Setting up a wireless microphone system can get complex if you want to do it correctly. With the recent FCC auction of the 600 MHz (Megahertz) band of frequencies, users of wireless microphones all across the country are being forced to reconfigure their wireless systems. The age of having the freedom to leave huge gaps between your wireless microphone frequencies is over as the amount of available frequencies has been drastically reduced. Because of this, it is important to purchase the right equipment and make the right choices when setting up your new system.
How to Set Up a Wireless Microphone System
How do Wireless Microphones Work?
Unlike all of the other popular microphones in the world, wireless microphones send radio waves just like your FM radio to send audio signal wirelessly from a microphone to a wireless receiver. Almost all wireless communications, including LAN, Bluetooth, cellphones and television broadcasts use radio waves. Radio waves are measured in frequency with the lowest frequency waves having the ability to travel the furthest and the highest frequency waves the shortest.
Wireless microphones operate in the UHF, or “Ultra High Frequency” range between about 300 and 1000 MHz. This range of frequencies is governed by the FCC, the Federal Communications Commission, where they designate sub-ranges of the UHF range for various functions. For example, the 225-420 MHz is reserved for government use, while the 849-851 MHz bands are reserved for commercial aviation systems.
The FCC designates the certain MHz bands for unlicensed use of wireless microphones. That being said, these bands of frequencies are not reserved or kept open for the use of wireless microphones. This space for unlicensed activity is often a free-for-all of signal. As such, when you’re setting up your wireless microphones, it is not uncommon to find interference across several of your wireless channels. There are however steps you can take to make sure your system can differentiate interference from your desired signal. This guide should help you to make sure that happens.
Choosing the Right Wireless Microphone
There are a lot of affordable options out there for wireless handheld or headset microphones and receivers. You’re obviously going to want to make sure that you’re buying a quality microphone, but for the purposes of this guide you’re going to want to examine the receiver first. The ideal receiver touts the more advanced “True Diversity” technology as well as outputs for coaxial cables that allow you to connect your receivers to an external attend (we’ll get to that later).
True Diversity receivers have two separate antennas running on two independent receiver sections. The antennas on opposite ends of the receiver and the receiver constantly compares the signal between the two antennas and captures whichever signal is the strongest. This provides a much more stable connection as the odds of having both antennas drop signal simultaneously is very low. You’ll also want to make sure that you’re purchasing a system where the settings can be adjusted easily on both the handheld microphone or body pack as well as the receiver rather than only on the receiver.
Wireless microphone systems come in a variety of mic and receiver types.
Both Shure and Sennheiser offer some of the highest technology in terms of microphone quality and receiver reliability. Although we did provide many great options in our 10 best wireless microphones guide that’s gained a lot of traffic through out the years, I lean more towards the Sennheiser models as I find them easier to set up.
This Sennheiser EW 100-953 G3 system comes with a very high quality dynamic microphone and a receiver that checks all the boxes in terms of features, ease of use, and reception strength. Here is the handsfree version of the same system.
Choosing the Right Wireless Frequency
Here is where setting up a wireless microphone system start to get tricky, and some mistakes may occur. Some receivers have a built-in scanner that will automatically scan through the frequencies and give you the ones that have the least interference. This is similar to the way your old television tuner used to be able to scan for available channels on setup. The Sennheiser system above, and many like it, offer instant data on noise coming across that frequency as you scan across your channels. The two bars on the left of the receivers display offer you information signal strength and volume.
As you scroll through each frequency, stop for a moment and observe those two bars. The channels with the least amount of activity are the channels that will be the best for setting your microphone. Once you have your channel set on the receiver, you can quickly sync the receiver with your microphone by using the quick sync function that comes with the Sennheiser model. If your model does not have a quick sync function, you’ll simply tune your microphone to the same frequency as your receiver.
Finding the right frequency can be tricky, but effective when taken the time to do so (Source; YouTube.com).
Now just because you have a signal does not mean you’re done. Make sure you’re scanning and setting your frequencies in the same space where you’ll be using the microphone. Just because your wireless mic connected flawlessly in your living room does not mean it will work as well when you take your system with you to the location of your gig. Ideally, this process of scanning and selecting frequencies should take place at every new location.
Now many microphones and receivers come with the ability to quickly change between preset channels similar to the way you can save 6 radio stations on your car radio. If you’re constantly using your wireless system in the same spaces, you can find frequencies that work, save them as presets, and switch quickly and easily after the first scan at each location.
Strengthening Your Wireless Microphone Signal
Remember when we talked about those external antennas? For anything larger than a 50 foot gap between the microphone and the receiver, an “elephant ear” style external antenna is going to be an absolute must-have. You can use any brand of antenna with any brand of microphone, as long as the frequency range on the antenna is the same as the frequency range of your microphones. The good news is, you can use up to twelve microphones with one pair of antenna!
If you’re following this guide and using a true diversity receiver, you’re going to need two antennas in order to continue to reap the benefits of true diversity technology. To keep things consistent, I’ll recommend a pair of these Sennheiser A2003-UHG Directional Antennas (these are ordered one at a time so make sure to have two in your cart at check out).
These antennas conveniently screw into the top of a microphone stand like a microphone clip. You want to have the face of the antenna aimed at the general direction where your microphones will be. You can plug a pair of these antennas directly into your microphone receiver using these coaxial cables. If you’re going to connect multiple receivers to your antennas, things start to get a little confusing.
There are two ways to plug multiple receivers into one antenna. You can either use passive splitters or active splitters. Passive splitters are exactly what they sound like, splitters that passively split the signal without any amplification. When using passive splitters, you’ll actually lose about 6 decibels of signal for each splitter. If you’re only splitting it once or maybe even twice, you can get by with this method. It is far less expensive than using active splitters.
Active splinters allow you to split the signal without any loss of sound. This Sennheiser ASA1 Splitter will work perfectly with the equipment listed above. It even comes with 8 coax cables! This unit will also power your receivers so you’ll no longer need to use AC adapters to power each individual receiver, freeing up lots of space on your power conditioner or power strip.
Each splitter comes with two antenna slots (one for each antenna in the true diversity system) and 8 slots for receivers. You’ll be connecting two cables to each receiver, one for each antenna signal, so this allows you to connect 4 receivers to two antenna. Now I know what you’re thinking… Yes I did mention earlier that you can connect up to twelve receivers to one pair of microphones. This will be costly, but can be achieved by connecting four splitters to one main splitter instead of 4 receivers to one main splitter. Each splitter can then be connected to four receivers, allowing you to connect up to 16 receivers to one pair of antennas. This is about as many receivers as you’ll want to try to connect to one pair of antennas.
Setting up a wireless microphone system can be costly and confusing but like most other audio endeavors, it is worth it to spend more money and do it right the first time rather than try to repair something that was done haphazardly down the road.