Portable Dead(ening) Room

[Lamoni]

Hi there,

I have spent a few months looking through this forum, and finally decided to resister as it will help in my career.

Although I've read about comperable insulation, how to create a sound-proof wall, studio design, and just about every topic on here, I'm still not confident on how to achieve what I want.

I'm looking to create a "dead(ening)" room that can put up and taken down for purposes of voice over construction. Due to size limitations, it's not possible to convert a room, or acoustically treat a room as some rooms are too large, and others are much too small.

As it is, I'm thinking of making a pentagonal free-standing structure where all five sides can be taken apart and stored. I'm striving for about 6 feet in length by four and a half feet in width(at the widest part), using mineral wool strapped either into a 1x4 frame, or onto a 2x2 frame with fabric(comperable to burlap, but not so rough). The effect would be a small space cut off from extraneous noise, but not entirely soundproof.

The space is a finished basement with a laundry room created by floating walls(simple wood panelling on 2x4s, from floor to suspended ceiling), a bathroom, and partitioned in half with other floating walls. The space I have to work in in the open basement is 7 feet by 12 feet. The noises I have to deal with in my space, in order from closest to working space, to furthest are running water from a fishtank, bird chirps from a bird cage, a fan from a gas stove/fireplace, the fans from the computer(across the partition), and at times the washing machine/dryer(in their own room, but still audible).

Any input would be greatly appreciated on the current plan, or recommendations for a new one.

Thank you,

-Lamoni

[len-morgan]

If you really can't construct anything to stay in the room then your choices (and the results you can expect) are limited:

The noises I have to deal with in my space, in order from closest to working space, to furthest are running water from a fishtank,

Stop the pump when you hit the record button

bird chirps from a bird cage,

move the bird when you are recording

a fan from a gas stove/fireplace,

turn off the stove/fireplace while you are recording

the fans from the computer(across the partition),

get quieter fans for the computer and/or build an iso-box around it. (Are you starting to notice a pattern here)?

and at times the washing machine/dryer(in their own room, but still audible).

I'll leave this answer as an exercise for the reader.

What I'm getting at is you don't get sumthin' for nothin'. You want ISOLATION and that requires MASS and (where acheivable) air-tightness which you aren't going to be able to get with movable panels. The panels you are talking about are not for isolation but for absorbtion - not of incoming sound but absorbtion of reflections.

If you can't do the "full-up" studio build, it does sound like with a little cooperation with the others in the house, you can reduce the outside noise while you are recording.

len

[Lamoni]

Thanks for the prompt, yet overly condescending reply.

Any ideas on how to deal with the "open air" sound? Section off part of the room with absorbant material? Or leave it for post?

-Lamoni

[len-morgan]

Sorry, I didn't mean to be condesending but you'd be surprised how many people want to turn a warehouse into a "world class studio" but don't want to spend more than $200 to do it, and oh, by the way, it needs to be finished this weekend.

As to "air", I might be a little more helpful. What you describe as air is probably just reflections around the room. You could probably make some gobos out of rigid fiberglass or mineral wool and cover them with cloth (like a pillow case only bigger). If you suspect floor to ceiling reflections, you could lay one down in front of you. If you put these around you, you'll more than likely go too far the other way (i.e., too dead) but you can add back in reverb and some "space" later. It's much more difficult to take it out once it's been recorded.

Hope that is helpful (and a little less condesending - you caught me at a bad time).

len

[jwl]

Hi there, how much isolation do you want? You can get very good results with gobos. I think it'd be a challenge to build such a room, though I have seen ads for prefab pentagonal rooms as you describe.

I suspect that for voiceover work, absorptive gobos would be adequate. I just built 6 gobos and I was very pleased with how well they isolate from ambient background noise, and how good things sound inside them. But then again I'm conscious that I'm probably suffering from the "I built it and it works for me so it must work for EVERYONE!!!!!!!" syndrome....

[Lamoni]

Thanks, you have both been very helpful. I'll take a look at some designs for these and stuff, and work something out.

Thanks,

-Lamoni

[SonicClang]

I don't think it was condescending at all what he said. He was trying to illustrate that isolation and absorbtion are two totally different things. That's one of the big "battles" we fight in these forums, trying to teach that to new people. If you want to keep your "booth" removable, you have to sacrifice isolation.

What you're looking to do is this http://www.realtraps.com/products.htm#microtraps

[Lamoni]

This may be more appropriately placed in a recording thread, but it was related to the situation. Was just wondering if -53db (at peak) of surrounding noise is within acceptable parameters for raw voice recording. Are there any articles that could enlighten me on this subject? Most of the research I've done has been for room construction, acoustics, etc. I intend to actually construct a studio after my next move, as I'll likely have the room to be able to.

A sample mp3 of the mic input noise is available to any who requests it via email.

-Lamoni

[len-morgan]

-53 seems high. Is this the mic itself or after the pre-amp? I think self-noise on a reasonable condenser mic is about -92 (1000 times lower more or less).

len

[Lamoni]

After the pre-amp, technically. I'm running it only through a Eurorack 1204-FX mixer, with main outs going into an M-Audio sound card. The gain is almost all the way up, as is the slider. The test was done using a Shure SM-58 dynamic mic. I also own an Apex 175 shotgun condenser, which has two modes - normal and telescopic(shotgun mode).

Oh, and the level of noise was measured after normalizing the vocals on the track to -.1db

-Lamoni

[len-morgan]

That sounds like a lot of gain for a dynamic mic. (Just a thought, it doesn't require phantom power does it?) Is your mixer a Berhinger? They tend to be a little on the hissy side.

len

[Lamoni]

Yeah, it is. It's quiet as death on anything that isn't a mic, though. Think maybe a seperate rack-mount pre-amp might do the trick? Also, would you recommend an expander or compressor for vocals? If so, what would be required from it? I deal a lot with my local Long & McQuade, and am usually able to find some good equipment for decent prices.

Edit: Nope, it doesn't require phantom power, but I'll run some through it just to see if it makes a difference. Shouldn't harm it any, as it's a professional dynamic mic. I know what you mean by hissy though, even without a microphone (or even cable) attached, it hisses slightly at no gain, no slider, and quite noticeably at higher gain levels. So I could very well need a seperate mic preamp to circumvent this flaw.

Thanks,

-Lamoni

[jwl]

Yeah, it is. It's quiet as death on anything that isn't a mic, though.

Sounds like it's the mic preamps in the mixer that are adding much of the hiss.... I definitely think you'd get better performance from a separate mic pre, even some of the cheapies like an ART TubePac or PreSonus BlueTube would be an upgrade....

[Lamoni]

That ART TubePac looks nice. I like the fact it has a built-in compressor, so I'll see if my local company can quote me a price.

-Lamoni

[len-morgan]

Have you tried NOT pluging in a mic and see if adjustment of gain and the fader makes the noise floor go up and down?

That might isolate the location of the noise.

len