# Need advice for my corner traps!!



## Jon10 (Feb 25, 2013)

Yes another thread asking for advice!! Thank you for your time hehe... btw I'm french, so sorry if I'm not using the right words...

So, I got some 34" wide "office screens" to put in front of my corner traps (piling up mineral wool). I'm hesitating on 2 matters:

1- A:Making 34x24x24 triangles with my wool, and being able to cover only half of the height of the wall;
B:Making 24x17x17 triangles with my wool, and beign able to cover from floor to ceiling.

2- If I choose option B (which I tend to), I'll have an air gap inside of my trap (remember the 34" wide office screen?). I'm wondering if I'd better be pushing the wool against the wall, or against the office screen?? I tried to attach a picture in this, not sure if it's working... anyway, I hope you get the question! Oh it did work, view is from the top of the trap of course...



I'm really not sure of what would be better, any help appreciated!!! And don't judge my Paint skills haha!! Thanks


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## bpape (Sep 14, 2006)

i'd do the smaller triangles and use the divider flat across the front - as long as they don't have a layer of mass in them


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## Jon10 (Feb 25, 2013)

Thank you for your reply Bryan!! The office dividers have actually what feels like a "foam mattress" inside of it, about 1,5" thick. I have enough to cover from floor to ceiling. I'd guess best would be trying to avoid that the wool touches both the walls and the divider. Or it could be pushed against the divider like you said?

Here's a pic of the control room. I treated early reflections with 4" thick acoustic foam. The booth is actually just divided by some big thick fabric, so not much of reflections from there. Everything is symetrical from left to right, except at the back of the room. Oh and walls are made out of some flexible material (kinda like sonopan) that certainly help with the reflections, but it might be a bit too much absorbing high frequencies...

I took some measurments with the corners empty, and some with the dividers in the corner (without any wool behind it). Below are some pics from REW program (used U-MIK), I don't have left-right separated sadly and I'm not at the studio... 

First pic is 1/24db octave smoothed, other are not, sorry. Red line is corners empty, violet one is with dividers. Seems like it's doing a honest job even without wool behind it. I have that huge dip at 100hz that I really want to get rid of... so I'm really concerned if the 24x17x17 triangles will do the job that low. (slope of the dip starting at 60hz ouch...). By the way I don't have a sub, so response below 30hz is mostly unreliable. Speakers are Yamaha HS80M.

I really need to finish the traps in the weekend, got some urgent important mixing to do next week, so your wise advices will certainly help me feeling better with my choices Bryan!! Thanks a lot for your time.


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## Jon10 (Feb 25, 2013)

P.S. What is happening at 30Khz in the waterfall??


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## HopefulFred (Jan 20, 2011)

Jon10 said:


> P.S. What is happening at 30Khz?


Something you will never hear. Probably something in the electronics, but even if its in the speakers, your ears dont care.


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## bpape (Sep 14, 2006)

Take a long pin or needle and make sure you can poke it all the way through the divider. Most of them have some hard layer in the middle to help block sound which would make them not good straddling in front of absorption.

Bryan


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## Jon10 (Feb 25, 2013)

Oh I didn't think about that, thanks Bryan. I'll have to cut one divider anyway so I'll see what lies inside...

I ended up doing 34x24x24, from floor to ceiling.... I was too suspicious that the 24x17x17 would not absorb low enough and decided to make them worth the name "Super Chunk" hehe. Had to push back everything 1 week, but decided it was worth it.

Here's some pictures of the work in progress. I will take measurments this week, and finish the job next weekend.

Wrapped them in 0.35mm polyethylene for the asthmatics that we are...
 

1 half of the chunk, with slats to support 2nd pile. Temporary sltas on the side to hold in place.
 

Global view
 

Second pile and divider in place. Will fill the upper gap with remnant mineral wool and cover with divider part.
 


Will post measurments later this week. Any thoughts/advice are welcome!!


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## watson b (Feb 18, 2013)

Jon10 said:


> 1 half of the chunk, with slats to support 2nd pile. Temporary sltas on the side to hold in place.


I'm about to start my own superchunks with mineral wool and was curious whether the intermediate support was necessary. Just wondering whether the weight of the entire stack would compress the bottom too much?


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## Jon10 (Feb 25, 2013)

I wondered the same thing until I stack them. The bottom ones are really having a hard time with the load, my pile was theorically 4 feet high, but in reality it gave 3,5 feet because of the compression. 

I used Roxul Safe'N'Sound, which is a pretty fluffy material, but relatively heavy at the same time. And these are 34x24x24 triangles, maybe if they were smaller it would be less an issue...

I'd say make one half of your height and see how it reacts. But my own suggestion would still be: make one support


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## watson b (Feb 18, 2013)

I'm using the same material and the same size as you. Thanks.


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## Jon10 (Feb 25, 2013)

Arg Bryan, you were right!!! There's a thin membrane inside of the divider  Glad I didn't pay for them!

Should I try to find something specific like speaker grill cloth, or would regular 84x36 curtains do the job to cover these things??


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## bpape (Sep 14, 2006)

Curtains would be just fine.


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