Small Room Acoustics and Diffusers

[artto]

I'm going to open a can of worms here but feel free to voice your opinion even if I vehemently disagree with it. Of course, if I do disagree, I'll likely challange you to prove your point of view [8-|]

In doing some searches regarding Room EQ Wizard to do some diagnostics on my room and in particular the new subwoofers I recently acquired, I came across a YouTube video by Ethan Winer called "All About Diffusion". As some of you may know there seems to be a "new" school of thought regarding what is or is not "really" a "diffuser".

First off, I'll get to the point regarding Ethan's video. At the end of the video Ethan performs a little demonstration playing and recording a guitar about 6" from various types of "diffusers". There are some who now claim that polycylinders are not really "diffusers". I for one disagree with that perspective, at least to some extent, especially depending on how the polycylinder is implemented.

The "polycylinders" used in Ethan's demonstration are very symetrical. They are positioned in one direction (vertically), all the same size, height, radius and depth. I guess in this configuration the term "poly", meaning "many" is refering to the array of several identical cylinders. However, I aver there is another interpretation of the term "polycylindrical". To me, this can also refer to a multiple array of dissimilar size, depth, radius and orientation of cylindrical surfaces. And to me, there is also a third implementation of "poly"cylindrical where each cylindrical surface itself has a non-uniform radius, or poly-radius to its surface, much like a "ship curve" or the transitional multiple radius used on on railroads or highways. In these configurations there is no "inside" / "outside" areas between adjacent diffusers to focus the sound instead of diffusing it.

What I found particularly interesting about Ethan Winer's video is that I actually preferred the sound of the guitar with the polycylinder at the "inside" of the polycylindrical diffusers (inside referring to the outermost "bulge" in the polycylinder ~ "outside" referring to the outside edge where two polycylinders meet ~ the area that causes a focusing of the sound resulting in coloration) as opposed to the QRD diffuser. It reminded me of the time I was listening to the opening gala performance of the Walt Disney Concert hall on WFMT. I really liked what I heard, even on the radio. So I looked up the hall and to my surprise what did I find? Curved surfaces. Lots of poly-curved surfaces. An atmosphere much like my listening room.

I would also like to take this opportunity to explain that the polycylinders in my room are not constructed like the ones Ethan Winer choose to build and demonstrate. Nor are they implemented the way his are. The diffusers in my room are multiple radius surfaces. They are not parallel to each other even though they may appear to be due to lighting issues, and there are no side by side "outside" edges to focus and color the sound. They are generally much large in size as well and of much greater depth.

If you're going to make "poly"cylindrical diffusers, the ones Ethan showed are exactly not the way to build them. He also chose a rather difficult construction method, one which reminds me of my late father-in-law who was a sewer contractor before turning to home building. I was working for him one summer while in college and came up with the same bright idea on a large piece of concrete storm sewer pipe we had to cut to fit to size on site that Ethan did with the Sonotube. Ed cursed the hell out of me (architect in training) and I never heard the end of it [:S]

[thebes]

I'll be watching this debate with interest as it develops.

Here's the link to the video Arto's talking about:

[Quiet_Hollow]

Hi there Artto..

Do you know of anyone else that has employed diffusers of the Klipsch-type to the extent you have?

Your place was the first I've ever seen and heard them used (like I get around much these days anymore[])...and from what I experienced when I visited, they work exceptionally well. [Y]

Now...that gentleman I spoke to you about, located up this way with the Magnepans, employs a few strategically-placed polycylinder types around his room in addition to other treatment, and it sounds just as nice too. [Y] His are a little more advanced than a sonotube though, the room is a bit larger, and he's got slightly different acoustic requirements with his speakers being dipolar.

To tell you the truth, it's simply pleasing to be in a treated room, regardless of system. That sonic environment will be #1 on my list at the next residence.

My tastes are a little biased however. I'd prefer an acoustic "black-hole" from 500 Hz on up if I could get it, but I understand not everyone's ears are comfortable with that. I spent too much time in ear plugs and muffs during the line of work....just got used used to the sound of my own breathing after a while.

I attached a photo I came across of the movie theater in the evacuated town of Pripyat, Ukraine. It shows the cieling covered in diffusers sporting a geometry I'm growing quite fond of.

[garyrc]

Well, the worst sounding were the bare wall and the absorber .... I'll have to play it again through headphones, then through K-horns.

I guess I wonder about the validity of tests with the instruments and mics so close to the diffusers or absorbers.

The best sounding "small" room (24 x 16, with a 9.5 foot ceiling) I've ever heard had a huge brick fireplace covering 75% of one wall, with the bricks / rocks in many different planes, partly tilted blinds on the windows, lots of other irregularities including beams, with a Persian rug, and a hardwood floor exposed around the edges of the rug. The walls were plaster, with lots of built-in nooks. I've been trying to simulate that room ever since. We are now experimenting with diffusers, bookshelves, art objects, and a small number of strategically placed absorbers. The worst rooms I've heard are either overdamped Audio or Home Theater showrooms with lots of absorbers, even a few overdamped commercial theaters (prob to keep the dialog articulate -- but dialog was fine in nearly all of the live and interesting sounding older movie houses), or the occasional multi-purpose travesty (often a gym with a stage).

Do you know of anyone else that has employed diffusers of the Klipsch-type to the extent you have?

Klipsch gave the credit to Dr. Bonner.

[mustang guy]

There is some good information in this thread:

http://forums.klipsch.com/forums/t/66726.aspx

I am currently reading the PDF's Bill attached. When I first heard the term polycylinder, I was thinking it was a sonotube type cylinder made from polypropolene. []

[Don Richard]

You have to keep in mind that Winer has a product that he sells and is trying to show it in the best light.

[garyrc]

I
would think using several different radii and orientations would be
helpful, but the studios pictured in the other thread seem to use blocks of identical polys cheek-by-jowl????



Also, although Winer only uses horizontal diffusion to avoid "wasting"
diffuse reflections, wouldn't a ceiling receiving diffuse reflections
from wall diffusers that are both horizontal and vertical spray the reflections out at all kinds of crazy angles (depending on incidence), making the room sound even more spacious? Granted, reflections hitting a carpeted floor would be wasted, but not those hitting a person's ears from any angle?

[artto]

Hi there Artto..

Do you know of anyone else that has employed diffusers of the Klipsch-type to the extent you have?

I attached a photo I came across of the movie theater in the evacuated town of Pripyat, Ukraine. It shows the cieling covered in diffusers sporting a geometry I'm growing quite fond of.

No, I don't know of anyone else who has. I think Gil or someone posted something about 7 years ago on the thread mentioned above that someone in Australia was experimenting with. It has more polys than we usuallly see. It all looked very temporary at the time. And it also looks like that fellow also used a bunch of egg cartons. PLEASE folks, whatever you do, don't use egg cartons for acoustics! Especially the cardboard type. They are terrible acoustical devices.

Tom, if you like that geometric look you should visit the Foellinger Great Hall at U of I in Urbana. In all honesty, that room was the inspiration for my room. However I soon realized that the geometric diffusers wouldn't be very effective in my room's size so I decided to try and create a similar atmosphere using poly's and other treatments.

[artto]

I
would think using several different radii and orientations would be
helpful, but the studios pictured in the other thread seem to use blocks of identical polys cheek-by-jowl????



Also, although Winer only uses horizontal diffusion to avoid "wasting"
diffuse reflections, wouldn't a ceiling receiving diffuse reflections
from wall diffusers that are both horizontal and vertical spray the reflections out at all kinds of crazy angles (depending on incidence), making the room sound even more spacious? Granted, reflections hitting a carpeted floor would be wasted, but not those hitting a person's ears from any angle?

Yes, I believe the "cheek-by-jowl" as you put it was the way polycylinders were originally deployed back in the early 40's. It wasn't until some short time later that the idea having different orientations and multiple polys with different radius came along. Quite honestly, I kind of discovered the advantage of multiple (varying) radius polys by accident after hanging some large 4'x8' sheets from the ceiling. Over time the "bow" began to sag towards the floor creating more of a "breast" shape in section profile. As I began to think about this I decided it was a good thing and decided not to try make it more uniform by providing some kind of support for a contiuous radius.The polys on the upper part of the side walls in my room are positioned more like "fish gills", at angles overlapping each other. This location will also be the first area I install Roxul "Safe n' Sound" rigid insulation behind the polycylinders to create a full length wall bass trap.

And think about the horizontal orientation of diffuser curve. At the floor (in my room) there isn't much if any focus effect causing coloration because of the heavy carpeting and padding. At the ceiling it doesn't really matter much ~ this is where there is the least amount of diffuser curvature and since it is not parallel to another diffuser on the ceiling the diffuser is essentially scattering the sound waves across the ceiling at different time intervals anyway, and there's no "nook" for the sound to get focused in causing coloration as in Winer's demonstration. And also keep in mind that the diffusers in my room, although they may look as if they are parallel to the walls, are not. I had to "twist" them somewhat so the lighting shadow lines would appear symetrical. Due to the location of ceiling joists I didn't really have much choice as to the placement of recessed lighting cans. Back when I built this room track lighting was not as available and varied at reasonable cost as today.

[WMcD]

I kinda respect Winer because he giving some demonstrations and is a voice for room corrections.

He isprobably correct that absorption panels are effective. I'll add,they don't look weird.

The slap echo thing: I've heard it in some rooms,including my living room. OTOH, I tried it in my brother-in-law's dining room which has not too much furnature and all is hard surfaces (sheetrock and a ceramic tile floor. There was no flutter or boing.

Someplace I read an acoustic's expert say: If some consultant visits you, demonstrates a flutter echo, and says you need room treatment (based on the demo . . . run for the hills. Meaning, this doesn't prove too much. I think the issue is that when you do the "slap" test,your sender (the slap) and your ears are close together. Implied is that a more accurate test is to have someone clap at your speaker position, and you sit at your listening position.

I have not tried it. But with recording gear being part of most laptops, maybe we all should.

Also, somewhere I read an article showing that polycyliners become very less effective when they are arranged in a washboard fashion. The photos in the articles I've posted show just such washboards. OTOH, Artto's room is not like that at all. The same can be said of major classical concert halls. The ancients made grand, sweeping, curved balconies, not washboards. Maybe they knew something. Smile.

Eric W states that that poly's are difficult to build. He does not address the Boner / Klipsch curved masonite approach. Further,it seems to me that the QRD unts are very much more difficult and pre-made ones are expensive. So if ease of construction and cost is the issues, he has not made a real comparison.

Goodness, those skyline things. Klipsch has one in a listening room. The true QRD units work because of the delays in reflections from the wells. The skylines don't have any wells. How can they be the same thing? It may be true that the oddball shapes diffuse sound a bit and the material absorbs a bit. There is no reason in my mind to think they benefit from the QRD theory. Also, I have not seen any acoustic tests showing what they accomplish.

They seem to me to be sort of fanciful Bauhaus stalactites.

Now, I do respect Winer. but his analysis seems to loose focus; perhaps because of the time limitation. He is giving extreme examples in the youtube and it seems that this is to prove some points which are otherwise difficult.

His demo is to show the effect of diffusers in a recording set up. Actually, I hear some difference in emphasis with his guitar playing and a microphone;, both of them very close to the diffusers. But I don't hear any of them being superiour -- just a little different. Maybe you had to be there.

It does seem to me that he is setting up his extreme situation and saying that it can be extrapolated. Well, maybe so, but how much?.

Art's room is playback situation. In Art's case, all distances are very much greater, the polys are oriented differently.

Let me add that Art may have taken Winer's video as an affront to Art's work. Winer's presentations do not address Art's work at all.

WMcD . .

, .

[artto]

Art's room is playback situation. In Art's case, all distances are very much greater, the polys are oriented differently.

Let me add that Art may have taken Winer's video as an affront to Art's work. Winer's presentations do not address Art's work at all.

WMcD . .

, .

Thanks for your insightful (as usual) input Gil.

Actually, I have used my room for recording and it works quite well. Two of the more memorable times were with banjos. I was recording my friend and his friend a pro banjo player along with another guy on bass banjo. Playing back the tape was uncanny. Between "tracks" when someone started talking on the recording, one of us would turn to answer him only to realize it was on the recording. Another time my friend was recording a duet with himself. Me, my wife and his wife, I guess we got kind of bored and weren't really paying attention when a "BIG" obvious mistake in his playing occured. We all looked up to laugh and point at him only to find him not playing and sitting still on the stool with a big grin as he apparently knew this big mistake was coming up, but of course we thought it was him playing.

Also, I generally have the upmost respect for Ethan and his promotion of the importance of room acoustics and various methods of how to get there. I decided to bring this up not so much because of Ethan's video but because there seems to be an increasing number of people who are putting forth the notion that polycylindrical diffusers are not actually diffusers at all, just simple "reflectors". In some applications, depending on how large (eg: small) and how much bend and uniformity and how many and how they are deployed, I guess one can make an argument for that point of view.

As Don Richards pointed out, many of these same people also have something to sell. I find it interesting that not one of them have actually compared the QRD diffusers to an array of polycylindricals deployed the way they are in my room.

QRD are not without their own problems. From what I've seen they produce very strong lobes. And they also often require greater distances from the diffuser to listener to be effective. In order to achieve broadband performance we still need very large QRD constructions which are complex and expensive to build.

Don't get me wrong, I actually intend to add some QRD to my room. But first I will be turning the polys into huge full-length-of-wall bass traps in much the same way Winer has turned their QRD diffusers into a combo bass trap by adding rigid insulation to the QRD cavities, except in my situation the bass trap cavities behind the polys are 6" to 24" deep.

[mikebse2a3]

Goodness, those skyline things. Klipsch has one in a listening room. The true QRD units work because of the delays in reflections from the wells. The skylines don't have any wells. How can they be the same thing? It may be true that the oddball shapes diffuse sound a bit and the material absorbs a bit. There is no reason in my mind to think they benefit from the QRD theory. Also, I have not seen any acoustic tests showing what they accomplish.

They seem to me to be sort of fanciful Bauhaus stalactites.

Gil the phase grating effect of the QRD work better with walls for the wells is why they are used in those designs. The skyline's wells just don't utilize the walls but the phase grating effect is there. You are correct though in that the skyline is different than the QRD because it is based on a primitive root design principle and one ofit's best features is the supression of the specular reflection. As far as test go even though it appears RPG is no longer making the skyline since it's not listed in their products anymore they should have test data for the design still their I believe.

It is also advisable in many instances to use several periods of the QRD and Skyline devices in arrays to minimize the lobing effect somewhat.

Gil and Artto I would encourage you to explore the RPG website if you haven't. The website has changed since I last visited it but it contains a hugh amount of research and here are just a few searches as an example.

It seems that as more is discovered and rediscovered many things are intertwined in ways we obviously don't fully understand. Check out the poly type arrays and 2 dimensional diffusers they are designing now. See anything that looks familiar to what you have done Artto..?[]

http://www.rpginc.com/verity_search_results.cfm

http://www.rpginc.com/verity_search_results.cfm

http://www.rpginc.com/Technology.cfm

http://www.rpginc.com/verity_search_results.cfm

http://www.rpginc.com/verity_search_results.cfm?kwSearch=phase grating

Also check out what to me is a very interesting PDF that I've attached.

I also believe that the ratio of diffusers to room surface is important to keep in mind. If cost is an issue (when isn't it?) I would probably rather have a higher ratio of less than ideal diffusers than a very limited number of high performance diffusers in many cases.

mike tn

Studio Design From Mono2Surround.pdf

Studio Design From Mono2Surround.pdf

Studio Design From Mono2Surround.pdf

Studio Design From Mono2Surround.pdf

[mikebse2a3]

For anyone interested this is how I am currently implementing diffusers in my current room. The Skylines unique design and how I'm implementing them is a key ingrediant in this room performing much better than it's size would have ever been thought possible by many I'm sure.

http://community.klipsch.com/forums/p/156811/1654985.aspx#1654985

mike tn

[WMcD]

I have almost remembered the book which contains additional information on washboard polys. I remain sceptical about skylines.

WMcD

[Marvel]

Found this calulator for QRD design (free). It might be useful/helpful if one is following this path. The link for DESIGN also had a further link for a QRD technical reference.

Bruce

http://www.subwoofer-builder.com/qrdude.htm

[mikebse2a3]

I remain sceptical about skylines.

Here is a 3D ballon plot for an array of the Skyline.....the response is for normal incidence at 2kHz.

Not sure why your sceptical...have you seen the data and plots for the skyline? Not that data and plots can give you the real experience of the skyline's or any diffusor's performance in typical domestic sized listening rooms.

RPG is heavy into research, development, measurements and standards from all indications that I've seen over the years and if you are interested and haven't read this book by Trevor J. Cox and Peter D'Antonio you might want to borrow this book or the first edition from your library (pretty expensive otherwise).

Anyway for what it's worth I've built and used Polys and QRD style diffusors as well as the ASC Traps and Panels and RPG Skyline products in several rooms. As far as diffusors I like Polys when randomly arrayed/sized/depth and not washboard style(all being the same size/depth) and they are economical especially when the desire is to cover a high percentage of the rooms boundries. I also had good results with the QRD style design with at least 2 periods per unit. The Skyline's are an efficient diffusor over their designed bandwidth and it's performance features are ideal for my present listening room's size and gives me results that I know I couldn't acheive with a typical Poly or QRD 1D diffusor in their place. It's very easy to move the Skylines in and out of my room to demonstrate what they and the placement of them do to improve the listening experience in this space.

Just to be clear I'm not trying to convince anyone into buying or using Skylines but I have found no reason to question their performance as presented by RPG and for my specific purpose I'm not aware of anything that meets my requirements better.

miketn

[artto]

Goodness, those skyline things. Klipsch has one in a listening room. The true QRD units work because of the delays in reflections from the wells. The skylines don't have any wells. How can they be the same thing? It may be true that the oddball shapes diffuse sound a bit and the material absorbs a bit. There is no reason in my mind to think they benefit from the QRD theory. Also, I have not seen any acoustic tests showing what they accomplish.

They seem to me to be sort of fanciful Bauhaus stalactites.

Gil and Artto I would encourage you to explore the RPG website if you haven't. The website has changed since I last visited it but it contains a hugh amount of research and here are just a few searches as an example.

It seems that as more is discovered and rediscovered many things are intertwined in ways we obviously don't fully understand. Check out the poly type arrays and 2 dimensional diffusers they are designing now.

See anything that looks familiar to what you have done Artto..?

http://www.rpginc.com/verity_search_results.cfm

http://www.rpginc.com/verity_search_results.cfm

http://www.rpginc.com/Technology.cfm

http://www.rpginc.com/verity_search_results.cfm

http://www.rpginc.com/verity_search_results.cfm?kwSearch=phase grating

" See anything that looks familiar to what you have done Artto..?"

Yes Mike, I did. Thanks for posting. Proving once again that
those who claim polycylindricals are not diffusers do not understand the
problem, nor the solution(s).

Just some comments of my own:

Regarding “Innovative Integration of Acoustic Treatment Into
Modern Architecture.

Page 6, Classical Diffusion, “Beautiful and
functional, although not as acoustically quantified and optimized as today”. It
may not be as quantified or as optimized, but the real question is, does it
sound better? Or equivalent? Even today, the halls that are widely regarded as
the best acoustics for performing music are all older venues. They are the
Musikverein in Vienna, the Concertgebouw in Amsterdam and Symphony Hall in Boston. There are others of course. But these
three in particular stand out and will generally get no argument from anyone.
They are a reference standard. They also share many of the same characteristics
and sonic signature.

While I have the upmost respect for D’Antonio and
what he is doing, I also believe that at least to some extent, what he is doing
is basically reinventing the wheel, and probably at a nice profit. Good for
him!

IMHO though, optimization, while being a worthwhile
pursuit, if for nothing else than for the sake of knowledge, is also a
double-edged sword. There is in fact such a thing as over-optimization. It is
tantamount to curve-fitting. And curve-fitting is exactly what one needs to
avoid in real world situations. It is akin to data mining. If everything were
always exactly the same, then, of course, there would be no problem. All the
rabbits would happily multiply to the extent that Leonardo of Pisa predicted, all
snail shells would be exactly the same and time would stand still. But they
don’t and they aren’t and the world doesn’t quite work that way.

In “Optimized Canopy Arrays” for instance I
have to take issue with their “Optimization Criteria”. According to their
criteria “The procedure is to place a source and receiver 1m apart on the stage
and calculate the ratio of the early reflected to direct sound energy.
Consequently, it reflects a musicians ability to hear himself and not other
musicians in the ensemble.”

This, IMO is a major problem. It seems to me
to be the wrong criteria. Let me explain. A new concert hall was built recently
at North Central
College, Naperville, Illinois,
Wentz Hall. It seems to have gotten some rave reviews. A couple of my friends
sing in the Naperville Chorus who perform there and consequently I have
attended many concerts there. Contrary to many of the rave reviews, including
my friend’s, I don’t think it’s such a great place. Good acoustics ~ yes.
Great? No.

I recall one “review” where a musician was
sort of trying the place out and said he liked it very much. In fact his
comment reminds me of the optimization criteria mentioned above ~ “it reflects
a musicians ability to hear himself and not other musicians in the ensemble”. I
say this because one of the things I’ve noticed in live performances there is
that musicians and singers, especially soloists, seem to have a problem hearing
each other. While the solo musician trying out the facility for the first time
may have very much liked what he heard of
himself, I have to wonder what he would have thought after a concert with a
full house, or better yet, after hearing himself from several different
locations in the hall. Furthermore, I can tell you that as a matter of fact,
while sitting in the balcony towards the back, soloists often are difficult to
hear, sometimes to the point of being completely inaudible, unless they turn
their head and face specifically in my direction. And these soloists are not
amateurs. The Naperville Chorus typically recruits their soloists from the
Lyric Opera of Chicago so they are very capable of belting it out. This is not
a signature of great hall acoustics. Don’t get me wrong, I’m sure the
acoustical engineer Talaske did the best he could considering the
circumstances. It is leaps and bounds better than Pfeiffer Hall, the
College’s previous main venue. And its one of the nicest places to hear a
concert around here in the burbs. But even the old Auditorium Theater in Chicago doesn’t have the
problems I mentioned here, not even in the worst seats.

In “Optimized Canopy Arrays” they also get into
some far out analogy with genetics and DNA regarding their predictive models. I
haven’t read this depth so I’ll leave that alone for now but it reminds me
of weather and climate forecasting as well as stock price predictions using that
Fibonacci crap. (hint: the word “fib” is in there for a reason)

What I do agree with however, and I too have
been saying this for a long time, after the Conclusions section under Future
Work, they say “In the year 2525, we may have enough processing power (to
include the Towers)”. IMHO we have nowhere near the required processing power
to do the proper analysis to provide such advanced solutions that are actually
equal to or better than what has already been achieved. Much of this is
primarily an advanced intellectual exercise with the use of computers.

To quote one classical music critic who goes by the
pen name of davidsbundler, “if acoustical architects have learned one lesson,
it's that our future lies in the past.” In his article Everything You Always
Wanted to Know About Concert Hall Acoustics (but couldn’t afford the consulting
fee), acoustical engineer Robert McKay (originally with the acoustical firm Bolt,
Beranek & Newman ~ Bolt of polycylindrical and room modes/proportions note in the Klipsch papers) says
"I think all of the acousticians who are designing concert hall facilities
would love to make them sound like the classical halls in Boston and Vienna.” I
agree.

So, in the meantime, I shall rely on basic time
tested principals that are known to produce great, albeit un-optimized results,
with a lot less time, effort and money. After all, in the end it’s what we hear
that counts, optimized or not.

[Deang]

I gave up on diffusers, I couldn't figure out where to put them -- so I started using Confusers.

[mikebse2a3]

Hey artto the rpg site is down at this time but I would like to read the papers you've quoted from.

Anyway if it hasn't been clear I agree with the way PWK recommended the use of polys and the way you have implemented them also. I do believe using them in a washboard style array could create issues and should be avoided. Unless you have identified an area needing improvement then implementing RPG style diffusors or any other treatments types might not offer any meaningful gains.

As far as D'Antonio I believe it's a case of finding new ways to combine, adapt and integrate the "wheels" in ways that are more predictable than what has been available to us in the past. In doing this we gain a better understanding of how things interact and possibly implement this knowledge in better ways.

The brochure attachment (especially note: the shape optimazation page of the brochure) I've posted of the waveform products from rpg shows to me to be basically polys ("The Reinvented Wheel") of 1d and 2d designs whose types are combined in arrays. In this example the goal of a more uniform scattering with sound levels more equal for all the musicians to hear was a goal that was optimized (within the real world constraints of specific architecturel design goal) by their software program. I think this use of optimization is good but must be varified of course by the human ear/brain to see if the program was successful.

I totally agree with you that in the end the success of implementing the acoustical treatments in any given room must be judged on the desired goals for that room as ultimately judged by the human ear/brain.

miketn

Waveform_4 Page Brochure.pdf

Waveform_4 Page Brochure.pdf

Waveform_4 Page Brochure.pdf

Waveform_4 Page Brochure.pdf

[mikebse2a3]

I gave up on diffusers, I couldn't figure out where to put them -- so I started using Confusers.

Hey Dean

It's like walking around in a fog and every so often I'll hit a clearing where the light comes through......I love those moments.![]