Posts Tagged noise control
There is a saying in our industry: When it comes to designing a space, acoustic consultants are blind and architects are deaf. In reality, it is in both parties best interest to consider the other side when designing a space, so visual form meets acoustic functionality.
Let’s be real, standard acoustic treatment is far from sexy. Typical 2’x4’ panels, while fully functional, don’t present the architects with much in terms of visual interest. This is where Acoustics First can supplement the design goals of the architect/interior designer with our technical expertise to find a custom solution that sounds and looks great.
Recently, Acoustics First® was asked to provide the custom panels for the cafeteria at Kramer Middle School in Washington DC. It was settled that hexagonal ToneTiles™ would be suspended as clouds in a geometric pattern around the ceiling. The resulting “honeycomb” effect is not only visually appealing, but the treatments effectively cut down the overall reverberation; increasing speech intelligibility and making the space more comfortable for a variety of activities.
Acoustics First® enjoys the inherent challenge in making these custom panels a success. We have plenty of experience in fulfilling the design goals of architects and interior designers. Interested in seeing more of these custom projects?
Visit http://acousticsfirst.com/installations-education-school-museum.htm to see some more examples.
Feel free to give Acoustics First® a call to discuss your custom treatment needs!
Since it’s been a while, I have received approval to write about phones and scones – yummy! Oh, I misread that… I can talk about phons and sones? Oh boy. I mean… hmm… uh…
Every so often, you get exposed to a term that you’ve never heard; it seems like someone just made it up – and the more you learn about it, the more made up it seems.
(Disclaimer: I swear I didn’t make these up.)
Today, I will introduce you to two of these amazingly real terms, and do my best to explain why these terms exist… prepare to be amazed!
OK. Phons and Sones are two related terms in Psycho-acoustics that refer to how humans perceive the “LOUDNESS” of sounds. These are actual real concepts. (Stop laughing.)
Don’t we all perceive sound differently? YES!
So how can you have an actual measurement based on something that everyone perceives differently? EASY!
Take a bunch of people.
Play a 1Khz sine wave.
Play another frequency.
Ask them if it sounds just as loud.
Repeat. (No kidding.)
OK, this is over simplified… Let’s start by setting some rules that make this a little easier.
For reference – whatever dB level that 1KHz wave is will be the reference for the whole group… compare a bunch of frequencies at different levels to 1Khz at 40 dB – and we’ll call all the ones that sound just as loud the “40 PHON Equal Loudness contour.”
Why? Because they sound just as loud as the 1kHz wave at 40 dB. (I’m not joking!)
Then compare a bunch to a 1KHz wave at 50dB and call all of those that sound as loud, (wait for it)
the “50 PHON Equal Loudness contour.”
Then 60dB, 70dB, 80dB… etc (see a pattern?)
Now, plot all of these from a bunch of people who hear pretty well… take an average and WHAMMO!!!
The PHON Equal Loudness contours!
(To be fair this is the data from a bunch of 18-25 year olds who still have reasonably good hearing…)
Remember this is PERCEIVED LOUDNESS. The average of what the test subjects said “yeah, uh, that’s just as loud, Dude.”
It seems strange doesn’t it – that these aren’t nice straight lines? That’s because the human ear is constructed in such a way to be more sensitive to certain frequencies than others.
So according to this chart – a 1KHz wave at 40 dB sounds just as loud as 125 Hz at ~60dB and 3150 Hz at ~35 dB. (All on the 40 Phon contour.)
That’s Psycho-acoustics for you. (Wow.)
So if you’re an average person with average hearing, your bass perception is terrible and over 16KHz you’re basically – well… deaf.
But you hear really well from 2kHz – 5kHz!
Anyway… what’s the point?
Phons measure how loud the human ear perceives sounds at different frequencies. (TADA!)
FINE! – then what are Sones ? To make this simple – Sones are relabeled Phons.
You start with 40 Phon being 1 Sone then double it every 10 Phon.
40 Phon = 1 Sone.
50 Phon = 2 Sones.
60 Phon = 4 Sones.
70 Phon = 8 Sones.
80 Phon = 16 Sones
90 Phon = 32 Sones
100 Phon = 64 Sones
(Hmm, thought that would be more complicated? It is – but that’s basically it in a nutshell.)
You will almost never see a phon or a sone. Bathroom exhaust fans and blowers are sometimes rated in Sones – to let you know how quiet they are… The problem is that no one actually knew how quiet that was until now!
I guess it sounds better to say –
“This bathroom fan operates at only 2.5 Sones!”
…Than it would be to say…
“This bathroom fan resonates at over 80dB,
but it’s in a frequency range that humans don’t hear very well,
so it sounds quieter than it actually is… no… really!”
Human perception of sound is very important to the development of acoustic products – Psycho-acoustics are not a joke.
(Why are you still laughing?)
Airflow is good. Circulating stagnant air has many health benefits, but what do you do when that ceiling fan is just making too much noise?
To start, check all the normal suspects; is it balanced, cleaned, level, blah blah blah… You’ve probably already checked these anyway. It’s an older fan, the motor hums, because older fans hum. If it’s vibrating through the structure, there may be something you can do to isolate that extra vibration – and at least keep the other occupants happy.
When most people think of Vib-X pads, they think of a musical function; Isolate your speakers, isolate an amplifier, isolate a (insert name of miscellaneous musical gear here)… but there are some really useful everyday functions for this wonderful material. Like keeping that fan from vibrating the entire house!
The simple install may involve a contractor, or at least some one who knows electricity, so you don’t electrocute yourself… but after shutting off the power to the fan, it’s pretty quick. Take down the fan and find the box. Disconnect the box. Cut some Vib-X to separate the box from the wood. Cut some Vib-X squares to use as washers. Remount the box using the diagram, a couple fender washers, maybe a couple optional grommets if you desire – then re-install the fan.
Ceiling fans are usually mounted to an electrical junction box in the ceiling, which is usually just screwed to a ceiling joist or some simple wooden frame. By using the Vib-X to isolate the electrical box from the wood, the vibrations do not directly transfer from the fan into the structure of the house, turning that old, vibrating ceiling fan – into a breath of fresh air.
Simple. Thought so. Don’t forget to balance, level, and clean that ceiling fan while you’re doing all this. Turn that power back on and enjoy the breeze.
That’s right. Acoustics First will be unfurling some of the wrapping and exposing the newest addition to the ArtDiffusor® Family of diffusers… the Model D. Where can you see it?
September 25-26th, 2013
Walter E. Washington Convention Center, Washington DC
Acoustics First will be set up in the main exhibit hall (in Booth 507), showing off the Model D, the newest release into the ArtDiffusor® family. Come on down to see for yourself what all the noise is about – pardon the pun.
Another interesting development is the first install of Model D’s in a Broadcast studio. In a move to “liven-up” the very “dead” studio to better accommodate the live recording of in-studio musicians, WBWV 88.7 FM in Beckley, WV pointed to the New Model D as their solution.
- How diffusion works Video.
- Photo Gallery
- Early “Alien” promo video
- Model D Pattern Designer
Posted by Acoustics First in Auditorium, Broadcast Facilities, Classrooms, Diffusion, Home Entertainment, Home Theater, Media Room, Multipurpose Rooms, Music Rehearsal Spaces, Music Tracking Room, Recording Facilities, Recording Studio, Studio Control Room, Teaching Rooms, Teleconferencing, Uncategorized, Vocal Booth, Voice Over on July 4, 2013
Four score and seven years ago (1926), movies had just begun integrating sound along with the visuals, as Warner Brothers released Don Juan – syncing a 33 1/2 rpm audio disc to the video as part of the new Vitaphone system. The era of talkies had arrived, as did a new era of fake accents.
While we still have those fake accents from the days of yore (and Johnny Depp as Don Juan), we have new technologies to bring us our entertainment – high-definition video on big screens with 10.2 digital surround sound, playing in home theaters that rival the best public theatrical venues.
While we have seen (and heard) the technological evolution of movies to what they are today, we have also seen (and heard) the evolution of acoustics – and the one area I’m going to discuss today is one of the fastest evolving acoustic disciplines – Diffusion.
Diffuser design has come far from the early days of scattering sound by changing the angle of your wall, or the shape of the room to negate, dilute, or diffuse unwanted or undesirable acoustic waves. Today, acoustic diffusers are mathematical and scientific wonders, designed to be elements that are inserted into your listening environment to create an acoustic space that is open and airy.
During this evolution of diffusion we have seen the rise of many shapes; The Pyramid, the Barrel, the Binary Arrays, Flat Panel, 1D and 2D QRDs, and more… a veritable cornucopia of geometric shapes and mathematically produced profiles, which are scientifically sound, but fundamentally, inorganic.
The notes on the instruments we play, are based on math and physics, but the music we play ebbs and flows from the pounding of drums to the smooth bass lines, from the intimate vocals to screaming, and from the heavy metal acts to classical symphonies (with or without a heavy metal act). Diffusers have followed suit, changing their shape along with the changing industry – making advances as new discoveries are made.
Diffusers have become important acoustic treatments in listening rooms, recording rooms, sound stages, and theaters – embrace the diffusers! Embrace the future Don Juan’s and their terrible accents… ok… just diffusers… fine.