VO-BB - 20 YEARS OLD!

[Rob Ellis]

Okay, here are some photos




It's about 7.5 feet high, I would say about 7 high on the inside.

Below are some interior photos





[size=12]The bass traps are stacked almost to the ceiling, and are the Auralex LENRDS,[/size]


And here is the room

[Mike Sommer]

First impressions is that your bass traps are not deep enough to offer any
real control. And Like I tell everyone the foam just does not offer the
absorption to control the modes in a small room.

Calculating the wall area (not including ceiling or floor) you have 105 square
feet of wall. If you were to cover the walls floor to ceiling with 2" of 703
your numbers should look like this:
125Hz @ 0.12 sec
250Hz @ 0.06 sec
500Hz @ 0.03 sec
1000Hz @ 0.03 sec
2000Hz @ 0.03 sec
4000Hz @ 0.03 sec

This is too dead, with no control of the bass.

Cover the upper half of the booth with 2" of 703 and you should get
numbers like this:
125Hz @ 0.11 sec
250Hz @ 0.11 sec
500Hz @ 0.06 sec
1000Hz @ 0.06 sec
2000Hz @ 0.06 sec
4000Hz @ 0.05 sec

This is much closer to what you need, and by adding 4" of 703 on the ceiling
with a 2 to 4 inch air gap and you should take care of the bass.

If you treat the upper half of the booth with 4" of 703 here is what you get:
125Hz @ 0.07 sec
250Hz @ 0.07 sec
500Hz @ 0.07 sec
1000Hz @ 0.07 sec
2000Hz @ 0.07 sec
4000Hz @ 0.07 sec

Hello! We hit pay dirt. Though I would still place 2 or 4 inches of 703 on
the ceiling, and 2'x2' x2" panels around the bottom half to control the
resonance of the booth.

Note the actual performance with your booth may very, but this is a good start.
It's all about tweaking playing with the acoustics until it sounds right to you.
_________________
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.

[Rob Ellis]

Wow!

So are you saying put 2" 703 on the walls floor to ceiling, and 4" 703
on the ceiling?

Would I still need the bass traps? They have definitely removed some of the boominess.

Would traps made out of the 705 do a better job?

[BenWils]

Just want to say....if you need to get a booth, get a Gretch Ken (GK Booth/Soundsuckers) with an added layer of heavy load vinyl.

You will have more space inside (since it is single walled) and they seem to have less problems with the bass nodes than the double walled WR booths, in my opinion. I have been in a few.

If you have a quiet room with no intrusion of neighbor's lawnmowers and road noise/traffic, wind noise from a window etc, then you may be good without a booth. But, I have heard some people's recording areas where they thought it was silent....and it wasn't.

We all do what we have to do....so if it works well for what you're doing and your clients are good to go...that is all that matters.
_________________
Ben


"To be really good at voiceover, you need to improve your footwork and hip snap."

[Rob Ellis]

Here are some specs on the Auralex LENRD bass traps

[Mike Sommer]

Rob,

What I'm suggesting is covering the top 4' of your booth, up to the ceiling corner, and from standing corner to standing corner with 4" 703/rigid fiberglass. Then install a cloud trap on the ceiling, the thicker the better, and more air gap the better. Then place 2' x 2' x 2" thick panels on the center of the lower portion of the wall
to suck up the resonance.

By placing the fiberglass corner to corner it will act as a bass trap, and having the cloud trap on the ceiling with the air gap you are making a very effective bass trap.

You could install your Lenrd bass traps on top of the fiberglass but I don't believe you will need them.


The Lenrd bass trap are nice but, as a total system with the pyramid foam on the walls you are creating diffusion (scattered reflection) which is ok for large rooms, but for small rooms one needs absorption to absorb the rooms resonance. To do this with foam you'll need close to 6"; you can buy a mountain of fiberglass for the price of 6" foam.

All I can say is once you start installing rigid fiberglass in your booth, you'll become a fiberglass junky.
~If you need me to illustrate this for you let me know~


As for Gretch Ken, Whisper Room, or any small box like inclosure and the Cube-Like dimensions are nightmares to deal with in terms of modes and nodes. Modes and Nodes have nothing to do with construction but rather dimension.
_________________
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.

[BenWils]

I have been in both booths and I own the GK. I would say if the GK was worse. I am not posting on here to mislead people because I want my booth to be better. Merely offering advice to those that want to buy a booth based on my actual experiences.

I did have to add bass traps in my booth. But it is dialed in now and sounds great and I have not had one complaint from anyone. In fact, like I have said before, I have had several heavy weight studios compliment me on the sound.

I agree that the fiberglass is probably much better for trapping and treating inside one of these overpriced boxes. So if you have to get a booth, budget for treatment of the booth.
_________________
Ben


"To be really good at voiceover, you need to improve your footwork and hip snap."

[Mike Sommer]

[Rob Ellis]

Well I am moving forward on the OC 703 but man, these online folks seem a bit pricey....

I found a place locally that says they have the OC 703 with either the foil or paper backing, for 1.20 and 1.29 /sf, respectively. (which BTW, after shipping, is about $100 less than the online source)

I hadn't considered the "backing", but want to make sure before pulling the trigger, as I have learned to do with these kinds of expenditures.

Anybody know whether the backing they're referring to makes a difference as far as sound absorption goes?

[Deirdre]

You want NO BACKING, Mate.
(I didn't know it came with "backing".)

Anything solid will reflect sound, I do bleeb.

You need this stuff:


From guys like readyacoustics.com or atsacoustics.com.
_________________
DBCooperVO.com
IMDB

[Mike Sommer]

Yes, the facing will make a difference -FRK and ASJ offer less absorption in the
higher frequencies, because the facing is reflective. But you can peel it
off.

If you use 703 FRK the foil side should face the inside the room, this will
offer more reflective shimmer while providing a little more bass trapping -
much like a "Low Bass Panel Absorber". BUT! In small rooms this can be a
bad idea. In your situation as in most, you need the broadband absorption
of non faced 703. Also, if you try to use the 703 FRK, with the foil side to
the wall, with an air gap, the air gat will be defeated by the foil.

Expect to pay about $90 to $100 for a bale.

There is also a product called Insul-SHELID, from Johns Manville.

Seek out Air Conditioning companies, they tend to use rigid insulation more
than anyone.

http://www.owenscorningcommercial.com/docs/specification/Fiberglas700Series.pdf
_________________
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.

[Rob Ellis]

So is it time to ebay or Craigslist the LENRD bass traps, or do the ones in
the listening area still have usefulness?

[Mike Sommer]

I would be prudent about this. Make the changes and see how you like it. After that you can try adding the traps or add a few squares or the pyramid foam on top of the 703. It's nice to be able to test and try new things when treating and tuning a room.
_________________
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]

Am I reading the dimensions right? 3.5 X 3.5 X 7? Why would a company that specialises in making sound booths make booths in acoustic nightmare dimensions?
_________________
Mandarin Chinese Voiceovers & Localization
http://lcmsmedia.com
http://imagesbykenny.com/

[Mike Sommer]

Simple- the economics from which the material that they are built from - 4'x8' sheet product. Most of these booths dimensions are devisable by 4 or 2, 2 being a half sheet.

Problem is most structural sheet products do not have the density to provide the isolation needed in most situations. Adding Mass load Vinyl will help, but when you consider that one needs over an inch of drywall on a double wall/two leaf system often with Vinyl between layers to get the kind of isolation needed is most situations. These booths pale in comparison. (Drywall is denser than plywood. Though MDF does start to approach the mass needed in arresting sound infiltration, this is only half the picture for sound isolation.)

These companies are targeting a niches market. A group of people who want a booth, and charge a premium price for there product. These products perform at a marginal rate, as is, in desirable conditions, i.e. low noise conditions.

But when it comes down to it one is better off finding a quiet location and a larger room and spending the money treating the room.

It is my opinion that these companies specialize in nothing more than profit to an unsuspecting and uninformed consumer. How else can one explain slapping some speaker carpet on some plywood, add some fancy fittings and call it a booth. Well, it is -a booth a sweat booth- with poor design, that needs treatment after you get it home.

Now before everyone starts jumping on me for bashing these booths. Let me just say, they are what they are. For some people these booths maybe just what the Doctor ordered. But they were not designed with acoustical considerations in mind, as much as the efficient use of the material. And any booth or room under 1500 cubic feet will need considerable treatment.
_________________
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.