Commissioning Audio-Visual Systems | Why it’s Essential
This past summer I went to commission a small sound system at a new facility. Not necessarily a big expensive project, but the client had hired us to commission the final installation and make sure everything was installed as specified. I showed up on site, confirmed all of the equipment was installed and then proceeded to check out how the wiring had been installed. At first everything looked pretty good, until I pulled one of the microphone input plates off the wall and discovered that there was no junction box behind it. Instead someone had busted a hole in the masonry block and tried to fish the wires down through the block from above. But they had run into a little problem at the steel beam. So they made another hole through the vapor barrier and ran the wires just inside the exterior brick. Problem solved, right? Uh… not so much. (more)
Collaboration – The New Buzzword in University Acoustics
The education methods used in today’s universities are rapidly changing, and as the methods change, so does the architecture. The big buzz right now is creating “collaborative spaces for learning“. Traditional push down models of teacher-to-student lectures are being supplemented by a new focus on interactivity and, there’s that buzz word again, collaboration. So what are the acoustical challenges inherent in the new system? (more)
Gymnasium Acoustics | The Multi-Use Problem
Gymnasiums often end up being multi-use spaces. Of course, they are used for competitive sporting events, for team practice, recreation, and for Phys Ed classes. But they are also used for school addresses, commencement ceremonies, band and choir concerts, and more. Those with stages are used for musicals, plays, and speaking events. I have been asked to help mitigate acoustical problems more often in gymnasiums than in any other type of school space; possibly more often than in any other type of space, period. And there are almost always two complaints that I hear… (more)
Why Your Conference Room Technology May Soon Be Obsolete: Part II
As the VGA connector continues its rapid transition towards obsolescence (referred to in Part I of this post) many people simply assume that using adapters (such as HDMI to VGA) will solve the digital-to-analog connectivity problem. While this may work in the short term, it ignores the looming problem of DRM (Digital Rights Management), a way of encrypting new media to protect against copyright infringement. DRM uses something called HDCP (High Bandwidth Digital Content Protection) to control which devices are allowed to receive the video signal. So how will you know if you’re using digitally protected content? Well, for starters, your adapter will just stop working. (more)
Psychoacoustics: Transient Noise Grabs Attention
Have you ever noticed how some sounds catch your attention and others do not? For example, you are driving down the road thinking of your plans for the day and all of a sudden you hear a squeak in the dashboard. It draws your attention immediately, while the air conditioning fan likely does not. The squeak is intermittent (and likely tonal, but that’s a topic for another blog) and therefore stands out over the more constant sound of the fan. This reaction is similar to vision, where our attention is drawn by moving objects much more so than stationary ones. (more)
Why Techies Buy Audio-Video Gear Online
My church recently decided to upgrade from our old analog mixing board to a brand new digital mixing console. The interesting part of this process was that they did not buy it through a local AV contractor. They purchased the sound board online through a company that specializes in phone and internet box sales. This got me thinking about the trend over the past few years in which more and more Audio Visual end-users purchase equipment from online sources instead of the local dealer or shop. Is this a good thing or a bad thing? And why is this becoming the norm? (more)
The Speaker Shootout at High Noon
Question: How do you assure your client that they are getting the best possible speakers for their Auditorium or Fine Arts Center? Answer: You hold a “speaker shootout”. Recently one of our clients was in this exact situation, so we did just that. We invited several manufacturers of line array speakers to show up, all on the same day, so we could let our client hear the differences in sound quality back and forth in the exact same auditorium they would be installed in. Three different manufacturers arrived, speakers in tow, to hang their line arrays for the shootout. As the client’s AV Consulting Firm, we were there to moderate the shootout and ensure that each manufacturer got a fair shake (clean signal, volume levels, sound power levels, and so on). And then we began. The client had arranged for a group of about 20 listeners and key decision makers to join us for the shootout as a virtual “jury” to help decide which speakers to purchase. May the best speakers win! (more)
Why Your Conference Room Technology May Soon Be Obsolete
You can’t get away from the digital age. It seems like digital technology is everywhere. As Audio-Video designers, the march towards all things digital is having an impact on display technologies as well. Meanwhile, flying under the radar, there is a subtle shift happening in how the average person shows information from a computer onto a projector or display. (more)
The Problem with Pulpers | Noise and Vibration Control
We were recently called in to assist in addressing a noise issue that was the result of a university’s desire to be more “green”. In this case, we were asked to assess the noise produced in the dish wash room of a university student union. This blog is the second of a two-part post about student union acoustics, and you may want to read the first blog on College Campuses and Student Union Acoustics before continuing. (more)
If It Sounds Like Noise to You, It May Be “Esion”
Fundamentally, sound is “that which we hear”. What we hear at any given time can greatly influence us. We use sound to communicate, to express warning, fear, pleasure and excitement. Some sounds can relax us and help us fall asleep, while other sounds can distract us and make it more difficult to perform simple tasks. Different sounds can be soothing and pleasing or annoying and irritating. Accordingly, determining “What is sound?” and “What is noise?” can become a highly subjective task. As engineers and scientists, it’s our job to generate generalized models that have a high level of correlation to humans (or to specific populations). (more)
When One Size Does Not Fit All | Diffuser Sound Levels
On a recent trip to India, I discovered a cute clothing sizing term called “free size” which is equivalent to “one size fits all”. Free size clothing must be a manufacturer’s delight since production and distribution are greatly simplified. Adjustments to the size of the garment are typically made through waist ties of various designs and if needed, permanent alterations.
In the A/E/C industry, diffuser, grille and register (air device) manufacturers have chosen the free size philosophy when it comes to providing sound data. (more)
White Space Update for Wireless Microphones
Several months ago (10-13-08) I wrote about the current state of the wireless microphone frequency spectrum and how the actions of congress and the FCC are shaping the future of wireless technology. Well, several notable updates and changes have been made since that time. You may recall that February 17, 2009, was the date set for the transition to DTV (Digital TV). Congress (in all its wisdom) decided that it would extend the deadline to June 12, 2009. (more)
The Leaky Bucket | How Sound Escapes
Blocking sound is often analogized to plugging the holes in a leaky bucket. If you plug up all the bucket holes except one, the bucket is still going to drain. In acoustics, an outstanding partition design will not adequately block sound if holes and weak spots exist where sound can find its way through. (more)
College Campuses and Student Union Acoustics
At Acoustics By Design, we regularly consult on the design of College and University buildings including classroom buildings, dormitories, athletic facilities, performing arts buildings, libraries, research buildings, and student centers. These numerous building types result in our needing to address a myriad of acoustic and vibration issues. Many student centers and student unions face a similar problem: loud noise from the commercial kitchens inhibit the relaxed social environment for the students. Universities want their student unions to be a center for campus life and activity, and if the student center is too loud to provide the desired environment, students will inevitably congregate elsewhere. (more)
How LEED V3 Changes Everything
It’s official! The all new LEED Version 3 has been launched by the U.S. Green Building Council. The new system makes several big changes that affect everyone from architects and engineers to builders and building owners. This information is especially important if you are working on a LEED project or if you are a LEED Accredited Professional. Here are some of the initial updates at a glance: (more)
How Green Design Can Save You Some Green $$$
It seems like every project that comes across my desk has a stated goal of attaining some level of LEED Certification (LEED Silver, Gold, Platinum, whatever). We’re talking K-12 schools, universities, healthcare facilities, churches – they’re all “going green.” But how much does all this stuff cost? And can green design really save you some green $$$? (more)
Elbows vs. Sound Attenuators: Interchangeable?
It is common belief that a series of elbows near an air handling unit (AHU) can accomplish the same insertion loss as a manufactured duct sound attenuator. It’s true that elbows are less expensive than sound attenuators, but what acoustical performance is really achieved with this “low cost” substitution?
Let’s compare the two designs. Using the tables presented in the 2007 ASHRAE Handbook – HVAC Applications, for any type of elbow (round, rectangular, acoustically lined or not), the width of an elbow (in the plane that it turns) must equal or exceed 30 inches to get ANY insertion loss at 63 Hz. A 30 inch wide elbow provides only 1 dB of insertion loss (IL) at 125 Hz . These two frequencies are typically of concern when reducing sound from AHUs.
It’s time for another semester, and I tell my architecture students that if there’s one thing they learn in my acoustics class, it’s that porous absorbers do not block sound. A porous sound absorber, by definition, has many tiny interconnected voids that sound travels through. Fiberglass and open cell foam are examples. The sound wave loses its energy through friction between the air particles and the fibers/void walls of the material it is passing through. (more)
4 Basic Concepts for Corporate Board Room Video Conferencing Systems
It’s January, and that means new budgets for companies that operate on the calendar year. If this year is anything like the last, it means we will be receiving calls from companies inquiring about corporate board room video conferencing systems. As AV Consultants, one of the most common questions we get asked is, “What do other companies have for AV equipment in their Boardrooms?” And the follow up question is always, “Should we be looking at a video conferencing solution?” It seems, in the business world, everyone is concerned that if their technology is behind the curve, then they won’t be as competitive. And we are all concerned about how these new technologies affect our bottom line. But believe it or not, video conferencing may be a viable and cost-saving solution for almost any company that seeks to enhance its communications. (more)
Decision 2008 – White Space Disaster for Wireless Mics
Last Tuesday, while many of us were casting our votes in the presidential election, the Federal Communications Commission (FCC) was making a landmark decision of its own. On their private ballot was a proposal to open the so-called “TV White Spaces” of the frequency spectrum for expanded use. And on November 4th, the proposal passed. Sounds all fine and good, right? Well, maybe not. If the FCC’s current plan goes through, it will lead to a crossroads for the wireless microphone industry and for AV designers. (more)
Subscribe via email
Enter your email address
Delivered
by FeedBurner