|
Post by explorer on Apr 2, 2016 16:33:53 GMT
Dear Ethan and other participants, I am making some 30 m2 of "fake curtains" around my live studio room. It is not a final solution as I am aiming to get some real gathered acoustic curtains in a future. For this solution I made layers of several wool blankets with average density of 1000 g/m2. I am enclosing it in a fabric. The enclosing fabric I got is SELONYA AKFIL made in Turkey and is 100% cotton. portuguese.alibaba.com/product-free/selonya-akfil-126702579.htmlHowever, I noticed that while I still can breathe through it, it is very difficult. Much more difficult than through some other fabrics I came across in a past. To illustrate it better - if someone is forced to have it on their mouth and nose, the person will survive as breathing is possible, it is just very hard. So, it must be that density is much higher than other fabrics I came across so far. It is 130 g/m2. Would you recommend it for my purpose, or you would search for something "more breathable" ? How much impact this would have and on which freq. spectrum? Thank you! p.s. what happened with other (old?) forum... I had to register again and it looks different as far as I see...
|
|
|
Post by explorer on Apr 4, 2016 15:44:09 GMT
Update:
just wanted to add that I tried to blow and breathe through pair of jeans and it is impossible.
My fabric SELONYA compared to jeans is airy, breathable and as I said earlier, if someone forced you to have it on mouth and nose, you would be able to breathe and survive.
Breathing and blowing through SELONYA is possible but with certain resistance whereas other materials I used in past offer no resistance to breathing whatsoever.
Thats why this resistance scared me because I do not want to make mistake.
My hanged panels (fake curtains) are for mid highs and highs. They will be placed 30 cm apart from irregular stone walls.
If I would be making bass traps, I would fear no problem, but I just want to hear opinion on my current situation.
THX...
|
|
|
Post by Ethan Winer on Apr 4, 2016 16:43:20 GMT
The "blow through" test is mostly to ensure that a fabric is acoustically transparent. You need that for speaker grill cloth, or in front of diffusers. But fabric in front of absorbers doesn't have to be transparent - if it's thick and absorbent all by itself that's fine. Even if the fabric is slightly reflective at the very highest frequencies, that's not necessarily a bad thing either. But generally, when the goal is to absorb mids and highs, you do want something soft and breathable. One other exception I'll mention is if a room is very large, such as the length and width are 20-30 feet or more. In that case if the material doesn't absorb above 5 KHz fully, the air will absorb some just due to the longer distances. So there again, fabric that's slightly reflective is probably okay.
--Ethan
|
|
|
Post by explorer on Apr 4, 2016 17:51:08 GMT
thank you for the reply,
I guess my best bet is to try to change the fabric to something more "pass through" but if it wont work, maybe it is not disaster with the one I have now?
|
|
|
Post by David on Oct 29, 2016 6:43:21 GMT
So then for bass traps, a thick non breathable/non porous material such as polyester would be beneficial? And panels at reflective points, such as the side walls, ceiling, and directly behind would be better suited with porous material?
|
|
Trdat
Junior Member
Posts: 78
|
Post by Trdat on Oct 30, 2016 9:56:29 GMT
Hello Ethan and other participants, I apologize for perhaps repeating the question, though I am very curious about this topic. I have already made my panels and lot of hard work has gone in them. I have a massive, I mean massive reflection free zone 4 inch thick, I used mineral wool 100kg/m3 only available where I am. And the ceiling panel has a 20cm gap. Plus floor to ceiling bass traps at front of room.
In a nutshell, the fabric i used is mix of flax, some cotton and polyester its only half as soft as the fabric on an ATS panel of mine when compared and its only about half as breathable when i do the breathe test. Its fully stretched on the panel and the weave is not that dense. The previous post explained it well if you where forced with the fabric on your nose and mouth its breathable but very difficult so hence I understand that perhaps your answer will be along the same lines. Although I initially wanted a more lively room I never intended to purchase fabric such as the one I bought, it was the best choice between aesthetics and breath ability.
I can tell you that just from listening with the new panels I have up to 50% perhaps more in the quality of bass which is great achievement. This is without testing but I can feel the difference. But I cant hear much improvement with high frequencies cause it feels that the highs are not dampened enough but maybe that's a good thing like you said. Also I agree that it could be the direct sound from the tweeter that I am hearing so clearly that could be the impression I get that the highs are still to much.
My question is simply with the above information including the mineral wool(as I have heard that the dense mineral wool reflects some highs) I used, do you think that I went wrong and need to think of something to absorb those first reflection points with something else? Or the difference would be so minimal that there is no point worrying about it? Essentially if my DIY are legit than I'm looking at excessive liveliness from the rest of room, if that is the case then I can work on that as my next project.
PS. I know it takes a while for ears to get used to sound.
|
|
|
Post by Ethan Winer on Oct 30, 2016 18:42:13 GMT
You can tell how well a material absorbs or reflects high frequencies by talking into it, as shown in this short video: www.youtube.com/watch?v=iAFsDE2uAZQIf you question the panels you made, try the "talk test" using good quality foam or any other absorber that you know is effective at high frequencies. Then compare that to your own panels.
|
|
Trdat
Junior Member
Posts: 78
|
Post by Trdat on Oct 31, 2016 9:08:08 GMT
Great test. I can definitely hear the difference and I would say its reflecting some highs, but not much. And its hard to say if its cause for concern.
Would placing foam panels in-front of the DIY absorbers do the trick?
Regards
|
|
|
Post by Ethan Winer on Nov 8, 2016 17:45:36 GMT
Yes, good quality real acoustic foam (not cheap junk) works fine in front of a panel that's not fully absorbent.
--Ethan
|
|