Introduction: Problems With Wireless Microphones and How to Fix Them

Picture of Problems With Wireless Microphones and How to Fix Them

Because there are so many problems that you can have with a wireless microphone system, I have decided to write an instructable on how to troubleshoot wireless systems.  This can apply to other wireless systems besides microphones, but I will be focusing on microphones, since that is what most of my experience is in.

If I miss anything, or you would like me to add something to this instructable, please let me know.  Also, if you are having problems that are not wireless related, please see my instructable "Audio Problems", or feel free to contact me for help.

Please keep in mind that I can only cover a few problems you can run into with wireless.  I will only cover the basics in this instructable.

Step 1: Static

Picture of Static

This step is taken from my previous instructable "Audio Problems".

Static on a wireless mic is usually caused when the mic is too far away from the receiver, a battery is dieing, or when something is interfering with the signal.  We will cover interference in another step.  Often the simplest way to resolve static is to change the battery, or to get the mic closer to the receiver.

A good way to get the mic closer to the receiver is to move the receivers to an area backstage or onstage.  Many facilities already have wire run from their backstage or onstage areas to their tech booth.  This is generally considered the "correct" way to use a wireless microphone system.

Step 2: Interference

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To fix interference on a mic, you need to adjust the frequency on the mic and receiver to another frequency that is not in use.  (Unless you are a licensed operator that is not restricted by Part 15 of the FCC rules and regulations.)  Consult your owners manual for information on how to change the frequency.  You want to change it at least 2 MHz up or down from where you were having interference.  Mostly, you just have to play with it in order to find what the best frequencies are in your area.  You can also use a wireless frequency analysis program, but those are expensive, and require expensive hardware.

Digital microphones use about a tenth of the bandwidth that an analog mic does, but with some of the cheaper digital mics, you can run into problems with a high latency.  (High latency is when there is a noticeable delay between when the person speaks and when the sound system produces the audio... latency is the time it takes for the signal to travel from the source to the destination.)  The reason digital mics have a high latency is that audio is basically analog.  Digital mics have to convert an analog signal into digital, then convert that digital signal into analog.  Not to mention that they will select the channel with the least attenuation.  Granted, this processing takes milliseconds, but add enough milliseconds together, and you will have a noticeable delay.  Most of the major manufactures have fixed this problem in recent years.

Step 3: Channels "Mysteriously" Changing

Picture of Channels "Mysteriously" Changing

Sometimes when you have a microphone that is synced to the receiver via infrared, the microphone will "Magically" change to a different channel, or change a setting.  This doesn't happen often, but it does happen enough to mention.  This is an easy fix, first, find the infrared receiver on the mic (I have mine pictured in this step), then place a small piece of gaff tape over the receiver.  If you need to sync, simply take the gaff tape off and replace when done.

Step 4: Power Off

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I can't tell you how often I have had actors/musicians/etc. turn off their power switch for whatever reason, and then forget to turn it back on.  Even when you tell them not to!  Here are two ways to fix this problem:

1.  Most microphones have a power lock.  This will keep the mic on, even if it is switched off.  This is the most effective way.  The only way to turn it off is to know how to remove the power lock, or to remove the battery once you turn the power lock on.  Refer to your owner's manual to see if your mic has power lock, and how to turn it on.  Since Shure ULX is one of the most popular mics, I will tell you the process for that one.  Press set, then mode together (set has to be pressed first) until you see Po L on the screen.  It is now power locked.  Generally most mics (including Shure ULX) use the same key-combination in order to unlock that they did to lock.

2.  Place a piece of gaff tape or medical tape over the power switch.  Most people will not remove tape for fear of breaking the mic, and it also protects from accidentally bumping the switch off.

Step 5: Intermodulation

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Intermodulation is similar to interference.  Intermodulation happens when you have two microphones or other wireless devices crowding each others frequencies.  The only way to fix this is to change your frequencies to another frequency that is not crowded.  To find frequencies that are not crowded, use an intermodulation analysis program.  One of the best programs available is IAS, however IAS is very expensive.  A free program from Sennheiser is available called "Sennheiser Intermodulation and Frequency Management Software" (AKA SIFM).  It is a very good option if you use Sennheiser microphones, as it already has some of their major models specifications programmed into the software.  You can add other specs in, but you need to know the specs.  I mostly use IAS, so I don't use Sennheiser's software that often, but to the best of my knowledge, you can only use one model at a time with SIFM.

Also, frequency crowding is caused when you are using too many mics at the same time.  Generally, you can only use about 16 analog mics at the same time before you start to have frequency crowding issues, however, if you use a program like IAS, and depending on the area you are located, you should be able to get as many as 22 analog mics.  If you need more than 16 mics, than you should go with a digital system.  As I mentioned before, digital mics only use about a tenth of the bandwidth of analog mics, so you should be able to use about ten times the number mics you could use if you are using analog.

Step 6: Antenna Problems

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The antennas of a wireless system are the most important part.  If you have a damaged antenna, or the placement of the antennas on your receivers are off, then you are going to have some big problems.  Most wireless body-pack transmitters have a little wire coming out of either the top or the bottom of the pack.  Make sure that this is not being stressed in any way, as that can severely damage the wireless signal.  Also, the antennas on the receiver should be tilted at an 90 degree angle if you are using the antennas that are included with your receivers.  You can also get directional and omi-directional external antennas that will significantly improve your wireless range.  If you are using directional antennas, make sure that you have them at least 5 ft apart and that they are aimed so that they cover the whole area you want to cover.  The best case in scenario would be to have them 10 ft. apart, but that can't always happen.

Any fixed frequency microphone will have an antenna that has a specific length.  You can not change the length, or it will not work well.  If your antenna on a fixed frequency mic goes bad, then you have to get the exact same antenna from the manufacture if you are going to fix it yourself.  Otherwise, get a new mic, or send the mic in for service.

Step 7: Signal Blockage

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One of the most common problems with wireless systems is signal blockage.  Walls, metal, even the human body can affect signals.  There isn't too much you can do about signal blockage, except trying to move your receivers around trying to find a good spot that is not blocked.  Also, make sure that antennas are not touching a person's skin.  The human body acts as an antenna, absorbing signal.

Step 8: Wireless Microphone Brands

Picture of Wireless Microphone Brands

One of the most effective ways to get good wireless quality is to get the proper wireless system for your needs.  If you are going to install your system permanently, hire an AV consulting company to come in and do a wireless analysis.  This is the best way to determine what microphones will meet your needs, and in the long run it will save you money.  If you are using a portable setup, make sure to over-compensate for problems you may run into.

I have listed my opinion of various wireless companies below.

Shure:
Pros:
Name brand company, almost everyone has heard of Shure.  Their cheaper products are good for some applications.  They have somewhat decent sound quality.  Easy to use interface.  Very good digital products.
Cons:
Products made very cheaply, do not hold up well to professional use.  Their analog systems are prone to wireless interference more so than some other brands.  Will not hold up for a portable system.
Bottom line:
If you are on a budget and don't need a lot of mics, get one of their cheaper products.  Also, their digital products are very good, so if you are going digital, Shure mics might be a good way to go.  Don't buy for portable systems.

AKG:
Pros:
Good sound quality.  Name brand.  Reasonable price.  Very powerful.  Easy to use.  Holds up to wear and tear.  Good for portable systems.  Not bad for installed systems.
Cons:
Most of their products will overpower other brands.  Don't buy if you are mixing cheaper brands.
Bottom line:
The best option in my mind.  Just don't use if you are using a Shure or cheaper mic at the same time.

Sennheiser:
Pros:
Fantastic sound quality.  Name Brand.  Best wireless quality between AKG and Shure.  Easy to use.  Holds up to wear and tear.  Great for all systems.
Cons:
Pricey.
Bottom line:
If you have the money get Sennheisers.

Lectrosonic (thanks to jakdedert for reminding me about this one):
Pros:
Fantastic sound quality.  Name Brand.  Considered to have the best quality of any company.  Easy to use.  Holds up to wear and tear.  Great for any system.
Cons:
Pricey.  Probably the most expensive mic out there.
Bottom line:
These mics are mostly used in video production and for productions with an unlimited budget.  If you can afford a Lectrosonic, then there is no doubt that it is the right mic for you.

Audio Technica:
Pros:
Good mic.  Nice user interface.  Better wireless quality than Shure.  Holds up to professional use.  Decent price.
Cons:
Not as good sound quality as Shure.
Bottom line:
Not a bad mic for those who are on a budget.

Line 6:
Pros:
Decent digital systems for the money.
Cons:
Not as good as Shure for the digital.
Bottom line:
Good entry level digital system.

Nady:
Pros:
None.
Cons:
Terrible wireless mics.
Bottom line:
Don't buy nadys wireless products.

VocoPro:
Pros:
You get lots of mics
Cons:
Very prone to frequency crowding, and there's nothing you can do about it since they are fixed frequency.  Terrible sound quality.
Bottom line:
OK if you don't expect to use all the mics at once and are on an extreme budget.

There are other brands out there, but these are the ones you will see most often.  If you have a question about a specific brand, please feel free to ask me.

Step 9: Copyright

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Please note that I do claim copyright to the information. I did not use any specific sources when compiling this information, all of this is from my personal experience.

You may quote parts of this information for educational purposes. Under no circumstances will you sell this information.

I do not own the copyright to the of the images in the introduction steps 1-2, and 4-8, however, as far as I have been able to find, I have the right to use it in this instructable. If there is any question about whether or not I have the right to use this image, please contact me. I have no intention of stealing anyone's intellectual property.  I do claim copyright to the image on step 3.

For further information on copyright, please see the license agreement to the right.

Use of this information implies that you agree to these copyright terms.

© 2012

Comments

jze (author)2014-03-26

Hi there, i've been given a field recording which seem to have audio glitches on it. the glitches are not a click but a short burst of noise, like someone rub or brushes against the mic. According to the recordist, nothing of that sort happen. Do you have an idea where it comes from? Could it be that the frequencies on the wireless system are relatively close to another?

JohnP427 (author)jze2016-05-29

I have the exact same issue with my GLXD BETA87A. When I yell it makes a short load burst of white noise. Does anyone know what this is?

Carmie05 (author)JohnP4272017-08-02

That definitely sounds like interference. You probably want to scan for a cleaner channel and/or raise your squelch level on the receiver. Squelch is a function that blocks out any RF that falls below a certain level. If you want a little more info I have an article on my blog you will want to check out. Also email me if you have any questions. Carmie05@aol.com https://avninjablog.wordpress.com/2017/08/01/8-useful-tips-for-handling-wireless-mics/

FireAce4 (author)JohnP4272016-06-02

Shure just released a firmware update for the GLXD system. I gave them a hand in testing it before it was released a couple weeks ago. It should fix this issue.

JosephC273 (author)2017-07-18

I have Sennheiser Radio mic belt pack EW100.

Every now and again (about 10min) I get a spike.

What causes it and how can I stop it from happening?

Kind Regards

Joe

rokknrob (author)2017-02-16

Hi, I had two wireless AKG mics that were 15 years old so I bought two Samson concert 88 dynamic wireless mics. for a karaoke system set up permanently in a bar setting. Two fifteen in JBL and two 10 inch JBL speakers. System sounds great and the mics blow away the AKG's. The small problem I have is that now with the two new mics I have a (for lack of a better word) SNAP sound when certain people use one of the mics. It is intermitten. Maybe two or three snaps during a song and only on certain singers it seems.They are 16 channel true diversity mics. I haven't tried changing the freq. yet. the Freqs. are 0 thru 8 and A thru H. I have one mic on 0 and the other on F. Is there a reason I would get a snap on a new mic? I guess you could call it a (crack) too. Any information would be appreciated.

rohit_puri50 (author)2016-12-06

Hi, I bought "Soulo Digital Wireless Mic", it comes with a 30 pin connector, which connects the mic with the device for the sound output. But i am unable to connect the wireless mic with the connector (which i have connected with the phone or iPad). can anyone help

DavidP151 (author)2015-10-13

i have a problem we have a lower end set of wireless microphones and one day the reciever just stopped picking up the mics

sally.smiththurman (author)2014-08-04

Hi, I work for a low budget church and suddenly find myself responsible for a sound system I do not completely understand yet. One of our handheld wireless mics suddenly sounds "tinny", like there is no bass in people's voices. I don't know if this is a setting on the transmitter (nobody has touched it or changed it) Or if something has "blown out" in the mic and we just need to replace it. Looking it up I see that will cost us $250 to replace it and we have to be careful with money but I would also like to figure it out myself, because if we call in the sound technicians it will cost us more.

gluvit (author)2013-12-03

Helpfull

Rgamer1 (author)2013-11-25

Hi
I have an issue with the microphone set that is pictured above. The other day I was running the sound board for church. While I was running this only the clip on mics were being used. I look down to see if the next speaker has a turned their mic on for the next part. I then realize that the hand-held mic has a one dot on the signal bar. I thought "Strange what is causing this" because normally it would show all dots for the best strength. I go get the hand-held mic which was put away and I notice that it was off. This was really weird. We turned the receiver for that mic off and then back on and it seems to be fine. You seem to be the only person who would know this so far in all my searching for the issue. Do you think this might be interference with the other mics or is it showing its weaknesses since we have had it for ten years?

tekdva (author)2013-10-11

Good information.
We have the same AKG handheld as pictured above and the battery won't stay in place. Even with the battery cover on, the battery keeps popping out, which turns the mic off. Any suggestions?
Thanks!

rosiehall (author)2013-06-21

have you worked with capture before? its giving me major difficulty

thegeeke (author)rosiehall2013-06-21

I have not worked with them before; but what are they doing?

rosiehall (author)2013-06-12

i am using Shure wireless microphones and 1/4 isnt even getting any signal. do you have any possible ideas for me to try and get it to work?

thegeeke (author)rosiehall2013-06-13

Does the XLR connection work? Sometimes there is a switch on the back to switch between the XLR output and the 1/4in connection (this helps reduce noise on parallel outputs). What model Shure is it? If I know the model I can probably figure it out easier. It is possible that the wiring inside the receiver is damaged or loose. Shure is decent about covering their products... if it isn't a simple matter of a switch, you might want to give them a call to see if they will cover the repair. If the XLR connection works, they will not repair it for free, and you need a 1/4 in connection; then you could get an XLR to 1/4 in adapter. Unfortunately just from what you are telling me, I'm guessing that it is a wiring issue inside of the receiver. If you are comfortable with soldering, you could open the receiver up (careful... this will void your warranty!), and re-solder the connection on the 1/4 in plug, but other than that (or sending it to Shure or an authorized repair center), I don't know of a fix other than checking for a switch on the back, and possibly checking in the menus incase there is an option to switch between XLR and 1/4 in... but I've only seen it in the menus a few times.

Good luck! :)

thegeeke (author)Ranie-K2012-01-27

In response to your links:
First link: Got the picture somewhere else, since I can't read the language this is written in, I removed the picture just to be safe and will put another one in it's place shortly. Thank you for bringing this to my attention.
Second link: Stock photo, that site probably got it from the same place I did.
Third link: Didn't get it from that site, again I got mine from a stock photo site, and it's a picture of static. You really can't pin it down to a specific site.
Fourth link: Again, a stock photo. They probably got it from the same place I did.

I saw copyrights on the websites you listed, but not on the pictures. More than likely, they get them from the same stock photo sites that I use.

I specifically state that I do not claim copyright to the images, however, as far as I know I have the right to use them. If there is any question about that right, I remove the images right away.

Also, for some reason your comment did not show up in my comments section... I seem to remember that happening before on one of my ibles as well. Do you have any idea why that is, or should I report that as a bug?

Thanks again for bringing these to my attention... I do take copyright very seriously. Unless I believe I have the right to use an image or anything, I will not use it.

-thegeeke

FlatLinerMEDIC (author)thegeeke2012-02-02

This guy did this to me too, there was no copyright on the website ....and no comment appeared on my profile.

thegeeke (author)FlatLinerMEDIC2012-02-06

Ya... and it's weird... your comment just showed up on my profile, along with his. Just today! I wonder if there is something going on with the instructables website, or if there is some way he is hiding the comments. Also, he never responds to your reply! (At least he never has with this instructable, or my other instructable he posted something similar about!)

Now I will give him this:
I can't say one way or another if the first link he put on there has copyright on it, so I'm glad he let me know about that, but other than that he seems to be WAY too obsessed with the pictures. If you look at his profile, all his comments are about pictures!

Thanks for telling me, I was wondering if it was just me. :)

adam 101 (author)thegeeke2012-03-12

I'm afraid that that people like this will just get worse now that Google lets you drag images into its search bar.

thegeeke (author)adam 1012012-03-13

Probably. The problem is that many sites will use stock photos, (and probably get them from the same place that I do), and put copyright on the page. They're not copyrighting the photos, but rather the page itself.

jakdedert (author)2012-02-28

Most of the information is good, but you shortchange Shure pretty badly, and don't even mention the # 1 brand of RF mics used in most motion picture and video productions; Lectrosonics. The more expensive (and I do mean expensive...a couple of thousand bucks for a complete setup with one lavaliere transmitter/mic and one handheld unit), Shure systems equal any Sennheiser system. They are mainstays of the wireless world for presentations and other live productions. The Lectrosonic units are even pricier, but are nearly bulletproof.

thegeeke (author)jakdedert2012-02-28

You are correct, I did forget to include Lectrosonic. I don't use their products that much because they are so expensive (of course, that shouldn't be be an excuse... Some of those cheaper brands I've only used once...) I will be adding it in the next time I'm on a real computer.

I have to disagree with you about Shure. I've used most of their products, but I use the ULX series quite a bit. I've had nothing but problems with all of their analog products, especially with the ULX. I've spent hours on the phone with Shure to be sure it wasn't anything was doing wrong, of course none of their reps know anything, so they never resolved anything. Now I will admit that their digital products are good (I did mention that), but the reason Shure became popular is that at one time they were cheaper specs to specs than Sennheiser and AKG. I personally own the AKG WMS450 systems, and when I use it in conjunction with the newest ULX systems, it always performs better, and sometimes overpowers the Shures even though I've run intermodulation calculations. (And the WMS450 is significantly cheaper than the Shures!

I realize there are people who will stand by their Shure mics until the end, but I'm sorry. My personal experience with them has shown them to be unreliable.

Thank you for your input, and reminding me about Lectrosonic. I am currently working on another instructable about purchasing audio equipment. I plan to publish it in a week to a month. I am reviewing as many companies as I can remember at the end, but I'm not limiting myself to just mics... Would you mind if I sent you a link once I have it published so you can look it over and tell me if I forgot any companies? Thanks again! :)

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Bio: I am an AV and IT guy... I have been involved with sound and lighting since I was 7 yrs old. I currently do Information ... More »
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