Building acoustic treatment on a budget
« on: August 02, 2018, 12:19:11 AM »
I don't know if this is the right subforum, if not can a mod please move it to the right one?

Anyway, what is the best way to build acoustic treatment for a small space? I'm talking like small apartment bedrooms and stuff. Is it fiberglass insulation in a rectangular frame covered with a soft breathable fabric? Is it foam (I've heard foam is bad because it does a lot less than insulation making the cost to performance ratio terrible. Is building a small booth the best? I know moving blankets and other heavy blanketing can help as well.

Basically I want a cost effective acoustic treatment, bonus points if it is highly portable, because I may not have the space to build an actual booth unless it's like 5'x5'x7' or something but then it would probably sound boxy.


Brian Roth

Re: Building acoustic treatment on a budget
« Reply #1 on: August 02, 2018, 01:29:43 AM »
Owens Corning 703 in a frame.\


But, it won't prevent acoustic transmission of sound into the next door apartment.

Bri

Brian Roth Technical Services
Salina Kansas, home of the best vinyl on the planet!

http://www.BrianRoth.com
recordingservicesandsupply.com/
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store.acousticsounds.com

abbey road d enfer

Re: Building acoustic treatment on a budget
« Reply #2 on: August 02, 2018, 04:59:33 AM »
I don't know if this is the right subforum, if not can a mod please move it to the right one?
Well, we don't have a dedicated section for acoustic design, so I think the best is to move it to the Drawing board.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

abbey road d enfer

Re: Building acoustic treatment on a budget
« Reply #3 on: August 02, 2018, 05:32:56 AM »
Anyway, what is the best way to build acoustic treatment for a small space?
Well, it looks like you want to adress two different issues: insulation and treatment.
The latter is fairly easy; you can build acoustic screens ("gobos"), using the aforementioned fiberglass or foam - foam is not bad at all regarding treatment. It has the advantage of not needing covering (fiberglass needs to be covered, both for looks and for avoiding fibers in the atmosphere).
Insulation is a very different matter. Foam and fiberglass provide isolation only at higher frequencies (>1kHz). The big issue is low frequencies and you need three things: weight, mass, heaviness  :).

Quote
Is building a small booth the best? I know moving blankets and other heavy blanketing can help as well.
  Unless you're ready to spend a fortune in an active noise reduction system ($$$$$), or covering your walls, ceiling and floor with tons of concrete, lead or MLV (Mass Loaded Vinyl), the least constrained solution is building a booth. Because the booth walls are decoupled from the room walls, the combined efficiency is much better than doubling the walls. There is a set of rules that must be obeyed when building a booth: decoupling the floors by inserting elastic blocks, avoiding leaks, damp vibrations,... You can find construction tips on the internet.

Quote
  I may not have the space to build an actual booth unless it's like 5'x5'x7' or something but then it would probably sound boxy.
Boxyness comes from reflections. Adequate treatment can get rid of reflections pretty efficiently; just check the so-called "reflection filters", some are quite efficient.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

CurtZHP

Re: Building acoustic treatment on a budget
« Reply #4 on: August 02, 2018, 07:33:10 AM »
I got quite a bit of help from these folks....

http://www.johnlsayers.com/phpBB2/index.php

Electrons don't read schematics.

JohnRoberts

Re: Building acoustic treatment on a budget
« Reply #5 on: August 02, 2018, 10:17:46 AM »
When pursuing budget solutions be careful about flammability, I've seen recording spaces with cardboard egg crates stuck to the walls (last century).

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

joaquins

Re: Building acoustic treatment on a budget
« Reply #6 on: August 02, 2018, 11:45:25 AM »
To avoid standing waves in the crate you should make it's walls so they are not parallel, 3º deviation is good enough and not so bad to look at. This reduces drastically the boxiness of the box, and the LF effects of the small space. Using that and some treatment with foam or glass wool you can get a decent space.

You want the walls to be heavy, depending on the insulation level you want, but as a rule of thumb, for twice the weight 12dB attenuation. MDF is a good choice for cheap, easy to work and weight, using 10mm will give 12dB less attenuation than using 20mm. The walls must be sealed between each other and tightly screwed or supported to avoid any vibration.

Also, as said, you want the thing to be floating on your floor, an old trick was to use some old car tires to mount the thing on,  but any thick enough rubber would do. To check the effectiveness you need to be able to move a little bit the thing when fully loaded and it must do a few small bounces side to side, if it just returns to the original position you don't have enough rubber and the isolation isn't as good as it could be.

As said, for insulation is this or doing some serious work on walls, ceiling and floor, not very cheap or portable.

JS
If I don't know how it works, I prefer don't turn it on.

totoxraymond

Re: Building acoustic treatment on a budget
« Reply #7 on: August 02, 2018, 02:10:54 PM »
Hi,

For once i can share my experience on this forum. Happy me! ;D

If you're looking for acoustic isolation, there's no way to avoid doubling the walls with two layers of drywall. Put fiberglass or rockwool behind. It's very effective if done right.

In my cellar i mounted them on wooden fram. It's lot more complicated than steel but a little bit more effective. I measured more than 33dB gained of isolation (it wasn't completely finished at that point, but didn't measured after that). We're pmaying loud punk music every monday night in there and never had a complain from a neighbor.

Same principle applies to floor and ceiling. The big flaw in my studio is the floor, but it's already less than 2m height.

For acoustic treatment. I did two things:

For high frequency absorption, i made wooden frames with fiberglass and fabric as mentioned above. Very effective and quite cheap.

For low frequency absorption, i made some flat panel absorbers. Sam principle as above, but with a wooden diaphragm instead of fabric. Again, it's really effective, low Q and not very expensive if you make them yourself.

You should definitely check Ethan Winer's website. It's full of great info.

And you should read Master Handbook of Acoustics. It's a very good reference and there's a complete chapter about home and small studio acoustic treatment.

If needed i could post some photos.

Hope i could help,

Thomas


Mbira

Re: Building acoustic treatment on a budget
« Reply #8 on: August 02, 2018, 02:59:08 PM »
This guy is asking about portable solutions in an apartment where he may leave, so building new walls isn't an option. 

My recommendation is look in to DIY "superchunks".

0) Do a REW room analysis to see where you are at. 
0.5) research the best place to put your listening position and monitors for your room.
1) Put superchunks in each of your four wall corners if possible.
2) Create a "reflection free zone (RFZ)" by putting 2x4' 4" thick OC703 panels in the places where you can sit in your sweet spot and see the cones of your speakers with a mirror against the side walls.
3)  Build a "cloud" above your listening position in the same way. 
4) do the back wall teh same way with the mirror trick. 
5) Cover the remaining 50% of the walls with more 2x4 panels. 
6) do a REW room analysis to see where you are at. 

Obviously, this is just a down and dirty list, but this gives you an idea of what you should expect to do.  Good luck!
Joel Laviolette

Rattletree   |  https://www.rattletree.com
The Rattletree School of Marimba | https://www.learnmarimba.com

totoxraymond

Re: Building acoustic treatment on a budget
« Reply #9 on: August 02, 2018, 03:06:07 PM »
Well, insulation wouldn't be portable. But acoustic treatment the way I did IS.

Just some 120*60cm modules that you can easily fix to walls in different ways. The day i move from my place, i'll take all with me.

Thomas


abbey road d enfer

Re: Building acoustic treatment on a budget
« Reply #10 on: August 02, 2018, 04:15:39 PM »
Well, insulation wouldn't be portable. But acoustic treatment the way I did IS.
A booth provides both insulation and treatment, and is removable/reusable.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Gold

Re: Building acoustic treatment on a budget
« Reply #11 on: August 02, 2018, 04:38:12 PM »
I’d recommend isolating the speakers from the structure as much as possible. Much of the sound transmission comes from  direct transmission of vibration .

Assuming you are using smallish near field speakers I have an easy and cheap speaker stand design.

Get two buckets and fill them with sand. Take 4” PVC pipe cut to the speaker height you want and stick them in the buckets of sand. Make sure the pipe doesn’t touch the bottom of the bucket. 

Then take  a short length of smaller 3” pipe and attach it to a flat platform to rest the speaker on. Fill the rest of the long pipe with sand. Push the top piece of 3” pipe with the platform into the 4” pipe. Done. It works very well.

totoxraymond

Re: Building acoustic treatment on a budget
« Reply #12 on: August 02, 2018, 04:52:40 PM »
Well of course. It depends on your needs, but most booth are not "budget". (at least according to my purse  ;) )

Here are a few pics of what I did :

Control room: it's abotu 9 m^2 (squarred meters) by  2m high, so VERY small...

I put 6 Flat panel absorber (front corners and behind listening position) and 4 Mid/High absorbers (2 top, and 2 sides aiming at first reflection). Please don't look at my mess...  ::)



hergeur d image

And my studio. It's about16m^2 by 2m high. I've recorded 3 discs in this room, before and after treatment, and it's like Night and Day... I've put as many absorbers as i could, alternating between Flat panels for Low and High/mid absorbers.



Here's a pic of a Flat Panel Absorber:
It consists of a box of wood 120*60*10cm  filled with rockwool (leave 2 cm of air between diaphragm and wool to let it vibrates)



And what i call High/mid absorber. Tha very famous concept of wooden frame filled with glassfiber, coated with fabric.



to fix it flush on the wall: very easy, there's a rail on the wall and those 2 shaped metal things on the back of absorber.
If you have enough room, leave some space between absorbers and wall. Much more efficient, and better in low frequency.



Finally, here are 2 measurements of my control room: (i might make more in the future, but don't have time for now)

First one is without any absorption. Notice the big 40db differential around 200Hz. that was getting me mad at the time.



And now with the 6 flat panel absorbers (no High/mid treatment).



The room isn't perfect for sure, but much better. With High/mid absorption at first reflection points, I gained a much better stereo image. And with all that, now i can move my head a few cm and here quite the same thing (before it was dramatically different).

All this treatment cost me about 500€ in France, so it's definitely budget. And it doesn't require many tools to build.

Thomas.

P.S: i just hope this can help somebody, I've learned so much from this forum and I have so few to give... :)

CurtZHP

Re: Building acoustic treatment on a budget
« Reply #13 on: August 03, 2018, 06:16:56 PM »
When pursuing budget solutions be careful about flammability.

JR


You just take all the fun out of everything!
Electrons don't read schematics.

Gold

Re: Building acoustic treatment on a budget
« Reply #14 on: August 03, 2018, 07:03:26 PM »
If the fabric you are using isn’t fire rated you can coat it with a chemical.  It’s sold at theater supply houses. There is one type for synthetic fabrics and another for natural fiber. It makes any fabric meet fire code in NYC.

JohnRoberts

Re: Building acoustic treatment on a budget
« Reply #15 on: August 03, 2018, 07:27:12 PM »

You just take all the fun out of everything!
Just trying to keep forum members alive.

I friend of mine owns  a company selling sound treatment (Real Traps) and has written extensively on the subject.

http://ethanwiner.com/acoustics.html

His website is even translated into a few different languages.

Even if you don't want to listen to me, listen to Mr Winer about acoustics, and more. (it feels funny calling him Mr. Winer :o ).

JR

PS: The cardboard egg crates I mentioned were in one of his old recording spaces many decades ago...but that whole place was a fire trap (old barn).
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Re: Building acoustic treatment on a budget
« Reply #16 on: August 04, 2018, 01:10:37 AM »
I feel like I should clarify that my apartment is more of a townhouse deal, so there's a basement with concrete walls, my bedroom is just small due to the way the rooms are built. This isn't my permanent living situation either (just saving up money so I can actually support myself without living completely paycheque to paycheque, don't live alone atm), so portable options are always welcome. Could a booth made of MDF and dry wall be good if there's insulation or thick foam inside the walls of it? That's what I'd like to do, but my ceilings are pretty low, so I could probably only have a max height of 7' (I'm actually kind of short at a bit over 5'7"), but space might be an issue. If I have the space to build an actual booth (and save up the budget), I don't mid dismantling it to move it assuming the whole thing doesn't get messed up.
« Last Edit: August 04, 2018, 01:16:19 AM by Icantthinkofaname »

abbey road d enfer

Re: Building acoustic treatment on a budget
« Reply #17 on: August 04, 2018, 01:50:58 AM »
Could a booth made of MDF and dry wall be good if there's insulation or thick foam inside the walls of it?
Drywall is efficient for insulation (because heavy) but cannot be dismantled and reassembled. MDF is a little less efficient and more robust, but quite expensive compared to chipboard.

Quote
  That's what I'd like to do, but my ceilings are pretty low, so I could probably only have a max height of 7' (I'm actually kind of short at a bit over 5'7"), but space might be an issue.
It all depends on what you intend to do. Is it just a vocal booth? You would have problems recording a Marshall triple-stack or a souzaphone  ;)
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Re: Building acoustic treatment on a budget
« Reply #18 on: August 04, 2018, 01:52:16 AM »
Just trying to keep forum members alive.

I friend of mine owns  a company selling sound treatment (Real Traps) and has written extensively on the subject.

http://ethanwiner.com/acoustics.html

His website is even translated into a few different languages.

Even if you don't want to listen to me, listen to Mr Winer about acoustics, and more. (it feels funny calling him Mr. Winer :o ).

JR

PS: The cardboard egg crates I mentioned were in one of his old recording spaces many decades ago...but that whole place was a fire trap (old barn).
So looking at the NRC chsrt, 703 fiberglass seems like the best overall, though the 705 has better absorption at really low frequencies?

Foam seems like the most convenient though. Relative to amount needed, which is cheaper? I've heard the fiberglass, because proper acoustic foam gets expensive and the cheap stuff you see online (eBay, sometime Amazon?, basically that crap that's $2 per square online) is actually thinner (both in thickness and density) and is actually rebranded packaging foam.

Do egg crates actually work? I've heard varying opinions (and honestly I'd rather not start hoarding egg crates) ranging from that they're good, only work for 1000 Khz or so, or they do nothing. I guess people just don't recommend them since you can order foam now. My real question is: is cardboard too hard to be useful, or does the shape of egg crates help diffuse the reflections? Not interested in using them unless I use them as a temporary solution.

Re: Building acoustic treatment on a budget
« Reply #19 on: August 04, 2018, 01:53:50 AM »
Drywall is efficient for insulation (because heavy) but cannot be dismantled and reassembled. MDF is a little less efficient and more robust, but quite expensive compared to chipboard.
 It all depends on what you intend to do. Is it just a vocal booth? You would have problems recording a Marshall triple-stack or a souzaphone  ;)
It'd just be a vocal booth for voiceover type recording, maybe foley recording.

Chip board being particleboard? If so how would that fare? I don't need 100% isolation either (so this likely won't be an airtight booth, I really just need to cut down on reflections with drowning out some outside noise, things like fans, refrigerator noise, light hum, etc. (Though the more noise drowned out the better).

As far as just reducing reflections, I've heard moving blankets work, though don't provide any real isolation. Anybody with experience using them (good or bad!) can chime in.
« Last Edit: August 04, 2018, 02:05:05 AM by Icantthinkofaname »


 

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