DIY Gobo Vocal Booth and materials used

[johnfunk]

Hello

First of all, I'd just like to say thanks to everyone for the many posts I've read and learned from over the past 2-3 weeks. This is my first post, but I've came to this site regularly for advice and each time I haven't had to ask anything, I've simply searched the forum and found an answer/solution I was looking for. Thanks!

Okay, Im an audio/music student and so have access to studios/equipment and dont really need to treat my living space at home. However, I find that my best ideas/inspiration for songs come late at night, when the rest of my 4 flatmates are asleep/relaxing.

What Im looking to create:

Some Gobos that can be put together and used as a vocal booth at home. These will primarily be used for sound absorption, but any additional, albeit small, isolation would be a good benefit. It simply to create a nice dead(ish) area for me to play in, and also reduce perceived noise levels in the room and so what can be heard by my flatmates.

I planned a very simply idea and guess what? The very same thing has already been done in exactly the way I was looking to do it. http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5928 jwl done a fantastic job of what I'm looking to create. Mine will probably be a more basic version of the same principal.

Im basically going to make 6.5' high gobos, 3' wide and 4" deep. This will consist of a simple frame into which (not mounted on) the fibre board will go. This will be covered in acoustic cloth. Thats it. Basically just big, oversized acoustic panels.

My questions:

1.
Im going to use this 4" Fibre board for the absorbtion. Its the 100mm thick, 60kg/m³ slabs. http://www.customaudiodesigns.co.uk/sou ... ng/amw.htm

Is this a good bet? It seems to have good absorption level, even towards the lower frequencies.

2.
Im going to group the gobos together to make a 4' x 4' booth (not completely square) and so have similar panel sat on top as a roof. Am I right in saying that this will at least muffle the perceived sound levels going into my room? I know they are mainly to absorb/treat the sound within the space I'll be singing/playing guitar, but with a 4" destiny, good absorption levels (the stuff Im using has small db attenuation levels too) and all round coverage, it should at least lower the perceived level by a few db?


3.Im using such a think absorber so that I can re-use it when I eventually build an iso booth. I think this material would be (and is intended to be) great within a mass air mass system. Will I be okay being in such close proximity to the fabric covered panels, for prolonged periods of time? I'll of cousre open the 'booth' up for fresh air.

4.
Finally,If I build an MDF room around these panels, (for a quick improvement in isolation, not as a full attempt at an iso booth) would I have to cover the MDF? since Im going to be in close proximity to them, I don't want to be breathing in MDF particles. I'll be using them a lot.


I've been researching lots of information/data sheets etc over the past while, and this is one of the main sites I come back to again and again. I've taken time to hopefully explain things as best I can, since I've noticed how helpful and knowledgeable you folks are from the responses on other threads that I've read.

Thanks in advance
John.

[Soundman2020]

Am I right in saying that this will at least muffle the perceived sound levels going into my room?

Slightly! But not very much.

Think of that stuff like a sponge, and think of sound like it was water. Can you use a barrier made of sponge to stop a river? There is your answer...

Seriously, it will help a bit, but I would not call it "isolation". A few dB at very best. Nothing to write home about. Effective isolation needs mass and a hermetic seal: that stuff has neither. It would probably be great treatment inside a booth, certainly, and also great damping in the cavity of an MSM system, but it isn't going to do a lot by itself.

Also, if you only have a few panels of that stuff around you while you sing and play, it is going to sound rather dead: Even in a booth you probably want at least some liveliness.


My 0$.02


- Stuart -

[johnfunk]

Thanks for the feedback Soundman2020.

Yeah, I didn't really expect it to isolate that much, just would have been a nice addition if it did, being 4" thick.

I've since thought of another idea which I wish i'd thought of earlier - its so simple.

-Buy some acoustic/sound blocking curtains or make my own with curtains and mlv.
-Build a frame with metal pluming piping.
-Install the curtains/sheeting to cover the whole frame with plenty overlap between sections.
-Seal up airgaps best I can
-Treat inside with 703 homemade panels

=Vocal booth.


I'm just trying to be inventive/creative with my methods. I cant see any reason why this set-up wont reduce db level by at least 10db. Yes, I'm aware of how much even a small air-gap can reduce the effectiveness of any isolation set-up. But like I said, even with that this should work!

The STC vales of these 16mm thick barriers is quite impressive: http://www.acoustic.co.uk/literature/heatshields.pdf

There are so many acoustic/sound blocking products available that can be used. (yes, again I know they are meant tt be used with this and in that way etc etc..........but I'm up for trying this idea out! Looking forward to it

[Soundman2020]

-Buy some acoustic/sound blocking curtains or make my own with curtains and mlv.

MLV? You didn't mention that you have a huge budget to do this, but if you are thinking of MLV then I guess you must have!!! That stuff aint cheap.

Seriously, MLV is reeeeaaaallllyyyy expensive mass. Sure, it works, but ordinary drywall (sheetrock) costs a small fraction of the price of MLV, and works just as well, if not better.

-Buy some acoustic/sound blocking curtains or make my own with curtains and mlv.
-Build a frame with metal pluming piping.
-Install the curtains/sheeting to cover the whole frame with plenty overlap between sections.
-Seal up airgaps best I can

If you are willing to go to all THAT trouble, then why not just build an ordinary booth? 2x4 wood studs instead of all that (expensive) metal piping, MDF/plywood/drywall instrad of all that (expensive) MLV, much less (expensive) overlap required, much less (expensive) sealing required, no (expensive) curtains required, and the 703 will be the same.

In other words, you can do a real booth, considerably cheaper and more easily than your "metal.plumbing-framed-heavily-overlapped-MLV-and-curtain-poorly-sealed-703-lined-facsimile-of-a-booth-that-hardly-isolates-at-all".

If you search the forum, you should be able to find many examples of home-built vocal booths. I've seem them somewhere, I just don't recall where.

The STC vales of these 16mm thick barriers is quite impressive: http://www.acoustic.co.uk/literature/heatshields.pdf

Those aren't STC ratings: They are TL numbers for several different frequencies. But anyway, compare those number with the equivalent numbers for ordinary 16mm drywall.... Then compare the cost....

There are so many acoustic/sound blocking products available that can be used.

Sure there are, if you have plenty of money to waste! But there are no magical, voodoo-powered materials that defy the laws of physics. ALL materials are limited by the laws of physics, without exception, despite claims to the contrary by some (unscrupulous) manufacturers. So in my book, I'd rather go with the absolute cheapest material that does the job, based on the laws of physics. But that's just me: if you have the money to spend on exotic materials that will not (and cannot) do the job any better, then by all means, go for it! It's your money, not mine. After all, the sound waves really don't care how much you pay for the mass. All they care about is the mass itself, not the price per kilogram...

For my money, if all I wanted was maybe 10 or 20 dB of TL and a "semi-portable" booth, I reckon I'd buy a few sheets of MDF, a bit of framing, a box of screws, some caulk, a couple of hinges, and the 703. Done deal!


- Stuart -

[johnfunk]

I'd buy a few sheets of MDF, a bit of framing, a box of screws, some caulk, a couple of hinges, and the 703

Yes, exactly what i would do. A LOT less hassle and A LOT cheaper.

However, I should have mentioned it has to be portable to the extent where I can move the whole thing to a new apartment many times over without having to hire a van. Also, part of the reason is due to the fact I have already in the past built a vocal booth with MDF. I had a very small flat/apartment at the time and the whole place had a continual musty/dusty air about it, still months after I had built it (out-with the apartment) You see, the vocal booth is to be stood in my living environment, not a spare garage/basement/office etc etc. This time round It will be in my bedroom. Not a nice place for at least 10 square meters of MDF to be sitting.

So.......thats why im using the mlv. Sorry to come on board with my crazy ideas. I don't have loads of money, but I see this as an investment in something that will make me happier than money in the bank makes me. Must be a bit out of depth on this forum, think its more catered to professional builds.

Anyway, thanks for the feedback, Im just looking forward to making the booth!

Cheers!
John

[johnfunk]

hmmmmm,

just been reading more, and have found that mlv is, well, not particularly favored on this forum (as wall isolation) and for good reason.

I would quite happily buy a few sections of a dense material if one existed that wouldn't fill my room with a kinda fine dusty air. Im not into believing all the scare stories about MDF, in case you are wondering. Its just from personal experience of having it in the room I live/sleep and it really gave me a dry scratchy throat/nose and airways etc.

You see, I firmly agree with most other people here. It dosent make sense to get mlv when you can just know up some drywall/mdf panels. So, I've got a few options, if they exist, and if you can help........

1) Can you 'treat' mdf, so that it 'traps' that stuff that seems to give some people (like me) a nasty airway?
2)Cover it up? Could I simply wrap something round it? Would that work?

If so, I'd be happy enough forgoing the mlv, and building a booth with alternative materials.....

[Soundman2020]

Plywood is roughly as dense as MDF (ballpark). If you don't like MDF, you could try plywood.

On the other hand, if you want to try something exotic that will work, then think of lead sheeting. Expensive, but very effective at isolation. Lead is several times denser than wood, so you could make it fairly thin and still get good isolation. Not quite sure how to seal the edges together, between sheets, but there must be a way. You might even be able to figure a way to make it in small sections that fit together, can be disassembled easily, and transported in a car. I wouldn't have a clue how to do that, but in theory it would work.

Drywall also fits the bill (as an alternative for MDF, not for lead). high density, cheap, easy to work with, easy to seal. But not very transportable.

There are options. Probably others too, that I didn't mention here.

- Stuart -

[AVare]

On the other hand, if you want to try something exotic that will work, then think of lead sheeting. Expensive, but very effective at isolation.

I don't know about expensive. Right now (Feb 12, 2010) you can buy 4' x 8' sheets of 1/16" lead for only $320. That's $10/ft2 or $2.50/lb. For those who are numerically challenged, that is an easy number to calculate costs with.

Numerically unchallenged,
Andre

[Soundman2020]

Damnit André!!!! Just when I think I have my basics all figured out for my build, you come along with a new curve ball that starts me questioning everything all over again!!!! Thanks!

Seriously, I hadn't really given lead a lot of thought for my build, due the perceived cost/benefit, but now that you mention those prices I started doing some research on sheet lead, and I'm starting to think it might not be out of the question. I just noticed that lead is about 16 times denser than drywall so 1mm of lead is roughly equivalent to 5/8" drywall, in terms of surface mass. So theoretically, I could get the same mass as three layers of drywall in just 18mm by using one layer of drywall and 2mm of lead. So I could gain 2 1/2 inches of room width! With my tiny space, that actually almost makes sense to do that. Now I just have to see if I can justify the cost...

I also found out that there are some companies that manufacture ready-made "sandwich" panels of drywall with lead sheet bonded to it: It is meant for hospital X-ray rooms, but should work just fine for an acoustic application I reckon.

AAAARRRGGGHHH!!!!!!

The other thing I was thinking of is for beefing up my existing roof deck: I had been planning to go the traditional route of carefully cutting strips of drywall to stick up there between the joists, but then it occurred to me that maybe just taking off the shingles and rolling out a 2mm layer of sheet lead on TOP of the roof deck, then putting the shingles back again, would be much easier, in terms of labor....

AAAARRRGGGHHH!!!!!! #2

Gee, thanks, André! Just when I thought I had it all neatly figured out...

(Actually, I'm sure you know that I mean the sarcasm in jest, André, and I sure do appreciate all the info you provide, and all the strange avenues you send me down.)


- Stuart -

[AVare]

Damnit André!!!! Just when I think I have my basics all figured out for my build, you come along with a new curve ball that starts me questioning everything all over again!!!! Thanks!

(Actually, I'm sure you know that I mean the sarcasm in jest, André, and I sure do appreciate all the info you provide, and all the strange avenues you send me down.)

You are welcome. I never thought I would write it with a basis in reality, but sheet lead lead makes QuietRock look like a bargain!

Andre

[Speedskater]

From my 1969 "Audio Cyclopedia" - On lead:

It has been demonstrated that if two equally effective barriers are constructed, one of lead and the other of conventional building materials, the lead barrier will be the lighter of the two.

[AVare]

It has been demonstrated that if two equally effective barriers are constructed, one of lead and the other of conventional building materials, the lead barrier will be the lighter of the two.

What is your point? No one disagrees that lead is an effective sound barrier material. The first and biggest limitation of lead is cost of the raw material. Nothing to do with acoustical appropriateness. Right now, lead is ~$2.50/lb and around here drywall is ~$0.15/lb. Lead is over 15 times as expensive as drywall.!

Economically,
Andre

[xSpace]

From my 1969 "Audio Cyclopedia" - On lead:

It has been demonstrated that if two equally effective barriers are constructed, one of lead and the other of conventional building materials, the lead barrier will be the lighter of the two.

This speaks directly to how effective lead is as a barrier and the density it [lead] has in comparison to the conventional building materials.

It will take a lot more sheetrock and MDF to get up to the ability of lead and that makes one mean ass heavy wall.