Tag Archives: video conferencing

Connected Classroom: Integrating the Best Audio Solutions for Advanced Classroom Installations

Systems Contractor News Audio IssueAs published in Systems Contractor News and on AVnetwork.com, March 24, 2015

Imagine this all-too-familiar scenario: Your child comes home from school. You ask him “How was your day?” You get the usual answer: “Ok.” You ask him what he did, and get the usual answer: “Nothin. We learned stuff.” With that, he buries his head in his iPhone, and off he goes to his room.

Now, imagine the same opening question, but with this answer: “It was awesome. We had a conference call with The President of the United States, The Prime Minister of England, The Dalai Lama, The Pope, and another fifth grade class from Perth, Australia. And I got to ask the Pope a question.”

See the difference? In the second scenario, we have an engaged, interested student. That’s what the connected classroom will do for education. This is not a futuristic dream from a science fiction magazine; we have the technology to do this today. In ten years from now, almost every classroom in the U.S. will be connected.

There are many technological challenges in building the connected classroom. Things like bandwidth, internet connection, and hardware will offer integrators and manufacturers challenges never before faced. In my mind, the biggest challenge will be audio. We all know a videoconference is only as good as the ability to hear the people speaking.

There is no perfect solution, or one-size-fits-all. With every audio solution, there is an advantage and a drawback. Below are a few ideas I have for setting up microphones in the classroom. This is based on an interactive, two-way conversation, not a “sage-on-the-stage” lecture. I believe that a webcam with a pinhole mic on the top of a TV is not a good solution. It is good for the consumer setup. Remember that the goal of setting up a mic is to get it as close to the subject speaking as possible.

1. A single mic on a stand—In this set up, the person asking a question steps up to the mic. The advantage, only the person speaking will be heard. The mic can be turned on and off when needed. Disadvantage, there is a lot of getting up and down during the meeting. In some cases this disruption is manageable, but not likely with a classroom of fifth graders.

2. Ceiling mics—Mounting mics on the ceiling, in a permanent installation. The advantage, audio is unobtrusive and there is no need to set up and take down. You can pick up anybody in the room, and the wires are hidden. The disadvantage is that ceiling mics tend to be difficult to work with due to room acoustics. An expensive DSP is required to tune the sound properly, but it is probably too expensive for a school district on a budget when outfitting a large number of rooms. If it’s always on, it will pick up every sound in the room, which is distracting.

3. Stick mics for each desk—There are systems mics that daisy chain to a master system. Each mic has a mute switch, so it can be turned on only when needed. The install is most likely temporary. The advantage is that everyone can be close to the mic when they speak, without getting up from their seat. No extraneous noise, since the mic is off except when needed. The disadvantage is that temporary setup means wires all over. There is also time needed before and after the conference to setup and break down. These systems tend to be expensive, and difficult for the novice to set up and work.

4. Multiple boundary mics—Boundary mics can be set up in front of the class, with a master mute switch for the teacher to turn on and off as needed. The advantage includes very few wires, and all of them are in the front. The disadvantage, set up and breakdown take time, since it’s a bit difficult to set up, but not as difficult as the stick mic solution. Also, the people in the back of the room may not be heard well, depending on the size of the room.

I know there are variations of any of these. Wireless systems can be integrated into any of these, eliminating wires strewn all over the place. However, wireless systems can pick up noise, and are difficult to manage for the novice sound engineer.

The most important thing to consider here is that the schools have limited personnel resources. Most likely, there will not be technical support to set up these systems, which will leave it up to the already overtasked teacher. The solution must be easy to set up and use, offer quality sound and it must be inexpensive.


Web Conferencing 2.0: Better Picture, Better Audio

Old telephone set

Back in 1963, the Museum of Science & Industry in Chicago had a working picture phone.  It was two phones wired on a closed circuit together with TV cameras on both ends.  My cousin and I used to go to the museum and play with the picture phones, and dream about the day that we could do more than talk to each other, but also look at each other while we were talking.  It was so cool and so “Jetsons-esque.”

We got a big laugh when we talked about getting a “Picture Phone” call while we were in our underwear.  “How would we answer the phone?”  It was a big problem with picture phones that we weren’t sure how to solve.

Little did we know the real problems would be much more difficult to solve.

Fast forward to today. “Picture Phones” are everywhere.  I have been in electronics all my adult life, and have watched the progression from a series of low resolution still pictures with live audio, to full motion video.  What used to be futuristic is now everyday.

But video conferencing has a long way to go.  We are still in the early stages of development.  Limited bandwidth and low cost hardware delivers less than stellar picture quality.  And pinhole mics built in to the web cam, sitting on top of the monitor, 20 feet away from the furthest conference participant make that person difficult to hear.

I hate those web cams that sit on top of the monitor and look down on us.  It shows my bald spot.  I never knew my hair was getting that thin until I saw myself on the web cam in our conference room.  And on top of that, in order to get us all in, the lens is a fish eye.

But we accept this situation as the best that is available.  We are so happy to even be able to see each other, and not just hear, that a bad picture is acceptable.  And if the audio is a bit muddy, we learn to say “can you repeat that?” over and over again.

But it doesn’t have to be that way.  Right now, today, we have the technology to deliver a great picture and crystal clear sound.  And we don’t have to empty our bank accounts to do it.

I call it Component A/V.

At Marshall Electronics, we introduced a new, cutting edge way of delivering outstanding video and audio.  The concept is simple. Get the video and audio pick up devices down from the top of the monitor, separate them into their own chassis, and bring them closer to the participants.  And use high quality HD cameras for the video.

At Infocomm 2014, we showed a new kind of web conferencing system.  We used our new subcompact HD cameras, with interchangeable lenses for our web conferencing system.  These are the same broadcast quality cameras we sell into the TV production industry.  By running them through an HDSDI-to-USB 3 converter, it takes a broadcast quality picture and turns it into a beautiful web conferencing image.

Because the camera is so small and unobtrusive, it can be placed much closer to the conference participants, without being a distraction.  Bringing it down to eye level gave the conference a much more normal and intimate feel.  Also, by having a choice as to what lens to use, the picture is custom tailored to the specific need.  We all prefer to have conversations looking at each other directly in the eye, not looking down on each other.

Now that web conferencing is an everyday technology, it’s time to improve the picture and sound.  Companies are demanding better quality video and sound.  And, with the current technology, a quality HD web cam is well under $1,000.  It’s more than the $100 consumer web cam we are currently using but less than an airplane ticket and accommodations for a face-to-face meeting. As companies rely more and more on web conferencing to do business, they are willing to pay the additional cost of an HD web cam to make the picture look natural and thus the conversation becomes more natural.

And, since I don’t go to the office in my underwear, I don’t have to worry about taking calls in my boxer shorts!

There, I solved a few problems.  Better picture, and no underwear calls.  Next time we will talk about audio.

Connecting The World

by Perry Goldstein


As Internet communication continues to improve, it seems the world is getting smaller and smaller.  Just thirty years ago, sending a video meant putting a VHS tape in the mail. Audio messages were left on answering machines containing little cassettes. Twenty five years ago, text-only emails were the newfangled way to communicate.

Now we can transmit full motion video and audio messages in microseconds, in full high definition.  We can include multiple parties, and collaborate on shared documents, from anywhere in the world, in real time.  We can use the Internet to create our own TV channel and reach millions of people for the cost of a basic computer and broadband connection.  It’s amazing.

Marshall Electronics and MXL have been known for some time as an end-to-end hardware solutions provider for the broadcast and pro audio markets.  Over the past few years, we have found that our products are gravitating in ever increasing numbers to the IPTV and VoIP markets.

Both of these markets are growing at exponential rates.  As costs go down and quality goes up in hardware and “production” related services, more and more users are entering this world.  We are continuously evaluating and creating new solutions for these new media.  Some are good for collaborative web conferencing, some for one-way IPTV, and some have crossover capability.  It’s difficult to assign them to a specific category.

The ecosystem of these communication systems is very complex.  There are cameras, microphones, switchers, encoders, computers, software, hardware mounting, to name just a few.  We make many of them right here at Marshall.


Marshall Electronics recently introduced a series of mini and mid sized HD cameras, capable of multiple frame rates and resolutions.  This makes them good for broadcast, streaming and even VoIP.  Originally, VoIP (Voice over Internet Protocol) was a term for collaborative voice-only communications.  Today it is accepted to include video, and is commonly known as web conferencing or video conferencing.  There are many ways to use these cameras for VoIP.  MXL has introduced a USB3 converter, taking either an HDMI signal or HDSDI signal, and converting it into a USB3 signal.  Coming soon are conferencing system switchers that have multiple inputs for either HDMI or HDSDI cameras.


When MXL was founded, the primary microphone produced was the condenser mic, used for recording studios.  Over the past five years, we have become known for our web conferencing mics.  Our first VoIP mic, the AC-404, is one of the best selling and most highly regarded USB boundary mics in the market.  From that start, we have expanded the line to gooseneck mics, wireless mics, audio mixers, and various audio solutions for both the VoIP and IPTV markets.


Marshall has had a line of encoders and decoders for a number of years now.  As video distribution moves from satellite and cable to the Internet, Marshall offers a number of solutions to meet this growing demand.

Video Switchers

The end user is becoming more and more sophisticated.  They are discovering that a one-camera production, be it for IPTV or VoIP, is no longer adequate.  Multiple cameras with interchangeable lenses will give the operator the choice of camera placement and focal lengths.  This can be accomplished with an HDSDI camera with the capability of running up to 300 feet of cable, which makes this a great solution for conference rooms or TV studios.  MXL will be releasing a simple-to-use, four-camera, seamless switcher in the spring of 2015.   With an IR remote, the switcher can be operated remotely, which makes this a one person solution.  It is also designed to be portable and battery powered.

Audio Mixers

The biggest issue in the world of electronic video and audio is the lip-syncing.   Video often has latency, caused by all of the electronics it passes through.  That can cause the sound and movement of the speaker’s lips not to match.  We have all seen that on TV somewhere.  It can be very annoying.  MXL will be releasing an audio mixer capable of taking multiple mics, mixing them and adding delay to accommodate for the video latency.  This mixer will also be capable of running on a battery.

It’s an exciting time to be in electronics.  There is a revolution of services and products making it possible for high speed, low cost communications.  Now, anyone of us can have our own IPTV channel, You Tube Channel, or professional collaboration web conference.  With the growth of these services, better hardware is needed to deliver the best picture and sound possible.  Marshall and MXL are dedicated to bringing unique solutions to market to enhance the user experience.

Keep an eye out for our blog posts and email updates as we announce these new products.  We are excited to help bring the future to you, today.