Showing posts with label av. Show all posts
Showing posts with label av. Show all posts

Tuesday, July 9, 2013

Audio Networking: AV Meets IT

     The world of analog audio has been on its way out for some time, and digital audio has been moving in.  Now there is a new culprit entering the scene, and that's networking.  The integration of digital audio means audio networks can now gain massive territory.  To illustrate, I will paint scenario.  
     The old way of designing an audio system was through analog means.  There would be a mixing board with physical inputs, analog cabling routing to processors, and then an output to speakers.  This is one of the simplest forms of an audio system.  In the analog domain an audio network gets messy as it grows in size.  This is due to the cabling, power, and space requirements. 
        Today’s technology has taken the world of network routing, and applied it to audio system applications.  Think of how your Internet and corresponding devices are set up.  You have your router that grabs the Internet from your provider to supply to your household.  Then every device you want on the network connects to that router somehow; whether it is physically or wirelessly.  All of those connected devices can now talk to each other and the Internet.  So, now you can print wirelessly, connect to the Internet, and share files remotely with other computers in your household.  These are the basics of networking and now you can do it with audio systems.  
     Audio is starting to use the same blue Ethernet cable that is used for Internet networks.  Ethernet has the capability to carry more audio signals than an analog cable that can only carry one.  So already there is an advantage.  Manufacturers are also developing digital audio devices that have the capability to talk to one another intelligently.  Addresses are assigned to each device that is attached to the network and with little manipulation from the user; these devices can talk to each other.  This is called Audio over Ethernet (AoE).  More commonly you will see it described as a Cobranet or Dante system.  These are two common systems that allow audio over Ethernet at great speeds.  Another advantage of having audio devices on a network is the ability to control and monitor them remotely.  There are some brands that allow the end user to monitor and control a device from anywhere in the world through the Internet.  The manufacturer sets up a web portal that allows the user to log in to his/her device(s) and control or monitor.  This is huge because I have witnessed first-hand, times when the crew needed access to a piece of gear but didn’t have the authorization, and the only guy that did was not there.  Having network capabilities eliminates that problem from occurring, or at least greatly reduces it. 

     So hopefully you can start to see how much of an advantage it is to have audio systems set up in a network configuration.  It allows for more complex systems, reduction in cabling, and expansion of use.  However, these systems are far more complex to design and install.  This sums up my introduction to the world of networked audio.  There will be future posts delving deeper into the equipment and techniques used to design and operate these systems.  

-Jon

Friday, February 15, 2013

The Subjectivity of Noise

     There is noise all around us.  City streets filled with roaring buses and people on their cell phones.  There is so much noise around us that we tend to ignore it.  Ignoring the noise does not make it go away. Noise pollution is often the last thing to be considered when designing a building.  Noise is considered to be any unwanted sound.  This definition is a bit subjective since everyone has different ideas of what can be categorized as unwanted sound.  Someone may say the sound of their neighbor banging away on drums at midnight is noise, while the drummer perceives it as music.  While the threshold of what delegates wanted from unwanted sound is blurry, there are many things that are considered noise in which society is in agreement.  Below is an amusing picture that helps to illustrate the subjectivity of noise.


The sign above states that "unnecessary noise is prohibited," but what constitutes unnecessary noise? This sign does not make sense because what is considered noise to someone may be pleasing to another.  And is there such a thing as necessary noise?  If noise is defined as unwanted sound then necessary noise would imply that it is in fact wanted, therefore contradicting the definition.  So all this sign does is produce a paradox.


     Noise pollution is a growing concern in the world today and before we can tackle this issue, we need to first define the types of noise that are polluting the environment. To do this we must look at the noise sources that society is in agreement. Such sources can include traffic, trains, rooftop HVAC units, and loud machinery. Noise sources are location based so in a school, noise can be the classroom next door being too loud. This is a noise source for students in the other class. They will have trouble paying attention and studying when noise from the class next door is being transmitted into their learning environment.

   The following LINK will show an article about rising noise levels in New York City.  The noise level are getting so bad that hearing loss is being caused over extended periods of time.  Exposure to high decibel levels for extended periods will cause hearing damage, and when the people of New York are experiencing 70dB and up for more than 8 hours a day it begins to take its toll. 

     Future blog posts will dive deeper into these various sources of noise as well as common methods of treatment.  For now, understand that the best way to treat noise is at the source.  Engineering said device to not emit strong noise levels is the best solution.  However, most of the time it's very expensive and time consuming to go this route.  Click HERE to see some information on types of noise and some common ways to treat them.  This will help to further explain what I have just talked about and also serve as a transition into future topics. 

-Jon Owens
Audio Engineer/Sound Designer/Acoustic-AV Consultant
www.jon-owens.com