 3 or four leaves and this is sadly unavoidable but I hope by making one of those leaves a reasonably large air space (a cupboard) this will reduce any proximity effects from the layering. Sadly as well any window covering must be removable and have a small opening (1/3 height door the height of the sash window opening) for a fire exit just in case. As far as the door is concerned I plan to have a couple of fire doors, one double and lipped with rubber seals of some type yet to be determined. and of the internal walls I may add more plaster to the existing walls but I will not be doing any room within room as it is beyond my budget. As for the external wall there may be a problem with low frequency noise though I suspect that the window will be the Achilles heal in my project and there seems no point trying to reduce the noise level beyond the weakest link in any case; so that I imagine will not require any work. Floor wise I'm pretty much ok as there is a shop beneath me which has clearly invested in some soundproofing and I planned only to add a thin cement floor approx 2" over the chipboard flooring, if I can do this and it wont chemically erode the chipboard or anything? I was thinking about adding linoleum to finish the floor but I need advise as to whether this will absorb the higher frequencies like carpet? I have posted some basic diagrams showing the existing room and my proposed soundproofing plans. If you got this far then thank you for sticking with me. Jenny

Just to say I've updated this with some basic (yes very basic I know) diagrams. BTW the booth pictured should not show a gap between itself and the existing wall that is an error. BTW the LAST picture is the picture how the room is now and the first is the plan for how I wish it (broadly) to be. The main feature is the ceiling design that I hope to get feedback on. On the Plan the ceiling pipe "disappears" because rather than being below ceiling height as it is now it will be above the new isolated suspended ceiling in case you were wondering. What isn't shown is the ducting and air vent isolating box or axial fan but the direction of air flow is shown. Rockwool shown will be framed and covered. Thanks! Have a great day. Jenny

I have just drafted my idea for a window plug for your comments and suggestions. The Plug is behind a sash window. The first layer is a porous waterproof fabric designed to prevent water of condensation from the outside or behind the sash window infiltrating the Rockwool. The Rockwool itself is made of several layers of increasing thickness and will be composed of 100mm RWA45, 100mm RW3, 100mm RW5, and 100mm of RW6 in the hope that the varying thickness will absorb different frequencies better, but I welcome your feedback as my thought is that just going for the RW6 throughout may be better for reducing the principally low frequency traffic noise. The plug mass is composed of 100 - 150mm of hardwood perhaps with two of 3 layers of plasterboard facing the internal room. Do you think this plug is well designed and will be sufficient to prevent the traffic noise entering the room?

Jenteb, What I have gathered is that even a plug should abide by the mass/air/mass principle. To have an effective plug you want to have a dense layer on the outside as well as the inside. Think of it like you are trying to mimic the whole wall. In this case, the exterior wall. To be as effective as possible, this plug needs to approach the density that exists currently in your environment. I can assume there is a brick veneer exterior? Your mass is what is going to control frequency when it comes to street traffic. But the whole thing can be over-run by the structure borne vibration known as flanking. But still you must push forward with the plug of a mass/air/mass design.

xSpace wrote:

Jenteb, What I have gathered is that even a plug should abide by the mass/air/mass principle

I did worry about this, it is a problem for me as the exterior of the building is listed and cannot be changed and so the mass-air-mass that I would have liked is out of the question, the only option I have is to use the existing windows as the first mass, albeit they are only small mass. If I could change the exterior I would just brick it up with engineering bricks on the external wall, insulate and brick the interior wall (that is the wall is composed of two brick walls separated by a gap. Because this is not possible I was hoping to get enough reduction for my purposes by attaching dense wood mass to the interior wall and padding the gap between the window and wood with lots of rockwool. In this way I can fit waterproof black fabric behind the window and from the outside it will appear as a curtain or darkened room. I know this isn't perfect but I was wondering if it would be enough for my purposes.

But the whole thing can be over-run by the structure borne vibration known as flanking. .

At a push I could fit a false wall behind the existing brick wall along it's entire length including covering the window plug, I was hoping this wouldn't be necessary but it is an option. Thanks for your reply Jenny

You could set the plug up similar to Johns' inside out wall. Mass on the outside part of the plug then covered insulation on the inside? It doesn't have to be brick :)

Aloha Jen, There was a thread in which poster & Steve (knightfly) had detailed a window plug assembly sometime ago. Try the search function and keywords "window plug." After that, its a matter of reading through and finding the appropriate thread. Its a bit of research for sure, but there's tons of info to be learned and the same process of research for all of us. If you (or one of us :wink:) find it, be sure to post a link to it for future reference. Good luck and happy reading! :D Aloha 8)

As written, you need mass for isolation. You could make the leaf of the plug to include lead. Andre

AVare wrote:

As written, you need mass for isolation. You could make the leaf of the plug to include lead. Andre

Yes that is a good idea and I am considering it, though it would be very, very expensive from what I can tell, but I will be able to access the plug so I could upgrade the plug over time with a lead layer. Jenny

jenteb wrote:

Yes that is a good idea and I am considering it, though it would be very, very expensive from what I can tell, but I will be able to access the plug so I could upgrade the plug over time with a lead layer. Jenny

And? You are beside a busy roadway and train line. You know that isoaltion is not cheap. If lead too expensive then use steel. Right now the world market for it such that it is so cheap that recyclers do not even bother picking it up. Andre

I've been considering my plans and some of the replys and in particular worrying about the multiple leaves problem. I have come across an issue that there may be asbestos insulation above the existing ceiling and now I am reluctant to break the plaster "seal" and risk exposing myself. I had previously considered a large room within a room design but I had dismissed it on the basis that it was too expensive and heavy to be positioned on a first floor. I have since then and with worrying about the leaves problem realised that I may be better going back to this. Having previously made a small booth I have some experience with this type of thing and I can just have one leaf so as not to waste time, money, or materials on some counterproductive effort. For my design I am considering framing the hardwood doors that I have so as to make individual panels that can be bolted together (at right angles to the mass not through it) so that it can be disassembled, moved, or extended. I also plan to treat my existing walls as the first leaf and put acoustic absorption mounted on the outside of the inner room to reduce sound traveling between the existing walls and inner room as well as inside the entire inner room for absorption (hopefully uniformly across the sound frequency spectrum if possible). The panels will be made such that I can add mass or a second mass layer at a future time if required and will be faced both sides with Rockwool. I may also float the entire structure on neoprene feet if necessary and in the future, as the whole thing will disassemble I should have this option or I could jack it up en masse. With this plan there will only be two leaves, the exterior wall and the "inner room", which I hope will be the most efficient use of resources providing the best STC / mass ratio.