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Auralex Roominator Kits??? Any good??

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Re: Auralex Roominator Kits??? Any good??

Postby Digipenguin » Wed Nov 24, 2004 7:34 pm

Moderators, can we just lock this thread or better yet, delete it. It's nosediving............and it never reaches the ground.

Hey guys, can you take this back to RO or Studiotips?
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Re: Auralex Roominator Kits??? Any good??

Postby Digipenguin » Wed Nov 24, 2004 7:35 pm

Please?
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Re: Auralex Roominator Kits??? Any good??

Postby Scott R. Foster » Wed Nov 24, 2004 9:14 pm

I refuse to descend into the weird world of personal problems some would prefer... but for the record, it is true, I am technically incorrect to refer to a MiniTrap as a panel absorber - it is in fact a membrane [or diaphragm] absorber with a mineral fiber damping core.

The MT is made from a 2" 705 FRK [6 pcf] mineral fiber type panel with a reinforced paper foil [aluminum] facing and an additional back panel of 1" of 703 type material (total 3" of mineral fiber with the paper foil diaphragm on the front side).

The rigid fiberglass core is covered with a heavy synthetic cloth which is slightly glued on the fiberglass backside (703) and onto the foil at the front side (front = 705 FRK paper foil).

There is nothing magic, or even particularly interesting about the device... the concept of covering mineral fiber with a membrane to make a dampened absorber is an old and well understood idea. A similar effect arises from installing paper backed house insulation between studs [though with a higher peak due to the varying weight of the paper membrane and the nature of the damping from the different weight of the material to which it is attached]. One could emulate the effect more closely by simply covering a pair of panels of fiberglass or rockwool with some type of membrane [foil, paper, cloth, plastic], or choosing a foil backed panel in the first place. Different weights of membrane, and damping material will yield different peaks. You might consider a lower density panel and/or a heavier membrane if you seek better overall low frequency absorption or a lower peak [respectively].

The FRK foil and the heavy cloth serve the purpose of the "membrane" in the MT and cause a peak in the absorption characteristic to the device. This is diverse from a true panel trap in that limp membranes do not exhibit the bending waves [and absorptive resonances] that a stiff panel will. But that's all a tempest in a teapot to the lay user... both are simply forms of devices that present resonant boundaries to the sound source and have the "Q" of the resonating element broadened slightly through the use of a damping element [mineral fiber in this case].

The MT is surrounded by a metal frame with decorative perforations. It is a stable and smart looking unit, but damned heavy due to the metal frame. It is also very expensive given that one could build an acoustically similar device for a fraction of the cost [buy some 705 FRK and add a heavy cloth cover and a 703 backing and Bob's your uncle]. FWIW I think this type of device should be avoided... but if that’s what you want, you CAN build one.

The big difference between a "roll your own" damped membrane device and a factory built MT is the frame... if you need/want a heavy metal frame and are willing to pay for it... fine by me. If OTOH you don't need a heavy frame, but want to get similar results for less money, you could build a lightweight wood frame for a similar core of stuffings and then cover with fabric of your choice.

The ML OTOH is a faceted wedge made of a high end acoustic grade foam... also smart looking. The material is not only acoustic grade, it also has fire resistant properties lesser foams will not exhibit. ML's are also expensive, but they are light and absurdly easy to install [toss em in the corner]. Comparing these to crappy foam wedges made of inappropriate materials is silly.

If you have a source for acoustic grade foam, I reckon you could also build ML equivalent units for yourself with a foam cutting tool and achieve some cost savings, but I have no information on cost and know of no one who has tried that method. Also, the facets are acoustically relevant... so you might want to look into how to get that style of faceting [a simple flat face will not work as well at giving a flat absorption curve across the band].

FWIW I have no axe to grind with any manufacturer, though I detest deceit, particularly when science is involved... it just aint cricket in my book. ML's and MT's are what they are, and if they float your boat then God bless your little heart, but spreading dis-information to folks looking to understand the physics and materials science behind such devices is just wrong.

Like most things "acoustic" both of these devices are fairly pricey IMO, neither of em are magic, and they won't do anything that devices you can build for yourself won't do just about as well [or better]. Moreover, unlike the ML's, the MT's aint broadband... and claims to the contrary are false.

IMO, when it come to absorbers, building your own is the "best" answer if you can muster up some basic craft skills [or know someone who can]. For those who cannot get it together enough to build acoustic fixtures, or wish to avoid the chore... pay the man and get on with life. But don't expect me to go along with your dream that you have acquired something magic with your money... you didn't.

Sometimes when folks spend large sums [of their own, or their client's money] they have a need to pretend that they got something unavailable to others willing to work their toward the same goal by different means... sometimes this is true... a Yugo aint a Rolls... but sometimes, all they did was avoid the chore of doing it the hard way [earning their fee?].

Good Luck!

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Re: Auralex Roominator Kits??? Any good??

Postby Paul Woodlock » Wed Nov 24, 2004 9:32 pm

Digipenguin wrote:Moderators, can we just lock this thread or better yet, delete it. It's nosediving............and it never reaches the ground.

Hey guys, can you take this back to RO or Studiotips?


Why?

Presumably you're not a devotee of censorship, so it's only fair that people have a chance to put the record straight regarding the perfomance and properties of both proper Foam Absorbers, DIY broadband Traps, and narrowband Membrane Absorbers such as Mini-Traps.

Do you not think it is fair that readers should be able to make an INFORMED choice on acoustic treatment products without being misinformed?

So why do you want the thread deleted? Do you have a hidden agenda?

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Re: Auralex Roominator Kits??? Any good??

Postby cc. » Wed Nov 24, 2004 9:34 pm

Paul Woodlock wrote:
cc. wrote:
My experience with the mini traps is that the lack of absorbtion at the higher frequencies is a feature. It is true that after putting in the mini traps there were still problems higher up which had to be fixed by installing foam. But I needed the foam anyway: to cut down reflections either side and above the mix position and to deaden my vocal recording area. After doing this the room's pretty balanced.

Greetings CC :)

You say it's a feature in your experience, but you don't really say why.

Sorry, I didn't explain that very well. It's a feature for me because I have enough HF absorbtion in my room with the foam I am using for the reflections around the monitoring position and to deaden the vocal area. If my bass traps were also absorbing HF I'd have about two or three times more HF absorbtion than I have now, and that would be too much for me.
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Re: Auralex Roominator Kits??? Any good??

Postby Paul Woodlock » Wed Nov 24, 2004 9:43 pm

cc. wrote:
Paul Woodlock wrote:
cc. wrote:
My experience with the mini traps is that the lack of absorbtion at the higher frequencies is a feature. It is true that after putting in the mini traps there were still problems higher up which had to be fixed by installing foam. But I needed the foam anyway: to cut down reflections either side and above the mix position and to deaden my vocal recording area. After doing this the room's pretty balanced.

Greetings CC :)

You say it's a feature in your experience, but you don't really say why.

Sorry, I didn't explain that very well. It's a feature for me because I have enough HF absorbtion in my room with the foam I am using for the reflections around the monitoring position and to deaden the vocal area. If my bass traps were also absorbing HF I'd have about two or three times more HF absorbtion than I have now, and that would be too much for me.

Greetings CC :)

Yes, but HF is NOT the area in question. The area in question for trapping are the Room Modes. Which extend from the bass to the lower mids.

HF control is not the focus of the discussions in this thread. We're talking about control of Room Modes and the best ways to do this. In a fair manner I might add.

This is why turning a caveat of a narrowband trap like a Mini-Trap into a 'feature' is SILLY in this context.

I hope that explains things.


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Re: Auralex Roominator Kits??? Any good??

Postby Ethan Winer » Wed Nov 24, 2004 11:23 pm

Scott,

> FWIW I have no axe to grind with any manufacturer <

Thanks for your reasonable and calm response. Now, with the following graphs we can all put to rest the notion that MiniTraps are tuned or narrow band. I'm hoping that with this data you and Paul will finally "get it" when you see these measurements that clearly show broadband improvement after adding RealTraps to a room.

The two "waterfall" graphs below show the modal ringing in the RealTraps lab - a 16 by 11-1/2 by 8 foot room - empty (top) and with traps (bottom):


Image

Image


The next two graphs show the RT60 of the room empty, then trapped. The frequency extends to 1.6 KHz which I'm sure we all agree is well past the bass range. As you can see, the reduction in RT60 is quite consistent all the way up to the 1600 Hz cutoff:


Image

Image


I know it looks to you guys like a MiniTrap is tuned, but it really isn't. Here's the data from our site to refresh everyone's memory:


Image


We all agree that the peak around 100 Hz is mainly related to corner mounting. Then, somewhat above there, the absorption falls and levels off to the 10 KHz data limit. Just as important here is the difference between the frequency of maximum absorption versus the range of effective absorption. 8 Sabins is a lot of absorption, and both MiniTraps and MondoTraps exceed that to well past 1 KHz. Again, remember that 8 Sabins of absorption from a panel having 8 square feet of front surface is 100 percent absorption. So to criticize a MiniTrap as ineffective above the mid-bass range is simply incorrect.

--Ethan
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Re: Auralex Roominator Kits??? Any good??

Postby Paul Woodlock » Wed Nov 24, 2004 11:58 pm

just to be clear...

The FOAM in Ethan's graph above is the ineffective Foam-By-Mail Foam, and is NOT valid as a comparison between Mini-Traps and typical ACOUSTIC Foam.

Ethan you spent a lot of time trying ( without success ) to discredit the results from an accredited lab earlier in this thread. And now you show data from home tests done with ETF and expect them to have more credibility.

All your graphs do is show Mini-Traps have some effect and are better than fake acoustic foam.

No one's arguing that Mini-Traps don't have an effect. No one is saying MiniTraps are crap either.

Ethan is you're going to play fair then you MUST show comparable data between real acoustic Foam like the Auralex MegaLENRDS and the Mini-Traps, with the same frontal area that results from mounting in a corner.

You see that is exactly what the StudioTips Lab Data shows. And the results show that BOTH the MegaLenrds and DIY rockwool corner traps perform much better for the task in hand than Mini-Traps.

In fact even a slab of Rockwool across the corner that takes up the same space as a Mini-Trap performs better.

TEST DATA: http://forum.studiotips.com/viewtopic.php?t=536

And to anyone who thinks this thread should be closed.....

These discussions are important ( as well as interesting ), and go a long way to showing the layman the variosu choices on offer.

As long as it IS kept civil. But that means Ethan must stop trying to discredit the StuioTips Lab Data when he knows the tests were done to an accuracy at least the same as his own lab tests.

All I ( and the others at Studiotips ) want to do is cut the marketing hype, and give people a fair choice of the products on offer.

The campaign by Ethan to discredit Foam by using a fake product is simply unfair and unprofessional. As long as he continues to do this, he must be accountable for his actions.

And I must REPEAT that contrary to the over the top claims by Ethan, NO ONE is trying to ruin Ethan's business. NO ONE has a personal agenda towards Ethan regarding performance of his products and performance of Foam or any other absoprtion device.

Ethan says we don't target Foam-By-mail. Well that's becuase they don't spend half their lives trawling arund the forums spreading false BS about theit fake products. If they did, we'd be on them like a ton of bricks ;)

All we want is a marketing BS free and fair playing field. If proper test data shows one company's products to not be as good as others ( as is the case ), then it's upto the manufacturer of those products to either improve them or drop the price accordingly.

My only agenda is to protect the customer. And that's because I am one. :)


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Re: Auralex Roominator Kits??? Any good??

Postby Avare » Thu Nov 25, 2004 6:20 am

Great magazine and great forums! I feel sad that I have to have my debut post here be a defense against uncalled for statements about me. Fortunately, several people here know me from other forums, and thus the veracity of my statements. Others can easily search on the relevant forums to confirm my statements. My posting name is always "avare." I do not use any aliases.

Ethan Winer wrote:
These guys - Eric Desart, Paul Woodlock, Scott Foster, Dan Nelson, and Andre Vare - have been making trouble unprovoked for more than a year now. This is just one more in a long line of audio forums where they show up with the sole motive to insult me and my company's products. Identical threads have occurred at Harmony-Central, Recording.org, the AV Science forum, GearSlutz, and probably one or two more I'm forgetting.

I have never written disparaging comments about Ethan's company, its products, or Ethan.

I have never even posted on Harmony-Central! The forum where I post most often is John Sayers' Recording Studio Design.


Ethan:

Please correct your references to me.


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Re: Auralex Roominator Kits??? Any good??

Postby Digipenguin » Thu Nov 25, 2004 7:42 am

Paul Woodlock wrote:
So why do you want the thread deleted? Do you have a hidden agenda?

Paul

You know what, Paul?

I had nothing but the utmost respect for you.
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Re: Auralex Roominator Kits??? Any good??

Postby Scott R. Foster » Thu Nov 25, 2004 7:56 am

Your Jedi mind tricks won't work on me Ethan. You can put all the lipstick you like on that pig... she still aint getting invited to the prom.

As you well know, reliable LF absorption data cannot be obtained in a garage using ETF, and any claims made about low frequency absorption devices based on such data are bogus.

OTOH... we have published data on the MT's absorption curve which was obtained from Riverbank Acoustic Labs. This institution has impeccable credentials, and reverb chambers capable of providing reliable data below 100 Hz. The RAL data on MT's looks like this:

http://forum.studiotips.com/viewtopic.php?t=536

As you can see MT's are narrow band. The Sabin count for MT's drop like a rock both above AND below 100 Hz. Much more so than for SCA's [a comparable device - but without the membrane of the paper foil - the membrane is what accounts for the sharp peak exhibited by the MT, and the absence of this sharp peak in the SCA].

Also, there is a big dip between 125 and 400 Hz in the MT's absorption curve... then the Sabin count rises back up at 630 Hz.. only to dip again... now why would anyone want that in a device? What room is the MT designed for? What is the purpose of this "feature" of an absorption curve that peaks and dips and peaks and dips?

For general applications I would greatly prefer the curve on an SCA to that of the MT.

Note how the SCA does not have a large dip from 125 Hz to 400 Hz like the MT... instead it has much flatter line all the way to 5k Hz.

Given you can build an SCA for about $20 I just can't see any reason not to use em versus the MT. The SCA curve has not only got a better Sabins across the band [save the 100 Hz peak], its much flatter!

OTOH, adding material behind the SCA will help make the curve more like the SuperChunk [got insulation scraps?].

http://forum.studiotips.com/viewtopic.php?t=534

My $0.02

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