Portable Room Treatment

[ChuckS]

I'm considering building a portable 'gobo' type of room treatment panel arrangement. I don't have a dedicated recording room, and sometimes record in different rooms, so it has to be something I can take down or move. I'm wondering if it is wise to try to build something to obtain a dry/dead space?

Here is what I was thinking of doing: for material I'm able to order in Roxul rockboard 80 from my local lumberyard; 4" total thickness. I was planning on (3) 6' high panels (one 3' wide and two 2' wide) and hinge them together into a U shape. Also thinking of having a panel to set over the top and a small one to use as a 'Jecklin disk'.

Is this a reasonably good way to get a portable treated space? Is this arrangement worth the time and money or should I consider something else?

Thanks

[Fran Guidry]

If your material has good sound attenuation properties I think you'll notice a benefit from this approach. I used two panels of OC703 and just leaned them against each other to form a V behind the mics and the difference was obvious and an improvement to my ears.

http://www.homebrewedmusic.com/2011/...adband-panels/

During that experiment I tried a third panel "roof" over the original two and noticed no improvement.

A Jdisk needs a solid core with sound damping on the surfaces.

Fran

[el_kabong]

Interestingly, the engineer I help just used this approach for a session with a client. We often work in an old wooden theater building that, depending on other things going on there, can be fairly lively.

For longer/bigger sessions, we usually employ a more comprehensive treatment, but for this recent solo solo session we just cobbled up some gobos as you described....basically office dividers with sonex acoustic foam attached. The singer was fairly well surrounded, but the greatest impact was achieved with the panel placed directly behind single mic used for the session...which was a Shure KSM-141 (if I remember correctly).

Here's a sample: https://dl-web.dropbox.com/get/Scooc...Q0sXHaK9Qi11qA

Oh, I can't remember if we hung something above this impromptu "enclosure", but I don't think so. Hope that helps.

[MikeBmusic]

Make them all 2' wide x 4' tall (that's the standard insulation size). If you've got 8' (or higher) ceilings, you can stack them two high, or lay them down lengthwise and stack them to three high. Use 1x4 (or 1x6 stripped down to 4" exactly) frames and stretch any 'sound-transparent' cloth over them (cotton-polyester sheeting is a good choice). I'd recommend not hinging them together as they will get pretty heavy and awkward this way. In the future if you get into a more permanent recording/mixing room, these become your corner bass traps.

[Fran Guidry]

I'm not sure about Roxul, but Owens Corning OC703 is rigid enough that no frame is needed. I basically just wrap mine in burlap. I still haven't figured out a _good_ way to do this, but I've come up with a few workable ways.

Fran

[ChuckS]

Originally Posted by MikeBmusic

......I'd recommend not hinging them together as they will get pretty heavy and awkward this way. In the future if you get into a more permanent recording/mixing room, these become your corner bass traps.

Originally Posted by Fran Guidry

I'm not sure about Roxul, but Owens Corning OC703 is rigid enough that no frame is needed. I basically just wrap mine in burlap. I still haven't figured out a _good_ way to do this, but I've come up with a few workable ways.

Fran

The Roxul Rockboard is somewhat rigid, but I was thinking of ripping a 1/2" thick sheet of plywood into 4" widths to use as frame material. For the 3 panels in the U shape I was thinking of using door hinges; that would allow me to take them apart easily.

There is a comparison of Owens Corning, Roxul, etc at this site:

http://www.atsacoustics.com/page--Se...erial--ac.html

The Roxul Rockboard 80 is much more dense than the OC703 and seems to have better low frequency attenuation.

[sdelsolray]

Originally Posted by Fran Guidry

If your material has good sound attenuation properties I think you'll notice a benefit from this approach. I used two panels of OC703 and just leaned them against each other to form a V behind the mics and the difference was obvious and an improvement to my ears.

http://www.homebrewedmusic.com/2011/...adband-panels/

During that experiment I tried a third panel "roof" over the original two and noticed no improvement.

A Jdisk needs a solid core with sound damping on the surfaces.

Fran

Of course, placement of panels depends on the particular room. Other folks could easily experience a different result - two panels behind the mics do less and one above does more, or one to each side yields X and one below on the floor yields Y.

[sdelsolray]

Originally Posted by ChuckS

I'm considering building a portable 'gobo' type of room treatment panel arrangement. I don't have a dedicated recording room, and sometimes record in different rooms, so it has to be something I can take down or move. I'm wondering if it is wise to try to build something to obtain a dry/dead space?

Here is what I was thinking of doing: for material I'm able to order in Roxul rockboard 80 from my local lumberyard; 4" total thickness. I was planning on (3) 6' high panels (one 3' wide and two 2' wide) and hinge them together into a U shape. Also thinking of having a panel to set over the top and a small one to use as a 'Jecklin disk'.

Is this a reasonably good way to get a portable treated space? Is this arrangement worth the time and money or should I consider something else?

Thanks

4' x 2' x 4" panels are fairly large. A 6' x 3' x 4" panel may be too large to a common studio space.

[alohachris]

Aloha Chuck,

Great advice from all so far.

My suggestions:

- Borrow or buy an SPL meter & identify exactly where the early reflections are in your room. Treat accordingly, the readings tell you where (& even what type) to place the treatment. The Pyle brand from Radio Shack works well.

- Start by building just two or four of Fran's 4"x2'x4'broadband absorbers using proven OC 703 not Roxul hardboard, IMO. Roxul is NOT used in professional studios. OC 703 or 705 is the standard. They come as 2"x2'x4's' (12 in a box of 2x2x4's). Use industrial spray contact cement outdoors (Loctite #200 or 300 is great) to glue two panels together. Use it also to wrap the cover. Use a cheap Walmart hot-melt glue gun to glue the material joints & corners up neatly. Use spray on anything that wasn't neat (Ha!)

- Do NOT frame them out. The hard frame surface defeats the purpose of treatment.

- Check out Fran's great DIY video's RE: DIY broadband absorbers. All of the materials you need are at Walmart (WHITE BURLAP is a more attractive cover than regular, Ha!) except the OC 703 which is not that expensive. Get that at an acoustic material outlet.

- Be prepared to make more gobo panels as needed. I started out with 9 & ended up with 22 broadband absorbers. I needed that many to treat both the room & the tracking space where I play/track - kinda of a "room or booth within the room" idea. It really works! I like to keep the floor wooden (no carpet) & 1-2 absorbers directly above where I play/track. I also trap the corners of the room with absorbers for bass freq's & even the wall-ceiling joints above the monitors for freq. separation.

Hint: You can "tune" a space by increasing or decreasing the number of absorbers used & the space between them. Sometimes, I want more of the live room in a mix, say for example, for a voice that's very bassy & all not that clear (like mine's becoming (Ha!).

- Portable is where it's at, Chuck. Good idea, really. I'm a renter in Hawaii. We move relatively often out here (HA!). Therefore, portable is the only way I can treat a great variety of spaces I must record in & move in to.

- Here's some detailed explanations for ya: the acoustic room treatment bible from Ethan Winer:

http://ethanwiner.com/acoustics.html

Treatment is definitely necessary for controlling your recording space. Do not save it for last. Portable & DIY is the way to go & will make the biggest difference in your recording quality. It will also allow you to experiment more with mic placement which you cannot do (effectively or fully) in a room full of early reflections, Chuck.

PS: I made my absorbers about 8 years ago (I was slow to learn about the huge sonic differences they make for recording). They still look great, hold together well, are light-weight, are cleanable & don't get that dirty & very are storable when I need the room for other functions. Do it, Chuck. Build some broadbands & treat that baby!

Good Luck, Chuck!

alohachris

PS: You can make panels whatever size you want by cutting the OC 703 w/ large scissors. I did that for treating the wall-ceiling joints & also for the bass traps all corners of the room. Please be advised that you MUST wear a mask & gloves & long sleeves when handling OC 703. In fact, you should make your broadband absorbers outdoors if you can. You don't want to breath that stuff which is why we cover it. After they're done, you can store them anywhere w/o worrying (the glue on the surfaces really seals in the fiberglass, Chuck) -alohachris-

[ChuckS]

I appreciate all the feedback and suggestions.

I'd like to ask a more general question (departing from the material and construction details). Is the concept of surrounding the mics (behind, sides, top, possibly floor) a reasonably good way to make a treated recording space within an untreated room? Will this basically take the room out of the equation and provide a 'dry' space? As I explained in my first post, I don't have a dedicated room and will sometimes use different rooms, so I'd like to be able to disassemble it and have it be movable. However, if this approach is flawed, I'd like to understand this before I put in the time/money for this. If I really need to do this differently, well then I guess that is what I have to do.

[KevWind]

Originally Posted by ChuckS

I appreciate all the feedback and suggestions.

I'd like to ask a more general question (departing from the material and construction details). Is the concept of surrounding the mics (behind, sides, top, possibly floor) a reasonably good way to make a treated recording space within an untreated room? Will this basically take the room out of the equation and provide a 'dry' space? As I explained in my first post, I don't have a dedicated room and will sometimes use different rooms, so I'd like to be able to disassemble it and have it be movable. However, if this approach is flawed, I'd like to understand this before I put in the time/money for this. If I really need to do this differently, well then I guess that is what I have to do.

In general Yes placing 4" absorbers around the recording position will help and IMO the order of importance is, #1 behind the mic's, #2 on the sides, #3 behind your position, #4 above less important but possibly if ceiling is low and highly reflective and floor probably least important.
This will definitely help tame room buildups particularly if you can stay away from the walls as much as possible, in other words not close to any wall.
Nothing will take the room out entirely other than an anechoic room. But yes it should help a great deal

[alohachris]

Aloha Chuck,

As is usually the case, I totally agree with what Kevin wrote (howzit Kevin!). In fact, I tested portable broadband absorbers & placement by placing them in hallways & making recordings. I was surprised by how much control they can provide, even in the most limited, small space. Experimentation will be the answer, Chuck, for how to treat a given space. Kevin's guide is a good place to start.

Again Chuck, put a meter on your spaces. Ethan Winer's bible explains the "why's." And yes, you can apply portable treatment to any space, once you know what the reflection issues are - and later, with experience, even if you don't know, you can guess & make it work every time. I've applied my DIY absorbers to some 15 rooms thus far & made it work. As Fran's great video demonstrated, as little as two panels can make a huge qualitative difference to your recordings, Chuck.

BTW, what type of treatment are you going with? DIY or store bought gobo's? What types of rooms will you use? What's your signal chain? What type of music do you wish to record? What are your goals for recording? Just curious.

Good Luck, Chuck!

alohachris

[MikeBmusic]

I went with the Roxul 80 for my traps - 6 of them in a small room, and I stuffed a lot of 'fluffy' fiberglass into the perimeter above my suspended ceiling. And I just added 2 3" Roxul Safe-and-Sound cloud panels and a couple of corner superchunks made from the S&S as well. The first bass traps made a world of difference, the additions are harder to quantify. Obviously the OC material has better low frequency absorbtion characteristics, so one must balance economy with performance. I've also been told that stuffing standard fiberglass insulation (the pink stuff) behind corner bass traps is good - you can even leave it in the original rolls if you have the space.

[ChuckS]

Originally Posted by alohachris

.....[snip]......
BTW, what type of treatment are you going with? DIY or store bought gobo's? What types of rooms will you use? What's your signal chain? What type of music do you wish to record? What are your goals for recording? Just curious.

I plan to go the DIY route; gives me more flexibility in size/materials and should be much cheaper. I don't have a dedicated music room; sometimes I'm on our 3 season porch (vaulted ceiling, wood ceiling and walls, lots of windows, carpet), sometimes in our DR/LR (8 foot ceiling, carpet), and sometimes in our basement rec room (8 foot ceiling, carpet).

I play steel string acoustic guitar; fingerstyle solo arrangements; no vocals. I have a pair of ADK A6's, and recently got a pair of 3 Zigma CHI mics, into a Focusrite Scarlett 6i6, and Reaper on a PC. I have Equator D5 monitors for mixing/playback.

As far as recording goals; this is just a hobby. I have no real use for my recordings other than for my own interest and to learn; I occasionally will post a song. I like to capture the sound of my guitars as realistically as possible; not just a good recorded sound, but their real character. I'm more into the guitars and playing than I am into recording, but over the years I keep getting a bit deeper into recording as well.

[MikeBmusic]

Originally Posted by ChuckS

I plan to go the DIY route; gives me more flexibility in size/materials and should be much cheaper. I don't have a dedicated music room; sometimes I'm on our 3 season porch (vaulted ceiling, wood ceiling and walls, lots of windows, carpet), sometimes in our DR/LR (8 foot ceiling, carpet), and sometimes in our basement rec room (8 foot ceiling, carpet).

I play steel string acoustic guitar; fingerstyle solo arrangements; no vocals. I have a pair of ADK A6's, and recently got a pair of 3 Zigma CHI mics, into a Focusrite Scarlett 6i6, and Reaper on a PC. I have Equator D5 monitors for mixing/playback.

As far as recording goals; this is just a hobby. I have no real use for my recordings other than for my own interest and to learn; I occasionally will post a song. I like to capture the sound of my guitars as realistically as possible; not just a good recorded sound, but their real character. I'm more into the guitars and playing than I am into recording, but over the years I keep getting a bit deeper into recording as well.

From your intended use, I think building some 2x4 traps (framed - easier to stack and move around) will work fine for you and you will notice much less 'room' in your recordings.