Tag Archives: USB microphone

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.


Can You Hear Me Now?


The progression of the Audio/Video industry is fascinating.  The first broadcast medium was audio only…it’s called radio and it was used primarily in the home.  The first visual medium was film, and it was video only.

When they merged video with audio in film it was big.  When they merged video with audio in broadcast, they called it TV, and it changed the world.

In the electronics industry, we spend a lot of time talking about video.  First it was video itself.  Then it was color.  Then it was the VCR.  Then it was SVHS.  Along came High Definition, and it changed the way we treat video.  4K, 8K, 16K, and all those Ks will keep improving the picture.  Who knows what else it will do?  Only time will tell.  (Here’s a cool infographic on the history of television.)

Video is fun.  Video gets attention.

No one really talks much about audio.  The technology is old, it hasn’t changed much over the years, and it just isn’t as sexy.

But without good audio, life is a silent movie.


People will accept compromised video – grainy, shaky, or low resolution.  But if they can’t understand what is being said, they will turn it off. 

Whether it’s web conferencing or shooting video, proper mic’ing of the subject makes all the difference in getting the message across.

Rule number 1 in audio is to get the mic as close to the speaker as you can.

Rule number 2 is to keep the mic out of the picture as much as possible.

Rule number 1 and rule number 2 are in direct conflict with each other.  What’s a poor audio engineer to do?

That is where the compromise comes in.  Use a microphone that picks up the audio, while keeping it out of the picture or in an inconspicuous place.  How does one achieve this objective?  Pick the best microphone for the situation.

 Audio In Web Conferencing

The standard practice in web conferencing seems to be a low resolution web cam with a built-in pinhole mic sitting on top of a monitor hung on the wall.  Basically, that means the closest speaker is about 6 feet away from the mic and the farthest is 15 to 20 ft. away.  With a low quality mic that far away from the subject, the sound will not be very good.  Add to that room acoustics, people talking over each other, and paper shuffling during the meeting, and the result is a web conference that is seen and not heard.

MXL offers various audio solutions that are affordable and bring the sound closer to the subject.

A USB Boundary Microphone is the easiest way to get good sound, without a big mic sticking up in the picture.  It will pick up an area of about 25 feet, 180 degrees.  In most small conference rooms, that is all that is needed.  Place it on the conference table, and the sounds “bounce” off the table and gets gathered up in the mic. There’s no obvious microphone in the camera view so you’re achieving the seemingly conflicting goals of close mic’ing and discreet mic’ing.

USB Gooseneck Microphones are a bit more intrusive but can be placed closer to the person speaking.  This is a good solution for a small meeting of four or five people.  The MXL AC-400 gooseneck can be used with up to four AC-40EXT extension mics.  They look very professional and do not call attention to themselves, and they deliver the sound quality you need.

These microphones will meet the web conferencing needs of most small to medium sized businesses.

Once you get past these options, things get a bit more complicated.  In some cases, there is no way around a more complex and expensive solution, especially when the room is larger and there are many more people in the meeting.  In that case, a combination of table mics, ceiling mics, and a DSP is probably needed.

Our goal at MXL is to provide low cost, simple, high quality solutions for web conferencing.  One thing that has made this possible is the introduction of software programs such as Microsoft Lync, Bluejeans Network, and Vidyo, to name a few.  All of these programs have echo canceling built into their systems, eliminating the need for an expensive echo canceling solution built into the mic.

What makes web conferencing so popular is the low cost and simplicity that the digital age has created.  It can be done with nothing more than a computer, TV, camera, microphone, and broadband connection. Check out my post on video for web conferencing.

Because of the affordability, small companies are now adding web conferencing systems to their offices.  Large companies are expanding them out to all of the conference rooms and offices, instead of just one main room.

In short, if you are in the process of adding web conferencing to your office, remember that your conference is only as good as the sound.  Make sure to move that microphone off of the top of the monitor and down closer to the people.

Look for two new boundary web conferencing microphones coming very soon from MXL!