First Bass traps, help needed with layout and quantity

[urmasT]

Hello!

This is my very first post here, though I wanted to post here a long time ago. I plan to build bass traps for my room which has really bad acoustics. The worst problem is with bass at 80Hz, where the frequencies sound really loud. I plan to use rockwool for bass trap, and I thought to use a 4 inch rockwool panel. Is it enough or should I vary the thickness for better result?

Here are some pictures of my room. Measurements are in meters. I plan to build four bass traps in total, it is one to every corner, but how high they should be? All the way to the ceiling? Should I have at least one bass trap behind the sofa?

My subwoofer is firing to the floor.

Unfortunately I can't give links, because this is my first post, but if anybody is helpful, he can copy the link and look the pictures.

www(dot)upload(dot)ee/files/991587/Room_copy.png.html

www(dot)upload(dot)ee/files/991589/Room2.PNG.html

Thank you

Urmas

 

[jostenmeat]

Post some nonsense here several times:
http://forums.audioholics.com/forums/showthread.php?t=49318

Corners are indeed the best spots to tackle first. Google "superchunk bass traps". That essentially entails cutting of triangle pieces, stacking them floor to ceiling, covered in acoustically transparent material.

I totally understand if that's too much to handle, and otherwise straddling a corner with a 4" trap is still a good solution. Floor to ceiling can be argued to be best, because the more boundaries that meet, the more bass issues might be prevalent. So the top and bottom corners are where three boundaries meet . . .

While one might "deaden a room too much" with HF absorption, I have read that it is virtually impossible to go overkill with bass trapping.

As for quantity and layout, there are a couple of methods. The first of course is to use measuring equipment to know for sure. The second is to simply use your ears. Like with salt and pepper, just add to taste.

 

[urmasT]

Okei, here are some pictures, that I talked earlier.






As you can see, I have one corner ( where the right speaker is) with a lenght of about 12 inches. This means that I can't build really wide bass trap and put that under an angle of 45 degrees. I read about the superchunk bass traps and I think it requires to much rockwool. Maybe I could make ordinary bass traps to every corner ( from floor to ceiling) and then add 2 bass traps behind the speakers? How should I treat the floor firing subwoofer, should I hang some bass traps to the ceiling at that place? I actually don't know where are the first reflections of a subwoofer, because in my oppinion it's the floor that reflects first.. I plan to use carpet ( at the moment I have laminated floor), would this somehow also reduces the boomy effect?

Hello!

This is my very first post here, though I wanted to post here a long time ago. I plan to build bass traps for my room which has really bad acoustics. The worst problem is with bass at 80Hz, where the frequencies sound really loud. I plan to use rockwool for bass trap, and I thought to use a 4 inch rockwool panel. Is it enough or should I vary the thickness for better result?

Here are some pictures of my room. Measurements are in meters. I plan to build four bass traps in total, it is one to every corner, but how high they should be? All the way to the ceiling? Should I have at least one bass trap behind the sofa?

My subwoofer is firing to the floor.

Unfortunately I can't give links, because this is my first post, but if anybody is helpful, he can copy the link and look the pictures.

www(dot)upload(dot)ee/files/991587/Room_copy.png.html

www(dot)upload(dot)ee/files/991589/Room2.PNG.html

Thank you

Urmas

 

[jostenmeat]

As you can see, I have one corner ( where the right speaker is) with a lenght of about 12 inches. This means that I can't build really wide bass trap and put that under an angle of 45 degrees. I read about the superchunk bass traps and I think it requires to much rockwool.

Ah, yes, don't worry about it. It doesn't have to be 45 degrees if it doesn't fit. If you can only do say about 20 degrees, then so be it.

Maybe I could make ordinary bass traps to every corner ( from floor to ceiling) and then add 2 bass traps behind the speakers?

Yes, behind the speakers will reduce what is called SBIR. The closer your speaker is to the front wall, the more likely you would benefit from those.

However, if those diagrams are actually to scale, you now need to put the back wall at either the top or very close to the top of your priorities. Ideally, you would like to have at least a few/several feet from that wall, and if you cannot, it's time to start loading it with broadband absorption.

For this reason, if you are not loathe to block a large part of that side window, you might consider rotating the orientation 90 degrees, so that your new back wall is now far away. Also, it would make the overall response/energy more symmetrical, or less imbalanced.

If I was given just two corners to treat as it is right now, they would definitely be the rear left and front left. This will help tame the asymmetrical energy of the layout.

How should I treat the floor firing subwoofer, should I hang some bass traps to the ceiling at that place? I actually don't know where are the first reflections of a subwoofer, because in my oppinion it's the floor that reflects first.. I plan to use carpet ( at the moment I have laminated floor), would this somehow also reduces the boomy effect?

With subwoofers, the frequencies provided are much more omnidirectional. I would not worry at all about treating ceiling or floor for the subwoofer. Again, it will be the back wall and perhaps the two corners I've mentioned.

You can use something like the Auralex subdude or gramma if those are the right names, to help decouple your sub from the floor. Some think it's not necessary, and others think it's a no brainer upgrade.

Hope this helps.

 

[urmasT]

Thank you jonstenmeat for replies.

I have decided that I can't rotate my listening angle 90 degrees because then the sofa would stand in the walking path and I think other people in the room would not be very happy about that.

Corners: I plan to do make 4 superchunk bass traps, 3 of them have the longest sides of a triangle 56 cm ( 22 inches). 1 of them ( the one in the front right corner) has the longest side of a triangle 30 cm (12 inch).

Due to space problems the angle for all bass traps should be about 35-40 degrees.

Front wall I plan to make 2 panels behind each speaker. The panels are the same size as the Rockwool panel (120x56x10 cm).

Question: Should I put something to the corner above the speakers where front wall and ceiling meet?

Back wall Yes, the measurements of the drawing are correct and indeed my ears are pretty close to the back wall at the moment. I plan to attach one panel ( the same like on the front wall) behind me on the wall.

Question: Should I place one panel directly above me where ceiling and wall meet? If I should then it should also have the angle of 45 degrees?

Window I think I should make a portable panel that I can remove while I'm not listening to music. This should remove window reflections.

Material for panels: Rockwood 60kg/m3

For information, I don't have a good sound system, just an ordinary low-end stereo system and a Creative Megaworks 2.1 subwoofer. What I'm trying to do is to get maximum out of what I have right now and later invest ( if I have money) to the decent stereo system.

Any thoughts of what I should do differently are welcome.

 

[jostenmeat]

I wouldn't even worry about the front/right and rear/right corners, perhaps. Definitely not superchunk by any means, IMO. The bass waves can still wrap/diffract past that corner I imagine, and I just don't know if it's worth trapping for low bass there. We need an expert to chime in so that I don't misinform you any further.

My guess is that an expert would tell you that thicker panels, and more of them, behind the listener. Thick enough to absorb bass, as the bass will be collecting there. While more bass doesn't seem like a bad thing, the problem is that it may mask your other frequencies.

In all honesty, depending on what your speakers are, I'd take all of this budget towards new speakers. You seem to have a penchant for DIY, and if you were willing to build speakers, you could potentially find tremendous value.

Check out the ER18 build for instance in the DIY subforum. The silk dome version comes out to $551 for the pair as of several months ago, including even the spikes. But it doesn't include the wood and glue, which won't be too much. The speaker that it most closely resembles costs $4,200, by the same speaker designer (although it uses superior drivers, if still made by the same SEAS company). I throw out this idea, just in case, depending on your current speakers. I suppose the problem is what you can find in Estonia (I've driven through your country once, heh), however I am sure there must be some good European DIY resources. If this sounds interesting, I cannot think of a better person to ask than TLS Guy as far as European DIY resources are concerned.

 

[urmasT]

Thanks for reply. I made some recalculations and gave up the superchunk bass trap idea. Instead of that I went the easier and cheaper way.

Here are some pictures of what I did:
http://utiirik.wordpress.com/2011/01/03/bass-traps/

Yes, you are right, I definitely have to start looking for a better system.

 

[jostenmeat]

Thanks for the pics, and the mini! I had to look up susurrus.

Personally, I'd get new speakers before amp/processor, just going by the looks.

Congrats.

 

[son-yah-tive]

Nice JOB! And a GREAT idea.