Excellent article about small room acoustics
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Soundlurker
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I got my subwoofer today and did some tests with a measurement mic and roomeq. My low-end response looks like an M with the first peak being over 10db at 36hz, then an 8db null around 60hz and an 8db peak at 85hz. The waterfall diagram shows a ton of ringing at 36hz (almost 600ms) while the rest of the spectrum sits around 100-150ms. Once I recover financially and get rid of some stuff from the room I'll add more broadband absorbers and I'll also target that nasty 36hz peak. I'll post some before/after comparisons once I'm done.
Edit: I forgot to mention my room isn't way too small (W L H = 3,5 X 4,5 X 2,5)but the building has thick conrete walls, hence the resonanse at 36hz.
Edit: I forgot to mention my room isn't way too small (W L H = 3,5 X 4,5 X 2,5)but the building has thick conrete walls, hence the resonanse at 36hz.
Hey man, I'm not sure any broadband absorbers are effective down to 36hz unless you make them insanely thick. Your best bet there would be to tame that peak a bit with EQ and focus your broadbands on the issues higher in the spectrum.
Melodeath
Moonbow
John_C
formerly Skeksis268
dont' tame ringing with eq. It just isn't the right tool, it might help a bit but it's not really adressing the problem
Soundlurker
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Yeah, I know. That's why I said "and I'll also target". I haven't decided how, yet. As a temporary measure I did use my interface's DSP eq to tame the peaks, but skeksis268 is right. I have to find a better way to adress the problem.
Here's a comparison
Before:
After:
Before:
After:
::XeS::
Member
I did some measurements today and I post the result.
My friend downloaded the sonar project they used in the article posted and he sent to me the wav file. I imported it in PT and I put a measurement mic in my listening position. My room is not treated at all.
You can notice there are several peaks and holes. The loudest peakes are at 110Hz, 140Hz and 180Hz, there are 2 big nulls at 90-100Hz, 160Hz and an extreme one at 260-280Hz.
It's very usefull to run this test because when you listen the reference track in real time, you can notice where you hear too much and where you don't hear. In some ranges you can clearly hear the frequency that augment every second, in some other ranges you hear absolutelly nothing.
If you wanna test your own room with the same reference track, this is the wav file: http://dl.getdropbox.com/u/1436721/response.wav (I'm uploading right now, give it some minutes)
My friend downloaded the sonar project they used in the article posted and he sent to me the wav file. I imported it in PT and I put a measurement mic in my listening position. My room is not treated at all.
You can notice there are several peaks and holes. The loudest peakes are at 110Hz, 140Hz and 180Hz, there are 2 big nulls at 90-100Hz, 160Hz and an extreme one at 260-280Hz.
It's very usefull to run this test because when you listen the reference track in real time, you can notice where you hear too much and where you don't hear. In some ranges you can clearly hear the frequency that augment every second, in some other ranges you hear absolutelly nothing.
If you wanna test your own room with the same reference track, this is the wav file: http://dl.getdropbox.com/u/1436721/response.wav (I'm uploading right now, give it some minutes)
Nice work guys.
Just to clarify: I wasn't suggesting to use EQ to tame modal ringing in place of treatment. I'm just stating that a broadband bass trap that effectively absorbs down to 36hz would have to be massive, or tuned specifically (also massive). This is where EQ can really help, since you have trouble attenuating those peaks physically, you can at least reduce their severity with EQ, taking into account of course that EQ doesn't reduce the length of ringing. So it's a stop-gap solution when nothing else is practical.
For those of you who want an easier to digest format of that article, there is a video on the real traps site that deals with the same issues. http://www.realtraps.com/video_wave.htm
There are a bunch of videos on the site which deal with a lot of acoustic issues. Very cool and very worth watching for everyone!
Just to clarify: I wasn't suggesting to use EQ to tame modal ringing in place of treatment. I'm just stating that a broadband bass trap that effectively absorbs down to 36hz would have to be massive, or tuned specifically (also massive). This is where EQ can really help, since you have trouble attenuating those peaks physically, you can at least reduce their severity with EQ, taking into account of course that EQ doesn't reduce the length of ringing. So it's a stop-gap solution when nothing else is practical.
For those of you who want an easier to digest format of that article, there is a video on the real traps site that deals with the same issues. http://www.realtraps.com/video_wave.htm
There are a bunch of videos on the site which deal with a lot of acoustic issues. Very cool and very worth watching for everyone!
::XeS::
Member
Yes the videos on that site are really interesting...I watched them some months ago.
Eq is not the solution for these problems of course.... Bass traps are one of the solution.
Eq is not the solution for these problems of course.... Bass traps are one of the solution.
Nebulous
Daniel
Does anyone know the density of this, or have a page that shows similar specs as this one does?
http://www.bradfordinsulation.com.au/Products/Commerical/Acoustic-insulation/Rockwool-partition.aspx
Trying to plan this shit for my house now so I know what I'm doing when it's done.
Nebulous
Daniel
ERMZ-
check this shit out: http://www.bradfordinsulation.com.a...stic-insulation/Bradford-Acoustic-Baffle.aspx
Ignore the picture up top showing the fiberglass shit, read the stuff below the heading Rockwool Acoustic Baffle and click on the datasheet PDF to the right. The residential rockwool offered by CSR has a density of 30-40 kg/cubed m. The stuff in the link is 60.
Otherwise, I'm sure his shit would cost an arm and a leg, but it's density is 110:
http://www.bradfordinsulation.com.au/Products/Industrial/Fibretex/Fibretex-820.aspx
What's the best you've found so far? What spec are you looking at reaching? Am I even looking at the appropriate spec?
check this shit out: http://www.bradfordinsulation.com.a...stic-insulation/Bradford-Acoustic-Baffle.aspx
Ignore the picture up top showing the fiberglass shit, read the stuff below the heading Rockwool Acoustic Baffle and click on the datasheet PDF to the right. The residential rockwool offered by CSR has a density of 30-40 kg/cubed m. The stuff in the link is 60.
Otherwise, I'm sure his shit would cost an arm and a leg, but it's density is 110:
http://www.bradfordinsulation.com.au/Products/Industrial/Fibretex/Fibretex-820.aspx
What's the best you've found so far? What spec are you looking at reaching? Am I even looking at the appropriate spec?
The best shit I've found is Tontine Acoustisorb 3. It's 48kg/m3 (the density of OC703). It's also polyester based so won't fuck your shit up if you touch it.
The company have been right CUNTS to deal with though. 3 weeks and no response, and then I get told 'oh no, we don't sell to the public' even though I'm purchasing as a business. So yeah, I've yet to find a place that stocks it.
http://www.insulationaustralia.com.au/ is my next try.
Specs are hard. Ideally you want something higher than 36kg/m3, but it depends. The noise reduction coefficient figures are the best idea you'll get, and even those vary from lab to lab. You just have to get advice from people who've done it, and pray you're going about it the right way.
The company have been right CUNTS to deal with though. 3 weeks and no response, and then I get told 'oh no, we don't sell to the public' even though I'm purchasing as a business. So yeah, I've yet to find a place that stocks it.
http://www.insulationaustralia.com.au/ is my next try.
Specs are hard. Ideally you want something higher than 36kg/m3, but it depends. The noise reduction coefficient figures are the best idea you'll get, and even those vary from lab to lab. You just have to get advice from people who've done it, and pray you're going about it the right way.
Nebulous
Daniel
Check out the CRS stuff then dude. If 48kg is what CO703 is, then you could even go with some of CRS/ Bradford's commercial stuff which goes up to 60kg. There are CRS/ Gyprock outlets all over town which should be able to hook you up. That's why I started looking at their products on the net, I pass about 2 outlets on the way to work and have another around the corner from my place.
Also, with superchunking, I'll be reading the Sayers forum from now on, but in a nutshell, is there an ideal or minimum depth that you should aim for, or do you just cut the rockwool into squares the width that they come in (480mm) and then cut triangles out of that?
Given that the rockwool sheets are like 50mm, you'd be using a fair amount of the more-expensive-than-oil material! You'd hope it would work.
Also, with superchunking, I'll be reading the Sayers forum from now on, but in a nutshell, is there an ideal or minimum depth that you should aim for, or do you just cut the rockwool into squares the width that they come in (480mm) and then cut triangles out of that?
Given that the rockwool sheets are like 50mm, you'd be using a fair amount of the more-expensive-than-oil material! You'd hope it would work.
With superchunks it's usually whatever is practical dimension and cost wise from the panels you get. Usually you get two options, depending on how many times you cut the panels, whether you want smaller or larger triangles. Factor in your costs, room size and neuroticness and there you go. I'm planning mine to be 600mmx600mmx850mm. So basically 60 centimeter squares cut in half.
The Bradford shit gets really expensive up in their top end. Back when I was looking heavily, the stuff they recommended for use in studios, and as their 'equivalent' to Owens Corning was the Fibretex 350: http://www.bradfordinsulation.com.a...s/f5/f52c2fc6-6c62-4dca-aa6e-c36f18d60b4a.pdf
I would prefer the tontine though because I can just stack it and leave the shit exposed and not worry about the fibers fucking me up or getting caught in my clothes or whatever. So I'm intent to go down that route. If it doesn't work out, well I'll be back with denser shit....
Having said that though, superchunks benefit from not being too dense. If you're using shit near 100kg/m3 you may actually start getting reflections bouncing back from something as dense as superchunks, so be wary!
The Bradford shit gets really expensive up in their top end. Back when I was looking heavily, the stuff they recommended for use in studios, and as their 'equivalent' to Owens Corning was the Fibretex 350: http://www.bradfordinsulation.com.a...s/f5/f52c2fc6-6c62-4dca-aa6e-c36f18d60b4a.pdf
I would prefer the tontine though because I can just stack it and leave the shit exposed and not worry about the fibers fucking me up or getting caught in my clothes or whatever. So I'm intent to go down that route. If it doesn't work out, well I'll be back with denser shit....
Having said that though, superchunks benefit from not being too dense. If you're using shit near 100kg/m3 you may actually start getting reflections bouncing back from something as dense as superchunks, so be wary!
Nebulous
Daniel
Haha! Good point about the density there.
I don't know if I would even consider going with the Fibertex stuff. Given that it's in their industrial range I would wander if it wouldn't be overkill in the price vs application, especially since they offer commercial grade material with the same densities and in their industrial range I seem to notice more of a focus on the heat shielding character rather than acoustic properties. They may have been pulling your hip pocket there.
Did you ever ask Indent Dave what stuff he used?
I don't know if I would even consider going with the Fibertex stuff. Given that it's in their industrial range I would wander if it wouldn't be overkill in the price vs application, especially since they offer commercial grade material with the same densities and in their industrial range I seem to notice more of a focus on the heat shielding character rather than acoustic properties. They may have been pulling your hip pocket there.
Did you ever ask Indent Dave what stuff he used?
Nebulous
Daniel
Also, what spec was the stuff you currently have in your room? Do you remember how much it cost?
I've just worked out that for my new place, for the one room I will need about 40 rockwool sheets for all the (basic) stuff I'm planning. I'm sure that will even get up to the 50 mark by the time I do some more research.
I've just worked out that for my new place, for the one room I will need about 40 rockwool sheets for all the (basic) stuff I'm planning. I'm sure that will even get up to the 50 mark by the time I do some more research.
Ok the Tontine 2400x1200x50mm panels come in packs of 3, and each pack costs $180 bucks. 3 packs needed to cover superchunking 3 of my corners here. All up with delivery should be just over $600. Pretty good!
The stuff I have in here now is called Bradford Soundscreen. It's about 32kg/m3 I think. Not dense enough. I really made a mistake on that, but I had nothing to guide me when I was looking, so it was a bit of a clusterfuck. The cost was next to nothing, but so is the performance.
Are you talking acoustic isolation or treatment?
The stuff I have in here now is called Bradford Soundscreen. It's about 32kg/m3 I think. Not dense enough. I really made a mistake on that, but I had nothing to guide me when I was looking, so it was a bit of a clusterfuck. The cost was next to nothing, but so is the performance.
Are you talking acoustic isolation or treatment?
Nebulous
Daniel
Yeah soundscreen is their residential crap. I wouldn't even think that would be enough for what we want it for.
The Tontine stuff seems ok, since each peice is quite large and would cover so much surface area. If I was to get the bradford Acoustic baffle I'd need almost 10 per corner!
At this point I will be getting my dedicated room fitted with rockwool in the walls, so I'm not particularly worried about isolation beyond that. If my father was building the house then I'd be able to go abit more crazy with that, but it will have to suffice.
The romm will be at the rear of the house, so I shouldn't expect too much traffic noise and the only time isolation may be a problem is if I want to really crank the shit out of the amp. Which I don't do often.
At this point I'm more concerned about having as much treatment as is practible in the space, while making sure that the treatment is working on the correct characteristics and is efficient. I know I won't get a 100% control room situation, but having something to be proud of and I can use long term to do more than I've been able to up untill now would be nice.
The Tontine stuff seems ok, since each peice is quite large and would cover so much surface area. If I was to get the bradford Acoustic baffle I'd need almost 10 per corner!
At this point I will be getting my dedicated room fitted with rockwool in the walls, so I'm not particularly worried about isolation beyond that. If my father was building the house then I'd be able to go abit more crazy with that, but it will have to suffice.
The romm will be at the rear of the house, so I shouldn't expect too much traffic noise and the only time isolation may be a problem is if I want to really crank the shit out of the amp. Which I don't do often.
At this point I'm more concerned about having as much treatment as is practible in the space, while making sure that the treatment is working on the correct characteristics and is efficient. I know I won't get a 100% control room situation, but having something to be proud of and I can use long term to do more than I've been able to up untill now would be nice.
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