VO-BB - 20 YEARS OLD!

[Living Culture]

Hi all
I moved a few months ago and have been steadily building my new booth, as opposed to glorified cubicle I was using before. However, it doesn't seem to be performing as it should. What do you think of this sample
http://lcmsmedia.com/clipstemp/
The microsoft sample is sample I mean. Google sample is reference to older "cubicle"

Since the chain is simple, KSM44-SSL Alpha Channel_Focusrite(via spdif) to PC, I assume the problem is with the booth.

I thought the booth has suffient bass trapping, with ceiling traps in 3 corners and corner trap in 1, all with about 4 - 6 inches of Rockwool. The walls are 2 inch on 2 walls and 4 and 6 on the other two (differences result from design issues)

Here are some photos for clarity.

http://www.facebook.com/photo.php?pid=31357748&l=1cba7055c3&id=1401843588

http://www.facebook.com/photo.php?pid=31357741&l=51308d6613&id=1401843588

http://www.facebook.com/photo.php?pid=31357747&l=0b5ee8c82c&id=1401843588
http://www.facebook.com/photo.php?pid=31405447&l=ad9711588e&id=1401843588[/url]
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http://lcmsmedia.com
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[Mike Sommer]

I think some of the construction techniques and materials are to blame here. Since I'm not standing in the room to really understand the problem, but seeing that you used plywood rather than drywall for the sheeting is, I'm sure, adding some resonance.

What you built is commonly known as an inside-out wall. Because of this design, the inert properties of the drywall are very important; the drywall actually acts as a bass trap, or membrane trap.
(I'm also gathering that you're not having any problems with outside noise isolation.)

Also what weight is the rock wool you used? you need material that weights 3 pounds per cubic foot, to be effective.

For the corner bass traps you need a minimum of 6-inches of rigid insulation, or superchunks.

You also don't have bass traps in any of the standing corners.

No panels on the door. ( is the door solid core?)

And almost a third of one wall is glass. ( Honestly I never understood the need the need of big windows-- or windows at all. They create more problems then they solve. If you need a window put it in the door and no bigger than 12" x 12".

My recommendations:

Lose the window and add a layer of 5/8" drywall to the wood using Green Glue. Or remove the plywood and add two layers of 5/8" drywall.

Add a 2" wideband panel on the door.

Install two superchunck bass traps in the corner where your mic is at, floor to ceiling.

Put a heavy rug on the wood floor.

Check the density of your mineral wool, you may need to add thickness to the walls.


NOTE: TO EVERYONE>
I'm here to help. Yes, I do charge for my extended detailed services, but they pale in comparison to having to rip everything out and starting over again.

For general advice and guidance I try to be very generous. But I, as well as George really hate it when we see stuff like this. We hate being he bears of bad news. So be smart, run stuff buy us first, before you build.
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Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

[Bailey]

[Mike Sommer]

Very good Grashoppa.
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Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

[Monk]

I hope to be building a new control room and vocal booth in the spring... you bet I'll send you preliminary ideas first.
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[Living Culture]

Hi Mike, thanks for the reply. Some of the decisions I made for construction were purely a result of available materials. I find it is difficult to get some raw materials in Taiwan.

[Living Culture]

Here is a sample with the changes.

http://lcmsmedia.com/clipstemp/Microsoft_12_23.wav
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Mandarin Chinese Voiceovers & Localization
http://lcmsmedia.com
http://imagesbykenny.com/

[Mike Sommer]

Since you don't have a problem with outside noise, remove the door. This will allow the bass in the corner to escape -- Yeah it's that easy. Of course if you don't have a problem with "Isolations" there was really no need the build the small booth, you would have been better off treating the larger room.

Try covering the the window, or as much as you can, and let's see how that sounds.

The monitor can be creating some kind of weird null; eliminating an odd frequency, especially if it really close to the mic.

There is something very strange going on in this room. The only way to discover this is to run a Room Analysis with programs like FuzzMeasure (Mac) or ETF from Acoustisoft. Using these programs will help pinpoint the problem. But all you can really do is just add another layer of insulation to the wall.

When you purchased the Mineral Wool there is a makers mark and a product number, with that information I can track down the density information for you.
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The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

[Living Culture]

To clarify, soundproofing wasn't my primary goal, but I still need to eliminate some outside noise (household/PC etc). I found that with the extra weight and panels on the door it gives just the right amount of isolation. I'll try a recording with the door open and see how it sounds. Or just put the extra trap on the door and deal with the door not opening fully (not really a big inconvenience)

I know just treating the whole room would have better. But I am renting here with a fussy landlord who doesn't want alterations made, so I went with the freestanding room.

To cover the window slightly, would the acoustic foam help? Or do I need to remove bass there, too?

I'm wondering if the aircon could be a factor.

The make of the rockwool is KMD (presumably a local brand), but no visible product number on packaging. I'll try find the invoice and see if its on there.

If it helps, the room is 38X59X79. The rockwool is 120cm X 60cm at 2" each. I used about 55 to 60 pieces.

I don't have ETF, but I can run an analysis with an Ultracurve or PAF software, should be similar.
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Mandarin Chinese Voiceovers & Localization
http://lcmsmedia.com
http://imagesbykenny.com/

[Mike Sommer]

Let me point out that the foam, at best, is doing very little except that it might be providing some diffusion, but again very little.

Whether it be fiberglass or foam, we need a density of 3-pound per cubic foot, to absorb a wideband of frequency.

In Standing corners bass trapping, using 2x4 feet panels, straddling across the corners, needs to be 6 inches thick. This will give you 24-inches across the corner-- the minimum about of bass traping required for the mitigation of bass frequencies.

I explain how to build Superchunks here:
http://www.vo-bb.com/phpBB2/viewtopic.php?t=12008&highlight=superchunk

If you have some rockwool just set it in the window to see what happens. OR if you have a heavy moving blanket, drape it across the window to eliminate the slap back.

The AC should not be a problem

You're also dealing with a slanted ceiling. This maybe the culprit of the odd sound you're getting. This is why we do not splay walls folks; doing so creates problems that are often untreatable, or the treatment is more expensive than the booth is worth.
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The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

[Living Culture]

[quote="Mike Sommer"]Let me point out that the foam, at best, is doing very little except that it might be providing some diffusion, but again very little.
Sure, its only working on some high frequencies. Actually, its only there because its the easiest way to make the booth look aesthetically OK. The joins on the material inside are hideous.

[Mike Sommer]

Keep moving forward and testing, not every booth comes out perfect the first time.


There is no real evidence that Air-gaps behind "conner" bass traps add any improvement, that's why superchunks work so much better. Where air-gaps do improve the performance, is on the wideband panels, those panels that set on flat walls or ceiling clouds.

So to reiterate: corner basstraps need 6-inches of rigid insulation on the face, or superchunks.
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The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

[asnively]

Does everyone need bass traps? Like girls, for example?
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[Living Culture]

[Mike Sommer]

Yes, every girl needs a man... er.. um Bass Trap-- or two, or three.
_________________
The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.