Archive for category Diffusion

ArtDiffusor® Model C vs. Aeolian®: Similar, yet different.

Art Diffusor Model C vs. Aeolian Sound Diffuser

For this installment of “Similar, yet different” we look at The ArtDiffuser® Model C and the Aeolian® Sound Diffuser.

While these two diffusers look very different, there are a fair amount of similarities between them.  Their physical size and depth allow them both to be great mid-frequency diffusers, but did you know that the Aeolian® started life as a blocky-looking diffuser – just like the Model C?  It’s true!

ArtDiffusor® Model C array on a hanging bass trap.

The mathematics behind the two diffusers is similar, but the implementation is different.  While the Model C retains its “blocky” appearance, the Aeolian has run through a mathematical process called “bicubic interpolation.”  Without turning this into a math-heavy post, if you take a “blocky” design like the Model C and run its geometry through bicubic interpolation, you get a “curvy” surface like the Aeolian® – It “smooths” the transition from one block to the next in a 3 dimensional matrix.

While they did not begin as identical geometries, they were similar in their height ratios – with the Aeolian® starting with fewer blocks in a more random distribution, and a slightly taller maximum height.  They both effect similar frequency ranges, with the Aeolian® going slightly lower and higher due to its depth and interpolated surface.  The pattern and type of the diffusion is also different because of the different geometries – the Model C has blocks, and the edges of those blocks introduce a great deal of edge “diffraction” – which is what happens when a wave interacts with an edge, or corner, of a surface. It bends and shears around the edge, which helps break up the continuity of the waveform, where the Aeolian® takes the approach of redirecting most of the energy off a randomized and continually-curved surface.

Aeolian® Diffuser array on the back wall of Big3 Studios.

It is important to note that the two are similar, yet different in their absorption numbers as well.  With the Aeolian® being deeper with a single large cavity, it provides a bit more absorption in the low frequencies than the Model C, which is a more rigid geometry containing smaller elements.  Depending on the space, this may be a useful addition to the diffusive properties.  While some spaces need the extra absorption, some are pretty well balanced already and are just looking to “sweeten” the sound a bit.

On the surface, they are both a nominal 2’x2′ square of thermoformed Class A plastic with lightly textured surface.  That is the extent of the visual similarities, and we cannot hide the aesthetic differences between the two devices. The ArtDiffusor® Model C is a “classic” diffuser.  Many have been looking at these for the better part of 3 decades now.  It’s a classic design at this point with no need for introduction – it is what the quintessential diffuser “looks” like.  In fact, when many people think of a diffuser – the Model C is what they visualize!  The Aeolian® is a modern rendition of the classic design. Using modern calculation techniques, we can now present the type of diffusion the Model C is famous for, in a different way.

While the two geometries look entirely different, and perform a bit differently, they have a common heritage as mathematical, 2-dimensional diffusers.  You could say that the Model C is the grandparent of the Aeolian®, and that pedigree has been passed on – having a similar foundation, but a different final interpretation.

 

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ArtDiffusor® Model C and Model F – Similar, yet different.

Model C vs Model F

We often get asked about the functionality of the different diffusers, and one of the frequently asked questions is about the differences between the ArtDiffusor® Model C and ArtDiffusor® Model F.  We will cover some of similarities and differences in the design, functionality and use of these two devices.

Design.

The Model C and Model F use identical math to come up with their basic structure, they even have angled faces – the main difference between the two is that the Model F elements are ½ of the Model C’s height, length and width – and then it is duplicated 4 times in the same footprint…  The Model C is nominally 2’ x 2’ x 4” deep.  The Model F is four quadrants that are nominally 1’ x 1’ x 2” deep – like little scaled down Model C’s… This makes them visually similar and aesthetically compatible.  This low profile design makes the Model F more desirable for ceiling installs in spaces with very limited headroom – like basement studios that have low ceilings.

 

Performance

Due to the different size of the elements on the two devices, they have very different frequencies at which they are most effective.  The Model C is a mid-frequency diffuser by design… having larger elements and deeper wells than the Model F.  The Model F is primarily a high-frequency diffuser, due to the small elements and lower profile.  Both diffusers are tuned to different frequencies as their “primary range,” and while they do affect lower and higher frequencies than they are designed for – it is to a lesser degree, or the product of absorption.

What does this mean?

The Model C has a primary design range of 1KHz to 4KHz.  This is where it is primarily designed to work.  It can and does diffuse below 1KHz and over 4KHz – just to a lesser degree than its primary design range.

The Model F has a primary design range of 2KHz to 8KHz, and again, it does diffuse outside of that range, but to a lesser degree.

The angled caps of both the Model C and Model F help to extend their high frequency range by reflecting sound in different directions at higher frequencies – causing the sound to scatter spatially.  The different heights of the elements cause sound reflections to be offset “temporally,” or in time. The sound that hits the higher elements is reflected sooner than the sound that hits the lower elements – travelling further before it is reflected.   This time offset, changes the “Phase Coherency” of the reflection; the larger the difference in the heights, the greater the offset in time.

The size of the elements matters as well. The shorter wavelengths of high frequencies can diffract and scatter off of the smaller elements of the Model F more readily than low frequencies, which see the Model F as a slightly angled & mostly flat surface. However, the lower frequencies are more affected by the larger and deeper elements of the Model C.

How do these differences help define their use?

The Model C is a great all around diffuser – it covers a wide range of frequencies, throws a very predictable 2D diffusion pattern, and it is tuned to a very musical range.

The Model F is a great high-frequency diffuser.  It targets a few very specific, yet important issues.  High frequencies are responsible for some nasty problems in rooms.  Flutter echoes, ringing, comb filtering, and other artifacts are particularly noticeable in higher frequencies.  If your room is otherwise performing well acoustically, the Model F can help tackle that last hurdle to make a good room into a great room.

Model F and C

Many critical listening environments use both the Model C and Model F to tune the diffusion in their space.

 

While the white Aeolians® on the back wall are the visual focal-point on in Big3 Studio A, look closely at the ceiling and you will notice a large array of black Model C’s and Model F’s. These help to intermix the diffusion of different frequencies in the large control room.

Due to their aesthetic and functional compatibility, many rooms benefit from using both.  Model C’s addressing the bulk of the Mid-range diffusion, and the Model F smoothing out the top end.

I hope that this highlights the unique properties of both the ArtDiffusor® Model C & ArtDiffusor® Model F – and helps to demystify their function and use in your space.

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DIY – Nouveau™ Home Theater Back Wall

It wasn’t a difficult install, but these Nouveaus made this space sing.

Adding Nouveau wood diffusers to a home theater is not as daunting a task as it may seem, and can be done with a little planning and a few tools.  This install used an ingenious mounting method to ease the final install.  Instead of mounting the z-track to the wall directly, it was mounted to sheets of plywood which were hung with Gorilla/Hercules hooks.

The first task was to pick a stain. You can use the back of a plank to get an idea of how the poplar will respond to the different options.  Poplar has a very interesting and varied structure that will take stain differently than some other woods. Darker stains may be more consistent, but don’t reveal the character and variation in the wood.  This install chose a Smoke Gray which grayed out soft areas and browned the harder heart wood. A semi-gloss clear coat was used to finish.

Using the back of the Nouveau, you can see how the stains will “take.”

While the stain dried, the mounting plywood was cut down to hide behind the planks. Four hanging straps with eye-loops were then added to the top edge of each of the plywood sections, and spaced to avoid studs.

Industrial hanging eyelets were added to the top edge of the sheets to make them easy to level and hang with the Gorilla Hooks.

The Z-track that would normally be installed on the wall was installed on the opposite side of the plywood.  This will make it easy to hang the Nouveaus onto the sheet after it’s on the wall.

Z-Bar track was added to the top and bottom of the plywood sheet to accept the z-bars that are going on the back of the finished Nouveau planks.

After the Nouveau planks are finished with the staining, and left to cure for a few days, they are ready to have the mating Z-bars attached to the back.  They are installed with the same spacing as the Z-tracks on the plywood sheets.  This will make it easy to align them after the plywood is hung on the wall.

The z-bars are measured, marked, and installed at the same spacing as the z-tracks on the plywood.

The Gorilla/Hercules Anchor hooks are rated to around 50-60 lbs each. The Nouveau planks are roughly 25lbs each (at 48 inches) and each section has 4 hooks supporting 4 planks plus the weight of the 3/8″ plywood.  The hooks are installed so that the plywood will hang level – with the weight distributed evenly across all four hooks.

When installed properly and leveled, each of these hooks will hold up to about 50-60lbs each. In this configuration, they should only need to support about half that.

Finally, the Nouveau planks are installed into the Z-Tracks on the plywood, and moved into position.  Because the z-bars were installed square and level, there is no shifting, and they hang true.  The undersized plywood sections disappear behind the planks leaving the impression that the planks are floating slightly off the wall.

The install doesn’t look much different from a direct mount z-track installation, with a small gap against the wall.

While this mounting method may not be ideal for every scenario, this was an effective way to install 8 Nouveau™ planks with only 8 small hook holes in the wall.  These can now be installed in apartments or temporary environments with minimal damage to the existing walls – and once you are done, they’re easy to take down and reinstall somewhere else. You just need a level!

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Art Diffusor® Nouveau™ – Limitless possibilities.

ArtDiffusor® Nouveau™ on a wall with a dark stain – framed.

Hey! Here’s another installation of our new ArtDiffusor® Nouveau™. For this install, these four boards were not only stained, but also framed out to enhance the design aesthetic.  From different paints and stains, to mounting techniques, there are limitless possibilities for customization to create your own unique and functional sound diffusing arrays.

ArtDiffusor® Nouveau™ on a wall with a dark stain – framed.

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Make your voice heard! – Treating your home office for conference calls.

The current crisis has forced a large portion of the workforce to operate out of their homes. Daily Zoom and Skype meetings have become a ubiquitous part of our lives. For many of us, this shift is only temporary. However, some companies are seeing the benefits of working at home, and are making plans to move employees to permanent remote positions.

Teleworking Offices can benefit from acoustic panels like the Silent Picture® Panel, which reduces reverb and flutter echo, while appearing to be a piece of wall art.

I’m sure all of you have been on a conference call in which a team member’s audio is difficult to understand. This could be caused by a microphone or connection issue, but a large number of intelligibility problems are rooted in a room’s acoustics. Let’s take a look at some common acoustic issues in home offices and how they relate to conference call clarity.

Background Noise – Obviously, it’s difficult to understand speech when there is a lot of background noise. It is vital that you isolate yourself from extraneous sound sources as best you can. Some sources (TV, HVAC) are easier to control than others (traffic noise, pets, children etc.). Make sure your office is “closed off” from intruding noise. Remember, sound is a little like water; it will “pour in” through any openings, such as gaps around doors. If possible, install full perimeter seals and door sweeps to improve sound isolation in your office. If you have sound transmitting through a wall, ceiling or floor, you can consider adding a layer of mass loaded vinyl to the assembly in order to help block unwanted air-borne noise. You can then cover the mass loaded vinyl  with SoundChannels® like in this blog.

Reverberation – In simple terms, reverberation is the sound energy that remains in a listening environment as a result of lingering reflections. The reverberation time (RT or RT60) quantifies how quickly an impulse sound decays in a space. Reverberation time is dependent upon the volume and surface materials of a given room. Large spaces with hard materials (tile, drywall etc.) have longer reverberation times, while small rooms furnished with “softer” materials (carpet, drapes etc.) sound more much more “dead”. Speaker phone conversations require a very short reverb time, for optimal clarity, somewhere in the .5s range (half of a second). You can reduce reverberation in your home office with the addition of “fluffy” or irregular furnishings, acoustic panels, rugs, curtains and plants.

Flutter Echoes – Flutter echo, which can be heard as an annoying “ringing sound”, is caused by parallel reflective surfaces. In certain critical listing environments, sound diffusers are used to alleviate flutter echo. Flutter echoes can greatly degrade conference call clarity. This phenomenon can occur between two walls or floor-to-ceiling. To control flutter echoes in your office, you should break up any parallel surfaces with furnishings and/or sound absorptive treatment.

Silent Picture® Tone Tile® and Sonora® Panels are all great ways to attractively incorporate sound absorption into your work space!.

Reach out to Acoustics First® for a treatment recommendation for your home office!

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