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do bass traps and ceiling clouds need rigid back? Bass Traps
Old 31st March 2010
  #31
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Bubbagump's Avatar
 

Quote:
Originally Posted by DanDan View Post
I am afraid I must disagree with several posters above. I believe FRK on the back of Cloud panels is very beneficial. I have two reasons for this.
To clarify what I was meaning, I was referring to like 3/4" MDF so as to box in a trap or the like, not FRK or other thin membranes.
Old 31st March 2010
  #32
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Quote:
Originally Posted by morebass View Post
Glen

I don't need to take a second look.

You might think those figures are impressive .... I certainly don't.

Unlike some (you), I am not trying to promote products, or myself. I understand that you want to defend your product, and thats fine, but don't try to convince me that they will handle bass standing waves because they won't.
And for what its worth, they are ugly.

And now I'm bored.
If your so bored then WHY are you here???
Glenn, I would not worry about it, the prices are VERY good.
And I would go by what the BBC noted, and not worry about anything else..
Old 31st March 2010
  #33
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Glenn Kuras's Avatar
Quote:
Originally Posted by nosebleedaudio View Post
If your so bored then WHY are you here???
Glenn, I would not worry about it, the prices are VERY good.
And I would go by what the BBC noted, and not worry about anything else..
Trust me I am not at all. I can hold my head up pretty darn high with numbers like that and my point was not to "promote" our product but show what broad band can do. If 23.97 sabins at 80hz is not enough to prove that then nothing will. Also I can hold my head up high that my company dedicates a ton of time to educating people about acoustics and not just people buying our product. I wish the guy the best of luck.
Old 31st March 2010
  #34
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Quote:
Originally Posted by Glenn Kuras View Post
Also I can hold my head up high that my company dedicates a ton of time to educating people about acoustics and not just people buying our product.
Amen.

You guys need not answer to anyone.
Old 31st March 2010
  #35
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Quote:
Originally Posted by Glenn Kuras View Post
Trust me I am not at all. I can hold my head up pretty darn high with numbers like that and my point was not to "promote" our product but show what broad band can do. If 23.97 sabins at 80hz is not enough to prove that then nothing will. Also I can hold my head up high that my company dedicates a ton of time to educating people about acoustics and not just people buying our product. I wish the guy the best of luck.

Here's a pic of a custom wall panel and bass trap I designed/built, looks pretty nice..
Attached Thumbnails
do bass traps and ceiling clouds need rigid back?-new-ods-side-wall.jpg  
Old 31st March 2010
  #36
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Quote:
Originally Posted by Glenn Kuras View Post
Also I can hold my head up high that my company dedicates a ton of time to educating people about acoustics and not just people buying our product. I wish the guy the best of luck.
+1 thumbsup

Recognizing the best,
Andre
Old 31st March 2010
  #37
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Quote:
Originally Posted by [email protected] View Post
I like it.

I don't know that at that thickness, a rigid back would redirect much. Personally, I'd want it breathable so the gapping will better effect your vertical mode.

[EDIT] you may just want to leave a bit of an overall air gap and hang them without overlap. I'm just thinking you're setting yourself up for a lot of hanging logistical headaches, and if you don't get the angle the same on all of the traps, it may end up looking hap-hazard.
Well,I was thinking at this point about unfaced, and slanted... but we'll see. I got such a phenomenal deal on the stuff I just picked up 60 sheets... it's filling up my entire driveway. I did the math on superchunking every available corner, 4 inches on every surface, etc... we'll see if I've lost my mind or not...

Before I decide for sure about ceiling, I'm gonna move all furniture in, and see if I can live with this space if panels are off the wall AT ALL, or if it's bordering on too cramped even wall mounted... then I can see about ceiling... unloading now...
Old 1st April 2010
  #38
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Quote:
Originally Posted by DanDan View Post
Hi Glenn, I don't have Lab tests of course. But unfortunately I have a before and after in the same room. Not done rigorously, but a very clear result.
Worse LF anomalies. On top of that a little theorising....
Surely HF will be absorbed by 3 inches of 705 or whatever. LF, say from 500 Hz down will pass right through the 3 inches. It will vibrate the damped FRK, similarly as it does when the FRK is in front. There will be some absorption. The remaining (most of the) LF will continue to the boundary, bounce back and get hit again by the damped FRK. All good, and no down side that I can see. I can't theorise a way around this. Ideas welcome here! Plus of course, to me pain, I found this to be measureably true. I had to replace the modified traps.


DD
Do you have the before and after graphs of it?? I have the guys coming over from the UK plant all next week but maybe I can test it also in a couple weeks. I would not be able to put them on the ceiling but against the wall.
Old 1st April 2010
  #39
Gear Guru
Test

I will take a look around to see if I saved it. I am a serial deletor. (DD)
On the floor may be a practical way to test. Four little blocks to support.
DD
Old 1st April 2010
  #40
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Glenn Kuras's Avatar
Quote:
Originally Posted by DanDan View Post
I will take a look around to see if I saved it. I am a serial deletor. (DD)
On the floor may be a practical way to test. Four little blocks to support.
DD
I have a desk and don't want to move it. heh I would think the side reflections should act the same.
Old 1st April 2010
  #41
Gear Guru
Lost

Hi G, of course all the reflections should have similar effect. Unfortunately I don't seem to have the results of those tests I did. Didn't realise how significant it was at the time. So all we have is my assurance that I was convinced enough to reverse my decision. i.e. I replaced the FRK backing on either six or eight traps.
DD
Old 1st April 2010
  #42
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Glenn Kuras's Avatar
Thats cool, I will keep you posted if and when I try it.
Old 2nd April 2010
  #43
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Quote:
Originally Posted by morebass View Post
I think the mutual appreciation society on here is very sweet .......

This is an award winning studio I designed 14 years ago.
Yes it is a dome, and it's tuned down to 20hz.
Mr. Kuras I'm afraid you are not in my league.
^^ What is this cat's problem? We're usually a friendly bunch around here, but Mr. Bipolar here seems to be unnecessarily confrontational. What gives, Morebass? Perhaps a lesson or two in effective argument is in order.. or maybe more meds.
Old 2nd April 2010
  #44
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Actually, I was enjoying the "let's ignore this a-hole" approach that this thread has adopted. But since you brought it up...
Old 2nd April 2010
  #45
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Quote:
Originally Posted by [email protected] View Post
Actually, I was enjoying the "let's ignore this a-hole" approach that this thread has adopted. But since you brought it up...
What a-hole?
Old 2nd April 2010
  #46
Gear Nut
 

Quote:
Originally Posted by [email protected] View Post
Actually, I was enjoying the "let's ignore this a-hole" approach that this thread has adopted. But since you brought it up...
Ignoring the guy is no fun whatsoever. I was hoping to arm wrestle him the parking lot for a 6 pack of PBR.
Old 2nd April 2010
  #47
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johndykstra's Avatar
 

If it's a dome, I wonder where he's putting his corner bass traps?heh
Old 2nd April 2010
  #48
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Glenn Kuras's Avatar
Quote:
Originally Posted by gremmy View Post
Ignoring the guy is no fun whatsoever. I was hoping to arm wrestle him the parking lot for a 6 pack of PBR.
Actually I have some of my UK guys flying in from the GIK UK plant today and plan on stocking my frig with PBR. I have told them that is all they can drink!! heh

Honestly when someone starts acting like that on GS I find it better just to ignore them. Why start the insults back and forth? In the end it makes the place look and smell bad and this part of GS has always been a "no ass zone" for the most part. If someone has the need to come at me, what can I do? It really is not worth it, nor do I have the time. As I said I wish him the best of luck.
Old 2nd April 2010
  #49
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He's right though Glen, you guys aren't in the same league. Just not the way he meant it.
Old 2nd April 2010
  #50
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Quote:
Originally Posted by morebass View Post
Glen

I don't need to take a second look.

You might think those figures are impressive .... I certainly don't.
You can explain why? 23.97 sabins at 80hz sounds impressive to me, but please educate me.

It's no doubt though that a panel resonator like Modex Plate has very impressive coeffiecient in the lowest frequencies. And the same goes for a Helmholtz resonators, but in a narrower range.
RPG Diffusor Systems
I'd love some of those Modex Plates, but darn they're expensive!
Old 2nd April 2010
  #51
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Glenn Kuras's Avatar
Quote:
Originally Posted by bwo View Post
You can explain why? 23.97 sabins at 80hz sounds impressive to me, but please educate me.

It's no doubt though that a panel resonator like Modex Plate has very impressive coeffiecient in the lowest frequencies. And the same goes for a Helmholtz resonators, but in a narrower range.
RPG Diffusor Systems
I'd love some of those Modex Plates, but darn they're expensive!
Just to explain it to people that might not understand that number.

If you convert that to a absorption coefficient it would come out close to a 3.00. A 1.00 is considered a 100% absorption of the give frequency. the reason it does test so high is the thickness (the sides) and sound coming from the back (also the front is a semi membrane). When a person is designing a room they know how many sabins it takes to get a certain frequency in check. Needless to say for a 4x8 panel 23.97 is one of the best around. Further to that we designed it so it starts to fall off around 500hz or so to not deaden up the room to much on the high end.
Once again I am not trying to promote our product, but to show what ridged fiberglass and mineral wool can do if done right. And I am not against tuned traps (hell we build them like I pointed out), but those are more for specific problem frequencies
Old 4th April 2010
  #52
Gear Nut
 

Glenn: your advice, and the advice of others who have companies that sell acoustic products like Ethan, have been consistently some of the best, most honest, and least "promotional" I've come across.

In fact, I actually legitimately felt guilty when I DIY my control room traps using your and Ethan's (and scores of others on here) knowledge, knowing that this knowledge you have is your livelihood.

And those monster bass traps numbers are fantastic, and I actually find them to be a great price/performance ration and I do plan on picking some up when I have the quid.
Old 4th April 2010
  #53
Gear Guru
FRKn Test

I found my test. It shows the difference between FRK on the wall side of traps versus without. Can't double post, so it's here BASS traps with FRK (or something like it)

DD
Old 5th April 2010
  #54
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RKrizman's Avatar
 

Quote:
Originally Posted by DanDan View Post
I am afraid I must disagree with several posters above. I believe FRK on the back of Cloud panels is very beneficial. I have two reasons for this.
1 FRK on the front of panels is known to enhance LF absorption.
Since the back of the panel is only a couple of inches away, why would the FRK not enhance LF absorption there also? A couple of inches is a tiny tiny fraction of the wavelengths here.
I was under the impression that the way FRK increased low end absorption was because it reflected more high end, so less high end absorption means more low end absorption by comparison. If the FRK is on the back of the panel this would not be the case.

Actually, this is something I've wondered about. Is the FRK really absorbing more bass or just changing the ratio of absorption by reflecting highs?

-R
Old 5th April 2010
  #55
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Glenn Kuras's Avatar
Quote:
Originally Posted by DanDan View Post
I found my test. It shows the difference between FRK on the wall side of traps versus without. Can't double post, so it's here BASS traps with FRK (or something like it)

DD
Thanks Dan,
Been going a little nuts around here, but will check it out when I can.
Old 5th April 2010
  #56
Gear Guru
Tests etc.

R- The FRK actually increases the LF absorption. Ethans tests show that clearly. No-one really knows how this membrane/panel system works, but it does. We could guess that it is some sort of damped resonance. However there are many unexplained things about it. e.g. The LF effect is significantly enhanced if the FRK is on the outside, facing the listener. Why, I wonder?
Cheers Glenn, the test is not that impressive. In reality I would be inclined to use FRK when it comes attached. Insulation is often available ONLY in that from around here. If using Roksil or whatnot I am not sure I would go to all the trouble of attaching a membrane for the seemingly small improvement.
DD
Old 6th April 2010
  #57
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I thought I remember reading somewhere, that the membrane heightens the sensitivity to low frequencies because it forces the face of the absorbent to perform as a system

kinda like Dan said.
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