Posts Tagged fabric wrapped panels

Demystifying Acoustic Data: Part 2 – Test Material Mounting

For anyone new to the world of acoustics, there is a multitude of terms, coefficients and numbers that are thrown around.  This flood of information can seem intimidating, especially to beginners. In this series, acoustician Cameron Girard of Acoustics First® hopes to help you distinguish between what’s useful and what’s not.

Part 2: How Mounting in Testing Affects Sound Absorption Data

As I discussed in my previous article, the best way to compare the performance of sound absorbing panels is by referencing the Sound Absorption Coefficient (SAC) and Noise Reduction Coefficient (NRC). However, these coefficients are often used as marketing tools. Be on the lookout for companies that list absorption coefficients and NRCs without mention of a particular testing standard or mounting method. It’s vital to check for this information, as direct comparisons to competitors and other materials can only be made if their testing procedures are the same.

The sound absorption of a material that covers a flat surface not only depends on the physical qualities of the material but also on how the material is mounted during installation. The mountings specified in laboratory tests are intended to simulate conditions that exist in normal use, such as direct wall mounting and installation into a ceiling grid.

Many materials for treatment of walls or ceiling are tested using what is called Type ”A” mounting. Type ”A” mounting means the test specimen was placed directly on the test surface of the reverberation chamber. Lay-in ceiling tiles, on the other hand, are often tested using ”E400” mounting. The ”E” designates a sealed air space behind the specimen (simulating  the air gap between a dropped tile ceiling and the structural ceiling) and the number after the ”E” is the depth of the airspace in millimeters. The airspace behind the acoustic material affects the sound absorption by acting as a bass trap. The deeper the cavity behind the panels is, the lower the fundamental of the “trapped” frequencies will be.

To see what this look like in terms of actual numbers, let’s take a look at how different mounting methods effect the sound absorption coefficients of Acoustics First’s HiPer® Panel (a low-profile, composite absorber/diffuser panel).

Since the HiPer® Panel can be used effectively in multiple applications; we had it tested in accordance to the two most-common mounting procedures, Type E-400 and Type A. The results of the laboratory tests are as follows:

Product Info

Sound Absorption Coefficients

Product Name Thickness Mounting 125Hz 250Hz 500Hz 1kHz 2kHz 4kHz

NRC

1″ HiPer® Panel 1″ E-400 0.43 0.28 0.51 0.76 0.99 1.10 0.65
1″ HiPer® Panel 1″ A 0.09 0.28 0.78 0.75 0.94 0.85 0.70

 

As you can see from the chart, the sound absorption coefficient at 125 Hz varies greatly between E-400 mounting (SAC of .43) and Type-A mounting (SAC of .09). If mounting the HiPer® Panel in a ceiling grid, with a sizable airspace, you can expect significant low-frequency absorption, but mounting it on a wall (Type-A) will result in much less absorption at 125Hz.

Other mounting methods are available, but are not used as frequently. Here are some of the basic mounting designations (See ASTM E795 for more information.)

Type A mounting – Test specimen laid directly against the test surface (wall panel on drywall).

Type B mounting – Test specimen cemented directly against the test surface. Type B mounting is intended to simulate acoustical ceiling tiles or other sound-absorptive products adhered to a hard surface with an adhesive.

Type C Mounting—Test specimen comprising sound-absorptive material behind a perforated, expanded, open facing or other porous material.

Type D Mounting—Test specimen mounted on wood furring strips.

Type E Mounting—Test specimen mounted with an air space behind it (dropped tile ceiling).

As we’ve discussed, acoustical data can vary greatly depending on the mounting method used during testing. Acoustics First tries to include as much information about testing procedures as possible, because we feel an informed client makes the best client.

Contact Acoustics First for your all your sound control needs!

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Barrett’s Technology Solutions has a Happy Easter

Sometimes at Acoustics First we get a call from someone who is so knowledgeable that we can’t help but be tickled that they called us to help them.  We received one such phone call from Pete Heskin at Barrett’s Technology Solutions  in Naperville, IL.

Pete and his team were putting together an acoustic treatment for a listening room at their facility and wanted the room’s acoustics to really showcase their lineup of high-end audiophile speakers.  No joke here – these guys have over 50 years of experience in the audio industry – and they keep on the bleeding edge of audio and video.  This treatment is serious acoustic business – and these are some of the most discriminating ears in audio.

Happy Easter guys!

Happy Easter Guys!

Happy Easter Guys!

In keeping with their high-standards and cutting edge approach, they were looking for an acoustic treatment that is as visually stunning as it is capable of treating a room containing some of the world’s greatest sound sources. As you can see, the results are simple and elegant.

The room contains an array of Sonora® panels, Silent Pictures® and clusters of ArtDiffusor® Model D‘s to make this space sound as good as it looks.  (While all of their gear makes the gear junkies at Acoustics First drool…)

So, if you find yourself near Chicago, or on a “Wayne’s World” pilgrimage,  stop into Barrett’s – and if you fancy yourself an audiophile – put your money where your ears are, and hear how discriminating ears listen to music…

… No Stairway to Heaven.

 

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DIY: Super Bass Trap

Take a couple of products and make your corner into a super trap!

decon bass trap explode

One of the most pervasive problems in recording and listening environments is the problem of bass build up in the corners.  If you want to get the most out of your room, try making your corner into a DIY super trap!

Stuff you’ll need:

Simple installation instructions:

  • Use the adhesive to attach the Foam Bass trap to the wall
  • Use the brackets to attach the Sonora® Panel across the corner over the trap

Super simple. Super effective.

As simple as it seems, this method of installing these products is an ideal way to get extra trapping in your corners.  This solution changes the corner density multiple times as the sound waves pass through it –as well as introduces a layer of air space. This installation method takes the strengths of the two products and has them working together to eliminate that build-up of energy in the corners – it literally sucks it up like a sponge!

diy bass trap-top detail
This simple DIY project is provided as a way for our customers to learn better ways to use our products and get more value out of the products they buy.  If you are looking for more ways to use the products you have, look to Acoustics First for Ideas.  http://www.acousticsfirst.com

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Acoustics First Corporation supplies acoustical panels and soundproofing materials to control sound and eliminate noise in commercial, residential, government, and institutional applications worldwide.  Products include the patented Art Diffusor®, sound absorbers, noise barriers, acoustical fabrics and accessories. Acoustics First® products are sold for O.E.M applications, direct, and through dealers.  For more information on acoustical materials and their application, please visit www.AcousticsFirst.com or call Toll Free 1-888-765-2900 (US & Canada).

diy bass trap-front

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Setting the Soundstage: How to treat your home theater like a real theater

Modern AVR’s include all kinds of wizardry for speaker setup, positioning and room equalization. Anyone in the know will tell you that room EQ hardware and software should be a last resort. Correct acoustical treatments will pay much bigger dividends.

If you are like many people, you have recently upgraded your home theater, or you’re getting ready to do so.  During this process you’ve likely learned that the speakers in the TV are sub-par and you should upgrade your audio experience to include an external sound system.  This has become common practice and common knowledge. What you haven’t learned, and which is probably even more important, is how to upgrade the room itself.

One of the things people overlook when trying to make a home theater, is that a real theater pays a lot of attention to the design and treatment of the theater environment. They have good left-right design symmetry (see the diagram for a sample home theater layout).  A good theater also has acoustically treated the space so that people can hear everything that is happening, from anywhere in the theater.  This article will teach you some of the tricks of getting that great big theater soundstage into your home theater.

Bass Traps – the low-down solution.

Low frequency problems are common to almost any room, regardless of size.  The good news is that, most of the time, the solution is simple: put bass traps in the corners of the room.  This is one place where it pays to put a little extra in the budget.  Corners are defined as the intersection of two or more surfaces. There are not just corners at the end of each wall, but also along the floor and ceiling where the walls intersect them.  The more corner you cover with a good trap, the better bass response you get – it’s that simple.  Bass loves the corners, and by putting bass traps there, you keep the bass crisp and natural.  If bass frequencies are allowed to build in the corners, it causes the bass frequencies to become muddy and undefined – trap them.

Some bass traps work double duty as broadband absorbers as well, which can keep your costs down when considering covering a bunch of square footage with absorbers. Bass traps alone can solve many problems in your room, and due to the simplicity of the implementation, I recommend you start with these first – at least fill the four main corners.

Foam works. But this is a theater, not a studio.  Fabric wrapped absorbers look as good as they sound, and Geometrix™ by Acoustics First, fit the corners like a glove.  Pick a fabric and get some quarter rounds to fill your corners – that’s it.

Broadband Absorption – tame the ring.

Another common problem in home environments can be easily verified with a clap test.  Go into your room and clap your hands.  Most likely you will hear more than just the initial clap.  Depending on the severity of the problem, you will hear a flutter, ring, or echo after the initial *pop*.  This is caused by the sound waves bouncing around off the hard surfaces of the room and returning to your ears after a delay – the more times they bounce without losing energy, the longer the delay. The best way to remove energy from these waves is to use broadband absorption, but where do you put them?

More than likely, your TV and sound system are going to be in a fixed position, and your listening position will also be fixed – so the early reflection surfaces should be easy to locate.  You will need a friend for this activity, a mirror, and a pencil. Have your friend place the mirror flat against the side wall and move it around until you can see the speakers in the reflection from your seat – then mark the wall. This is where you are going to place the absorber. The diagram shows a good place to start looking for these reflection paths. Repeat this for all the walls from all the seats. 

What you are looking to create is a reflection free zone, which basically means, wherever the sound could bounce off a surface and get to your ears, we are going to absorb energy from it.  You can spend a good deal of time on this, but this is the only step that requires this time and effort, so make it count.   Sound travels in all directions from the speaker, including behind it, so put absorbers behind it on the wall. Don’t forget the floors, ceiling, and the wall behind you – sound will bounce off those as well. 

This simple process will show you where you need to treat.  Hang broadband absorbers over all the early reflection points – left, right, front and back.  Absorber clouds should be hung on the ceiling, and place a nice thick carpet on the floor.  Placement is the first key to getting this reflection free zone.  The second is the right choice of absorber

To match your fabric wrapped bass traps, the simple choice is get some more panels wrapped in fabric. The Sonora® line of broadband absorbing panels coordinate with the bass traps, and come in a plethora of sizes and mounting options to work in your space.  Need 2’x4’ behind the speakers, 4’x4’ on the sidewalls, 2’x6’ on the back wall, and a 2’x6’ ceiling cloud – all in material that match those bass traps? Done.   

Finally, use broadband absorption with caution, specifically using too much.  If you plan on covering more than 50% of your walls with this stuff, you’re going to notice a muffled almost claustrophobia inducing deadness.  We are not trying to suck the life out of the room.  We are just trying to take enough energy away from those early reflections to keep the focus on the initial sound produced by the speakers.

Diffusers – put life back into your space.

The steps we have taken up to this point have been using absorption to control excess energy that can have an adverse effect on the listening environment.  We have removed the unwanted direct reflections and we have tamed the bass, but there is something more we can do to give life to this room – diffusion.

Diffusion will give us something we couldn’t attain through absorption – a sense of open space.  Even after treating with absorbers, there are still areas of the room where sound waves will sit, because your room is a fixed box with fixed speakers.  Diffusers scatter the energy, creating ambiance with residual energy, like sitting quietly in a forest – the energy around you being directionless, omni-present, and spacious.  This simple step does not remove energy from your room, but redistributes it into a soundscape that can make you forget you are in a room at all.

There are many ways to diffuse the sound and coordinate with your room, from the fabric covered HiPer™ Panel and Double Duty Diffusers™, to the striking line of Art Diffusors® like the Model C, which can be painted to match your décor. 

Advances in acoustic treatments are being made all the time, bridging form with function, creating products as visually stunning as they sound – and helping your theater, or any theater, be the best that it can be. So use these tips to set up your home theater like a real theater, and experience the difference a soundstage upgrade makes.

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Acoustics First Corporation supplies acoustical panels and soundproofing materials to control sound and eliminate noise in commercial, residential, government, and institutional applications worldwide.  Products include the patented Art Diffusor®, sound absorbers, noise barriers, acoustical fabrics and accessories. Acoustics First® products are sold for O.E.M applications, direct, and through dealers.  For more information on acoustical materials and their application, please visit www.AcousticsFirst.com or call Toll Free 1-888-765-2900 (US & Canada).

 

The complete article is posted at the following link:  http://acousticsfirst.com/article-setting-the-sound-stage-how-to-treat-your-home-theater-like-a-real-theater.htm

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Sonora® Acoustical Wall Panels named Christian School Products Top Product 2012

Sonora® Acoustical Wall Panels are the premier choice for reducing reverberation and improving speech clarity.  Available in many sizes and colors, these absorbers are suitable for many applications. This includes offices, worship facilities, schools, gymnasiums, museums, auditoriums, or any application that requires an acoustical solution.  Visit www.AcousticsFirst.com for more information.——————————————————————————————————————————————-

Acoustics First Corporation supplies acoustical panels and soundproofing materials to control sound and eliminate noise in commercial, residential, government, and institutional applications worldwide.  Products include the patented Art Diffusor®, sound absorbers, noise barriers, acoustical fabrics and accessories. Acoustics First® products are sold for O.E.M applications, direct, and through dealers.  For more information on acoustical materials and their application, please visit www.AcousticsFirst.com or call Toll Free 1-888-765-2900 (US & Canada).

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