Studio Acoustics: The organic natural way...

[Ethan Winer]

Originally Posted by Piedpiper

it sounds like you mightn't know enough to comment.

Not so, I was trying to be nice.

This page pretty well sums it up:

Passive Room Treatment

"Specs? We don't need no steenkin' specs!"

--Ethan

[Piedpiper]

Originally Posted by Ethan Winer

Not so, I was trying to be nice.

This page pretty well sums it up:

Passive Room Treatment

"Specs? We don't need no steenkin' specs!"

--Ethan

So is your point that his products are ineffective, overpriced or only not documented properly?

BTW, by "know enough" I meant about him and his products.

[Brainchild]

It's frustrating that there's no info about the performance - or even the intended application - of any of those products. I guess you're supposed to get in touch for a personalized consultation.

[Ethan Winer]

Originally Posted by Piedpiper

So is your point that his products are ineffective, overpriced or only not documented properly?

All three. It's intuitively obvious that small thin pillowcases are not going to have any useful effect at bass frequencies. And most of the other stuff I see on that site seem more like audiophoole tweaks than real products. Notice how none of the descriptions actually say what the products do. All you are told is where they should be placed.

--Ethan

[CaptPicard]

Originally Posted by Brainchild

It's frustrating that there's no info about the performance - or even the intended application - of any of those products. I guess you're supposed to get in touch for a personalized consultation.

Well, yeah, that was my temporary conclusion as well, leaving me with a bit of disappointment.
That's why my next step will be.... just ordering a bunch of various damping fibre panels, and start measuring using FuzzMeasure (as my first choice). I was thinking to create more density with the sheep wool using fine grid chicken (or rabbit) wire fencing, so if necessary it is possible to pack more material in a confined space.

It just looks like the only way, and I am feeling very positive about it. Could be great fun and DIY is really my way of dealing with this baby. First on tour with a band for a month in a few days time, then back home and start...
Newell arrive today, and I will use the waiting hours in between to read what he has to say. See ya later, and thanks for all the advices folks!

[Piedpiper]

Originally Posted by Ethan Winer

All three. It's intuitively obvious that small thin pillowcases are not going to have any useful effect at bass frequencies. And most of the other stuff I see on that site seem more like audiophoole tweaks than real products. Notice how none of the descriptions actually say what the products do. All you are told is where they should be placed.

--Ethan

It's also intuitively obvious that they are not intended for bass frequencies, as I said earlier, I can confirm that, having talked with Michael years ago. I'd like to keep the attitude separate from the facts.

[PaulP]

Originally Posted by Glenn Kuras

No you would not discard it because the absorption coefficient is based off the sabins. Sabins is really the number you want to see. The reason the AC may be higher is because the edge is not taken into the equation when calculating from Sabins. There are other factors, but the bottom line is Sabins is really what you want to know.

Speaking of edges... I just read an interesting section in the Master Handbook
of Acoustics where it says that absorbing panels spaced apart have quite
a bit more absorption than the same panels placed together, because the
edges cause diffraction (the edge effect). As much as twice as much
absoption at certain frequencies since there's about twice as many edges :

http://books.google.com/books?id=6tiJ1cwnwxoC&pg=PT149&dq=master+handbook+of+acoustics+absorbent+patches+diffuse#v=onepage&q=master handbook of acoustics absorbent patches diffuse&f=false

Paul P

[Ethan Winer]

Originally Posted by Piedpiper

It's also intuitively obvious that they are not intended for bass frequencies

Then by what logic would they be placed in corners and tri-corners?

--Ethan

[Ethan Winer]

Originally Posted by PaulP

absorbing panels spaced apart have quite
a bit more absorption than the same panels placed together, because the
edges cause diffraction (the edge effect).

There's more to the edge effect than diffraction. See Figure 2 in my article Alternative Test Methods for Acoustic Treatment Products. This figure shows that for a four-inch thick panel, exposing the edges adds 50 percent more surface area!

--Ethan

[Piedpiper]

Originally Posted by Ethan Winer

Then by what logic would they be placed in corners and tri-corners?

--Ethan

The logic, as I've heard it, is that sound pressure builds up at boundaries, and exponentially at boundary junctures and fires back out into the room/listening position. The Roomtune pillows are filled with fiberglass insulation and are faced with aluminum foil, facing out. Although they may be ineffective at low frequencies, they seem to help with midrange on up, cleaning up the chaotic reverberations while keeping the room lively. Ideally, larger 1' x 4' x 4" floor standing panels are placed in the corners in addition to tri-corner pillows and rectangular pillows at the mid point of wall ceiling junctures. Does this fit in with your understanding?

[Ethan Winer]

Originally Posted by Piedpiper

Does this fit in with your understanding?

Barely.

Acoustic treatment must be large enough to cover a significant portion of a room's surfaces. Even highly effective and thick absorbing material must be large to have a meaningful effect.

--Ethan

[Piedpiper]

Green's priority is to control only the corners where the most chaotic reverberations collect and then fire back out from. This way the room remains quite lively but more coherent. It's a very different approach than wholesale dampening.

[Glenn Kuras]

Originally Posted by Piedpiper

Green's priority is to control only the corners where the most chaotic reverberations collect and then fire back out from. THis way the room remains quite lively but more coherent. It's a very different approach to wholesale dampening.

I understand his logic, but it really does take surface area to be effective. Trust me I would love to be able to sell something smaller to save on shipping but the plan fact is size does matter.

[Piedpiper]

Originally Posted by Glenn Kuras

I understand his logic, but it really does take surface area to be effective. Trust me I would love to be able to sell something smaller to save on shipping but the plan fact is size does matter.

Thanks. So would his method make sense to you if the products were similar but bigger? Are you implying that they may be effective but only at relatively high frequencies? Would it make sense that may be Green is focused primarily on soundstaging, which I'm imagining would be primarily effected by higher frequencies, and even possibly enhanced in a HiFi sort of way by a highly reflective room minus the most chaotic of reflections (from the corners).

[Weasel9992]

The issue as I see it is this: even if they were effective in that way, you're solving a problem that's not even on the top five. Small rooms are dominated by low frequency standing waves, so that has to be dealt with first and foremost. The first place you're usually looking to work on for that problem is the corners, so you're really just wasting space by employing a treatment that addresses high frequency issues there. You need to be using that space for bass trapping, not high frequency control. As a matter of fact, in the average small-ish space, most of the space you have available for treatment usually needs to be at least broad band, if not bass trapping.

In other words, the kind of corner treatments you're talking about are kind of a waste of space. I mean, they might work just like you're suggesting (maybe), but even if they did you'd be solving a tiny problem at the expense of what's almost certainly the biggest problem in the room.

Frank

[Ethan Winer]

Originally Posted by Piedpiper

So would his method make sense to you if the products were similar but bigger?

They'd have to be much bigger and also much thicker. Those little corner things work mainly on placebo effect.

Would it make sense that may be Green is focused primarily on soundstaging

In that case the proper solution is large panels at the side-wall and ceiling reflection points.

No product performance data is given, which is equally relevant. For a product that small, the only data that matters is sabins of absorption. An absorption coefficient is useless for too-small devices like those.

--Ethan

[Piedpiper]

Thanks. What purpose do you suppose the foil serves?

[Ethan Winer]

No idea. On a proper bass absorber it could serve as a membrane to increase LF absorption. But on something that small and thin, who knows. Again, the key for me is that no data at all is offered.

--Ethan

[Piedpiper]

Originally Posted by Ethan Winer

No idea. On a proper bass absorber it could serve as a membrane to increase LF absorption. But on something that small and thin, who knows. Again, the key for me is that no data at all is offered.

--Ethan

thanks.