Category Microphones

Tim’s Tech Talks – March 2020

By in Microphones, Sound System Upgrades, System Maintenance Tag , , ,

“Because Physics.” That’s a phrase that I find myself using when I explain “the why” about sound systems. Often I hear questions like; “Why can’t we put the speakers here?” or “Why can’t we use this kind of microphone?” As a system designer, I’m keenly aware of how sound waves interact with the structure of your room or how microphones work. Physics is why your sound system can have feedback or your hearing assistance system can’t transmit properly when you push the expandable antenna all the way down. Physics is the reason that you can hear low frequencies but not high frequencies when you stand behind a speaker. Physics affects if I recommend acoustic treatment in some rooms and not in others. Physics is critical in everything from the gauge of speaker wire to the location of wireless mic antennas. I’m not just expressing my opinion, that’s how God made the world. It has rules and we have to live by them. Sound has predictable characteristics if we take the time to understand them. So take a minute, be curious and revisit your high school physics class. You might be surprised at how it can help you understand your sound system.

Tim’s Tech Talks – November 2019

By in Microphones

It’s that time of year again, Christmas Concerts, Cantatas and Children’s Choirs.
As you get ready for Christmas groups, it’s a good time to review the 3:1 rule of choir micing. It’s really pretty simple, if your mics are 1 foot from the choir, they should be at least 3 feet away from each other. But why is this important? Don’t we want more mics? More is better, right? Actually, when it comes to choir mics, less is more. There are a couple of reasons.


1. Feedback. In live sound, the more mics you have “open” or on, the greater your chance for feedback. Because micing a large group requires that the gain be turned up, you’ve already increased the potential for feedback, so by adding more mics you’ve created even more potential.


2. Double Micing. So what’s the trouble with this? When two microphones pick up the exact same source and are sent to your mixer, something happens. They cancel each other at certain frequencies. You may have heard this before when Pastor comes up to the pulpit and his wireless mic and the Pulpit mic are on at the same time. You get this weird “hollow” sound. It also changes as he moves around, in and out of the pulpit mic’s pickup zone. One of the biggest problems of over micing a choir is that it tends to sound worse, not better. Repeat it with me, “Less is more, less is more!”

My choir at Front Range is about 40 people, four rows deep and I use two (yes two) microphones. It’s all about placement. For choirs with multiple rows, put the mics higher than the front row. Mics up high, minimizes the distance difference between the rows. Next, point them down into the middle of the choir. Most directional choir mics have about a 120 degree angle of acceptance and this coverage increases as you get higher. For smaller choirs you can go lower. Remember, avoid placing your mics directly in front of the front row or the result will be a couple of solos instead of a choir.


Merry Christmas!