Acoustic Room Treatment

http://www.acoustimac.com/index.php?page=shop.browse&category_id=11&option=com_virtuemart&Itemid=21

http://www.readyacoustics.com/index.php?main_page=index&cPath=26_11

http://www.atsacoustics.com/cat--DIY-Acoustic-Materials--102.html

http://www.mcmaster.com/

http://www.gikacoustics.com/products.html

http://moverssupplies.com/MOVING-BLANKET/BW-Cotton-Blanket-Producers-Choice/

http://www.markertek.com/CatList.asp?cat=ACOUSTICS&subcat=&prodClass=&search=0&off=0

http://www.readyacoustics.com/

http://mixonline.com/design/products/audio_turnkey_acoustic_treatment/

http://www.theprojectstudiohandbook.com/articles15.htm

http://www.thefoamfactory.com/acousticfoam/acousticfoam.html

yep, that's the way.

get your bass traps working first...

then, spot treat for high end.

check out those links, in some of them, there are guidelines or links to info about optimum room setups.

Just looked at [link=http://www.thefoamfactory.com/acousticfoam/acousticfoam.html]http://www.thefoamfactory...foam/acousticfoam.html[/link]

Their prices are much better than anything I've found in the UK!

Seriously don't waste your money on foam. DIY it. Rigid fibreglass or semi-rigid fibreglass it what you want to find. Go down to your local hardware store and ask them about it. If they don't have a clue, call up your main insulation companies and ask them about it. You are looking for a density of at least 48kg/m^3. This is the density of OC703. You can also use the 96kg/m^3 desnity if you want, that's equivalent to OC705. Anywhere in that density range will do it. Shop around, get a good price, find out what sizes you can get it in, then move on to the next stage..

So, bass traps are what you need first. Forget everything else for now. Bass traps. Bass traps. Bass traps. Tri-corners are the most effective points usually. If you have the money, treat every corner - wall to floor corner, wall to wall to floor corner, wall to wall corner, ceiling to wall corner, ceiling to wall to wall corner, etc. If you go that far, you're going to get some serious high freq attenuation. We'll discuss that one soon.

Building. Very simple, work out the sizes you want to make your panels (make rectangle panels, forget making triangle panels) and make a simple wooden frame of that size, and reinforce it. How thick to layer your rigid fibreglass? Probabaly about 150mm thick IF and only if you have the money to treat all the corners at this thickness. If not, then make it 100mm thick and treat all the corners. The order of importance here is: treat all corners first, then make panels as thick a possible. Now get some nice cloth and staple it onto your frame, wrapping everything up nice a neat. Something breathable, but not too breathable so particles get out.

Now, if you make a lot of these, high freq could be too attenuated. What can you do? One suggestion is to put a layer of aluminium foil on the outside of your panel, glue it to the fibreglass, then put your cloth over the top. Doesn't hurt the low freq, but gives it a little more livliness.

Why not fill the corners completely with a triangled shapped trap? You can if you want to, and it will work better, BUT, it's a waste of money. Attenuation occurs when the sound wave particles are moving at maximum velocity THROUGH the panel. A standing wave has a particule velocity of ZERO directly on the wall. As you move away from the wall, velocity increases to a maximum, then it decreases again, then increases, etc. You can measure this if you want to get serious, but don't worry about it. Just space the panels a bit away from the wall and they'll get the waves at their max velocity near enough. Fill the air gap up if you want to, but it won't do much (will do something though). Better off spending your money on making the panel thicker, or more panels.

So, we now have lots of panels in bass trap positions. Oh and don't waste your time putting a backing board on the panel (like the mdf you suggested). I mean, you could tune this board so that it resonates with the standing waves and then tries to dissipate the waves and blah blah, but for a diy job, forget it. It's going to potentially create small standing waves at other frequencies which might and might not be a bad thing (more standing waves at different frequencies can cancel each other out and give a flatter response, studios work on this principle with the angled walls). It just gets too tricky.

So, bass is now sounding tighter? Good. Next, flutter echoes. Got any? Yes? Ok, two things you can do, diffuse or absorb. Put a diffuser on one of the reflecting walls, or an absorber. A bookcase will work well as a diffuser. All dealt with now? Good.

So, how is the stereo image? Blurred? As has alread been mentioned, absorption at the reflection points. Imagine your room was a mirror and wherever you can see your monitors in that mirror (from the first reflection ONLY, not from two mirror reflections) place an obsorber there. This can very noticably tighen up your stereo image. But don't put too much or your room will get too dead in the high end, and we know what happens then. Idealy you want a decay that is quick, and even in all ffrequencies. Don't want the bass ringing out over 1000ms while the highs are gone in 50ms. We want them to be much closer together. And short, but not too short, cause then it's too unnatural.

And that's it. Everywhere that doesn't have an absorber, put a diffuser. They are great. Well not everywhere, but break it up nicely.

BIABDude


++++++1 on
http://www.readyacoustics.com/index.php?main_page=index&cPath=26_11

Or build your own out of wood for a tenth of the cost...

If you're making a professional studio this could be great, but a home studio, it's a waste of money.

Wow, thanks to all for their suggestions - if I go down the DIY route then I'll be sure and post some pictures.

@ Matt - special thanks for taking the time to write such an informative post.

@BIABDude - alas! US again some interesting products though.

@Jonesy - helpful as ever mate!

yeah, rockwool for bass control....

2" angled foam for high mid-high end control, and then, only spots.

you probably don't really need a whole lot, the bass traps will be the most important part of the process.

those ready acoustics chameleon frames look really nice, for that professional finished look.

i agree with matt, if it's not a commercial venture, you could probably build nice frames with nice wood yourself, and finish them with a nice tinted finish, and call it good.

lots of good posts here, you gotta eat it all, puke it back, and see what it looks like.

Bristol_Jonesey


This stuff is pretty good Jamie:

http://www.wickes.co.uk/Heavy-Density-Insulation/invt/161189

Bristol_Jonesey...I was considering this. Can I ask what this material actually is?


Thanks

Zipps

I've seen several cheaper and easier to handle alternatives to the heavy density one mentioned by Jonesy

For sidewall absorbers and ceiling clouds, high-density is not as important. But for bass traps, the heavier the better.

When considering a product, look at the pounds-per-square-inch value. 703 is fine for clouds at 3lb, but 705 is better for corner traps at 6lb. There are even 7lb and 8lb versions. If you can't find the heavy stuff, just double up the lighter products - 4 inches of 703 is equivalent to 2 inches of 705 for example. And you don't have to have 4" thicknesses, either. If 1" material is all you can find, just use 4 layers of it. Just remember, it's the total mass (volume * weight) that determines how much sound energy will be absorbed.

In the UK you have home-improvement store chains like we have here in the US (e.g. Home Depot). Although they are geared toward the handy homeowner and probably don't stock exotic insulation products, my experience is that they can special-order pretty much anything. Of course, they won't have a clue what you are talking about, but if you give them a specific manufacturer and product model number they shouldn't have any problem ordering it for you.

GIK was the way I went for bass traps. Inexpensive and you can just hang them on the wall as they come out of the box. Great people to deal with as well.

tcm123


can you not get oc703 and oc705 on the east side of the atlantic?

Hi tcm123

Oh yeah...we can get oc703 over here in the UK. I live very close to the stockist Bristol_Jonesey gave for the high density stuff. If this stuff is 703 then this would save me having to wait for a delivery and allow me to have a 5 minute drive to buy it.

Zipps

bitflipper


 Now, if you want to make your traps 24" deep or more, then you'll see significant improvement.

I still want to be able to get in the room Bit

zippsinc

Bristol_Jonesey


This stuff is pretty good Jamie:

http://www.wickes.co.uk/Heavy-Density-Insulation/invt/161189

Bristol_Jonesey...I was considering this. Can I ask what this material actually is?


Thanks

Zipps

It's a rigid fibre glass, similar I believe to what our American cousins call 703
 
If you do plan on using it, once it's in your frame, spray the front & back with a can of hairspray (1 large can per panel) to seal in the fibres, then cover with material.
 
 

Bristol_Jonesey


It's a rigid fibre glass, similar I believe to what our American cousins call 703
 
If you do plan on using it, once it's in your frame, spray the front & back with a can of hairspray (1 large can per panel) to seal in the fibres, then cover with material.
 
 

Cheers Bristol_Jonesey. I didn't expect hair spray to be in the equation...lol. Is this sealing of the fibers something generally considered wise from a safety point of view? Inhalation etc.

I think I read somewhere on another forum that rigid fiberglass is tomorrow's asbestos - in relation to harmful breathable substances. Anyone else heard this?


Regards

Zipps