VO-BB - 20 YEARS OLD!

[nick]

Purpose

I need this booth primarily to shut out my roof mounted air conditioner and airplanes. The airplanes are not a problem most of the time, just when it is very windy and they change the traffic pattern. That is why I am considering only one layer of 3/4" MDF. However, I do not want to build this booth and then discover that it does not provide sufficient isolation.

Materials for Wall

I am thinking of MDF but there is also OSB, plywood, particle board, sheet rock and maybe some others. Should I go ahead with MDF or is there a reason to choose something else over MDF?

Wall Thickness

For my build, I want to keep the walls as thin as possible, so as to not take up more space than necessary. So, I am NOT thinking in terms of a stud wall. I prefer to use one layer or possibly two layers of sheet stock. I think that the minimum thickness should be 3/4" and this may work for this project because it is a "room within a room" so to speak. I am thinking that 1.5" would be the maximum needed. Does anyone have any experience to bring some light to this?

Bonding two 3/4" layers together may or may not be better than a single layer of 1.5" stock. Green glue is not an adhesive so I am not sure what would be the best adhesive if I go that route. I am thinking Silicone, because it is rubbery and would damp vibrations more than something like Liquid Nails.

Possible Configurations

One layer MDF: 3/4" --or-- 1" --or-- 1.25 --or-- 1.5"

Two bonded layers MDF: [3/4" + 1/2"] --or-- [3/4" + 3/4"]

Interior & Exterior Finish

I am thinking of using sheet vinyl flooring to cover the exterior. I think the weight and the bonding will help to tame vibrations by adding mass and damping.

I am thinking of using carpet tiles for the interior walls, so that I can make an interesting, colorful design. They will also add mass and damping. However, since the cheapest ones are $1/sq.ft. and I would need 157 sq.ft... I may go a different route.

Ceiling

I am thinking that the ceiling will have a rubber seal all the way around it and simply sit on top of the wall edges, being held down by its natural weight

Floor

Really have not thought this one through yet. Though it would initially be sitting on a carpeted slab, in the future, it may not. So, maybe two layers of plywood, with joists. Maybe have 12 casters on the bottom for some moveability, maybe not.

Door

32" x 1.5" solid core door

Window

Thinking of using a surveillance camera instead of a window. This will make construction easier, eliminate acoustic leaks and offer flexibility. I can place the camera to face any direction, so I can basically "move my window".

Faraday Cage

Not really... just kidding!


Would appreciate any and all input on this design!

[todd ellis]

have you considered how you will breathe?


not a joke.
_________________
"i know philip banks": todd ellis
who's/on/1st?

[nick]

[Lee Gordon]

I have a Fantech FG-4 that does an excellent job.
_________________
Lee Gordon, O.A.V.
Voice President of the United States
www.leegordonproductions.com
Twitter: @LeeGordonVoice

[nick]

[Monk]

I like the MDF idea, that stuff is heavy however and I'd be careful where you're building things. 4 walls of double MDF could add up to some serious weight issues.

That said. Mass and Air, you can caulk the seams of the MDF, squirt a bunch of Greenglue between the layers, and just screw them together. No need for bonding, the Greenglue gives you an elastic layer.

If you're building in the basement, then structural weight isn't as much of an issue.

Plan the door first, a good solid exterior grade door with gasketing. Think watertight. The smallest air leak lets in noise.

The sound of Jet noise is some pretty heavy duty low frequency. And you want to decouple from the structure that may transmit that noise through your booth. So some heavy rubber mat, much like that found in a horse barn, could be used to sit this thing on to further isolate it from the structure.
_________________
Company, villainous company, hath been the spoil of me...

www.monksvoice.com

[nick]

Thanks Monk.

Based on the experience and advice of yarg28, I am going to start with only one 3/4" panel of MDF, for the walls. With my design, it would be very easy to add another layer of MDF, to the exterior (after the build) should I need more. If I do that, I will use Green Glue per your suggestion.

My home is on a slab, so I do not have to worry about weight, other than the ease of assembly, disassembly and moving it around. At 4'x 6' x 7', I am guessing that the weight will be somewhere between 800 and 1200 pounds. Who knows?

My current plan is for a 36" solid core door. I do not remember where I got this tip, but the door will swing out, making access easier.

I struggled with the decision of whether or not, to use casters. Do I need them? This will be in a back bedroom and I would not be able to wheel it out a 30" doorway. I do not anticipate moving it around in the room but who knows what circumstances might arise that I would have to? So, in the end, I have decided to use casters. It's better to have them and not need them, than to not have them, and need them. Now I am debating 4" vs. 5" casters and 9 vs. 12 casters.

Any thoughts?

[ballenberg]

Lee, how are you using your Fantech? Does it pull air out and you have passive inflow? Baffles? Other add-ons? Is it quiet enough to record with it running? Thanks

[Lee Gordon]

I was going to post a link to a previous thread in which I posted pictures of the boxes I made for the intake and outlet, but those pics were all hosted on Photobucket and are no longer available. I'll move them to another host to post them, but meanwhile, I can tell you that my set up is just as you asked. I have two boxes with internal baffles and lined with the same sort of Auralex-like material I have on the walls inside the booth. The inlet side is passive and the outlet side is connected to the fan. Inside the booth with the door closed, you can't hear the fan, but you can hear the flow of air through the register, so I do not run it while I'm recording.

In the summer, it can get pretty hot inside my booth very quickly, so if I had to, I could record with the fan running and make a cleaning pass with Izotope's Voice De-Noise plug-in. I have experimented with it and am confident it works, but I still prefer to avoid using it.
_________________
Lee Gordon, O.A.V.
Voice President of the United States
www.leegordonproductions.com
Twitter: @LeeGordonVoice

[ballenberg]

Thanks Lee

[borja]

Hi nick,

I'm on the same boat as well, as I'm thinking to build my own booth (maybe next year If I'm not lazy enough).

You might want to check this project:


https://www.hispasonic.com/blogs/bricosound-x-paredes-lana-roca/37112

(It's in Spanish, but you can get an overall idea by looking at the pictures)


They use the following structure (from exterior to interior):

MDF | Mineral wool | MDF | Jetfal (vinyl) | PU foam (80Kg/m3) | MDF

Maybe a bit overkill for a voiceover booth, but you can get some useful tips, specially on the ventilation:



I'm not an acoustic expert but there are some critical aspects on this which need to be very carefully considered, like the door insulation or the structure layout, to make sure there are no points in the structure where the sound resonates and travels from layer to layer.
_________________
borja abad

[nick]

Thanks borja.

My booth will be a completely different type of construction, because I want to be able to assemble and disassemble it.
I want to isolate the panels and posts with strips of neoprene, or some type of rubber, maybe 3/16" (5mm) thick.
I intend to run it around all surfaces that make contact.

Previously, I had thought that I might not need a baffle box, if I ran a fan at low speed, but that is simply ridiculous. What?.
I sure wasn't thinking. I will absolutely need to use a baffle box, similar to the one you show in your post.
Otherwise, I would have two 4" diameter sound leaks in the wall, letting in outside noise... regardless of what noise the fan may or may not make. Duh!

BTW borja, I did not see those ventilation pics on the blog. There was only one page that I could see. Is there another page? Do they show the baffle box mounted on the booth?

More work to do!

[sounddguy]

Don't forget you need a way for fresh air to come in and old air to get out, not just one way if you create the airtight seal you need to keep sound out.

[borja]

[nick]

Hey... Thanks borja!