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Wire-Lists #29: 4 Tips to Improving Your Wireless Signal To Noise Ratio

Social Media WireLists29 300pxSignal to noise (s/n) ratio is the level of signal power in relation to the power of noise surrounding that signal, measured in decibels (dB). With wireless systems, the quality of your sound is largely dependent on achieving the highest signal to lowest noise ratio possible. So how can we do this? First, we need to look at the cause and type of noise in question. "Noise" is any type of competing signal interference – unwanted tones, static, even other frequencies - within the physical space. If you’re using wireless microphones, your noise may also be a result of channel noise in the FM process. “FM,” because all analog wireless systems use frequency modulation to send audio signals. A component of the FM process is the Capture Effect: wireless receivers will always demodulate (turn into audio) the strongest RF signals within a given frequency, and that includes sounds that you don’t want.

In order to combat the noise, you’ll need to look at the physical space you’re operating in, which is your working environment and also any equipment in your environment. Four tips to consider:

1) Check the distance between the transmitter and receiver

In general, the closer transmitters and receivers are to each other, the better your signal. This is the Inverse Square Law at work. It states that the intensity of a radiated signal is inversely proportional to the square of the distance of the wave from the signal source. If you double your distance, the signal strength is reduced by a factor of four (and the reverse is true, too). When possible, use the least practical amount of unobstructed distance between transmitter and receiver.

2) Shielding

Are you getting interference from outside your venue or area? Walled structures, in combination with wireless mics, are effective shields against what might intrude from the outside, as RF does not easily travel through dense solids. Wireless mics are not without their issues – attenuation being one. We cover attenuation in Wired List #8. In extreme cases where you are indoors and still getting interference, and if you can’t change frequencies, look for sources of interfering RF and either shield them or increase the distance from them to your receivers (see #1).

3) Antennas

Directional antennas, when used correctly, can be used to improve s/n ratios. They should be affixed above head height (10 ft is a good rule of thumb), with a clear line of sight to the receiver. By orienting them so that their null sides are “pointing” at unwanted sources of RF (local TV towards, etc.) the RF s/n ratio is further improved. We published a list of common antenna combinations for our equipment in Wired List #12. If you're using coax cables to bridge distance, inspect them before use, as wear and defects can cause a loss of signal. All coax cables result in losses of signal strength, depending on the cable material and length. Some systems may benefit from in-line filters such as our PF 25 (Link to: ) or PF 50 or filter/amplifiers, such as our UFM144. In reference to this topic and to #3 above, a powerful tool for many systems is the ALP690 active/passive antenna with selectable amplification, attenuation, and filtering.

4) Increasing Transmitter Power

If nothing else works, you can try increasing your transmitter power. Be advised that this can often result in increased noise in the general RF spectrum, which might be counterproductive. Additionally, licenses are required in some localities to operate transmitters over certain thresholds. You can check to see who the licensing body in your locality is here. Our recent Wireless Side Chat series on YouTube are good primers to review if you’re looking to improve your signal quality, because we often don’t consider the technical considerations behind cause and effect. If you missed them, they are:

#1: Introduction to RF Spectrum for Wireless Microphone Use

#2: The 7 Most Common Wireless Mic Problems and How To Solve Them

#3: Wireless Designer Software New Features, Tips & Tricks 

#4: Wireless Side Chats

#5: More RF Best Practices

Wire-Lists #28: Five Tips for Troubleshooting Wireless Mics

Social Media WireLists28 300pxOne of the things that makes wireless microphones so great is what they don't have - wires! Working wireless gives artists with elaborate stage shows, like Pink, true freedom of movement on set. But as awesome as wireless mics are, they are not without issues. In this List, we'll discuss five common glitches that you might experience with wireless microphones (and their receivers) and how to fix them.

Blocked Signal

One of the most common problems with wireless mics is signal blockage. A wireless mic is a transmitter, and anything in a wireless set-up between the transmitter and the receiver can block the signal. The typical culprits are walls or solid/dense objects on set, so you may need to move your receiver, or your external antennas if you use them, around to find a line of sight path for the RF signal. The human body can also absorb signals, which can be problematic for belt-pack units if not placed carefully. Same goes for handheld mics: make sure that they are being held properly so that the antenna is not covered by the hand. We explain this in more detail in Wire List #8.


Bodyworn transmitters, such as you'd use with a lavaliere mic, depend on their antennas - that covered wire extending out - to deliver a signal. If the antenna is obscured or bent, your signal will be affected. Repeated stress, such as bending an antenna in the same spot, will break the tiny wires that make up the inner core of the antenna and render them useless over time. Our antennas are quite tough but with enough abuse, they can fail. Our transmitters have fixed-length antennas for specific frequency ranges, so always ensure that your antenna matches your frequency. We color-code ours to make it easy. If you are finding that your range is inadequate, consider using a directional or omni-directional antenna to boost the range. We offer several options depending on your specific need, and you can also make your own.

Noisy Audio

“Static” in the audio can be created when mic connectors are worn out, damaged, or corroded, or if there is moisture in the connector. Any movement can then create noise which is then transmitted. Be sure to keep your connectors clean, and if the metal parts become worn or the fit isn’t what it once was, consider having the connector replaced. We cover connector cleaning in Wire List # 5.

Accidental Setting Changes

Have you ever synched your mic, only to find that it changed settings again somehow and now isn’t syncd? Settings are often sent via IR, where the "window" of the transmitter is exposed to the emitter on the receiver. Usually, the range of these IR emitters is only a foot or so, but in just the right conditions, the reach might be further. To prevent this from accidentally changing the settings on one of your units, simply put a piece of tape over the IR window after you've synched. This will "lock" the setting and make sure that no other signal can change it. Just remember that the tape is there next time you use it! Tape is also useful for power switches. While our handheld has the power switch behind a sliding panel, other manufacturers have it where it can easily be toggled. A piece of tape prevents the switch from being accidentally bumped to the off position.

Interference and Intermodulation

If you are using Frequency Finder or another program to scan and choose your frequency, you may never experience interference. However, in today's crowded airwaves and when you are using multiple systems, it’s a possibility, in which case, you simply need to change your frequency for the affected units. Try switching your mic/receiver 2-4 MHz (do it in steps) up or down from where you were. Intermodulation, which we discussed in last week's Wired List, is when two or more frequencies interact, create new signals, and cause potential interference. You will frequently see this in large productions, when you have ten or more mics operating in a relatively small (frequency) space. Like too many people in one room that make it hard to hear conversations, intermodulation can be corrected by calculating for these interactions and planning your frequency occupation carefully among your connected units. This is an ideal use for Wireless Designer as you can see and keep track of all of your connected systems on one page. As you can see, most of these problems are easily diagnosed and just as easily repaired without needing assistance. Still stumped? This email address is being protected from spambots. You need JavaScript enabled to view it. or post a question on our Facebook page.

Wire-Lists #27: Advice for Navigating The Block 19/470 Overlap

Social Media WireLists27 300pxHave you ever been working with one of our systems in the 486-495 MHz range and they’re just not synching up? You might have performed a frequency scan prior to choosing your settings, so you’re sure you’ve chosen everything correctly. Or did you? You may have run into the not-common-but-it-happens Block 19/470 Overlap.

What Is The Overlap?


As we detail in our transmitter manuals, there is an overlap in the frequency range of 486.400 - 495.600 MHz. We designed this intentionally, in order to maintain compatibility with receivers that tune across a single band. The problem only makes itself known in specific instances where you are tuning within the A1 Band on either Block 470 or 19 and one device is set to block 470 and the other one is set to block 19. This can occur when the devices are tuned manually.

The Key To Sorting This Out: The Pilot Tone Squelch

Squelching is a way to mute receiver audio to discard noise when the RF signal is too poor to produce good audio. Our Digital Hybrid Wireless® receivers use pilot tones to ensure that the receiver is quiet when turned on and off and also to mute signals from other transmitters. Intermodulation (intermod) is the interaction of two frequencies that creates unwanted distortion. We designed our units to have a different pilot tone for each of the 256 base frequencies to prevent unwanted un-squelching when an intermod lands on a receiver channel. The overlap between blocks 470 and 19 within the A1 band means you can have the correct frequency specified, but since the transmitter and receivers are set to different blocks, the pilot tones, as indicated by your hex codes, don’t match.

When In Doubt - Check The Match

Occum’s Razor tells us that the simplest explanation is usually the correct one, and that holds here. When using a transmitter on the A1 band with a Block 19 or 470 receiver, be sure that the transmitter is set to Block 19 or 470 and check the hex code on the receiver to make sure it matches the transmitter. In the example shown below, they don’t match.

Lectrosonics and frquency ban

Checking this could save you a phone call or your gear an unnecessary trip to the Mothership. For other transmitter troubleshooting ideas, check our website’s Wired List #2.

Wire-Lists #26: Developing Sanitation Protocols for Lav Work:

Social Media WireLists26 300px4 Tips For Keeping It Clean and 2 Tips For Getting Back To Business And Staying Distanced

Keeping things clean has been a hot topic lately, and social distancing also looks like it will be here to stay for a while. Most of us use lavalier mics, which require touching the talent. As we start to get back to work, how can we adapt what is a very hands-on job to be more hands-off and give our clients the safety and peace of mind that they deserve?

The AQTIS and IATSE in Canada are in the process of writing sanitary guidelines for productions undertaken there. Written by Daniel Fontaine-Bégin, Tony Fortin, Simon Poudrette and Stephan Roy, the guidelines recommend:

1) Frequent handwashing, along with the wearing of masks and protective glasses, within 6 feet of talent. Surgical gloves should be used to pass things to others.

2) The placement, adjustment and removal of lavaliers should be done at the Sound Station, using fresh adhesive. 

3) As a general rule, a solution of 70% isoprophyl alcohol - either in a liquid or as pre-packaged lint-free wipes - is preferred for gear disinfection. That specific percentage is recommended because it takes more time for the liquid to evaporate from the disinfected surface, making it a more efficient cleaner than 91% or 99% alcohol. Mix the solution in a spray bottle, which produces a fine mist and disperses the liquid without soaking what it is sprayed on. Depending on the surface to be cleaned and the shape and size of the items to be disinfected, it may be possible to spray lightly, wipe or dab with cotton swabs. Bleaching solutions, such as Lysol or disinfectant wipes, are not recommended for any gear, since they can be corrosive. 

4) Assign a disinfected transmitter and lavalier microphone for each person and store it in a Ziploc-type bag, or appropriately-identified container. After the work day, disinfect and place in a new, clean labeled container for the next day’s use. If the production budget permits, appoint a "disinfection team" (one or however many people you deem necessary) whose sole responsibility will be to ensure clean gear and make safe adjustments on talent as needed.

Distance-Friendly Ideas

The nature of lavalier mics involves touch and adjustment.  You might consider these two workarounds to make it easier to maintain distance:

5) If you use our SM transmitters, you can adjust the transmitter remotely without touching the talent by using the LectroRM app by New Endian. It works with all remote-enabled SM series transmitters to control audio level, frequency, transmission power, low frequency rolloff, LED, sleep and lock functions. 

6) Perhaps you want to get away from using a lav altogether, which can be challenging for interview or close dialogue situations. Parabolic mics, which are often used in sports broadcasting, can allow a safe distance without compromising safety or using a sometimes-unsightly boom in the shots. We realize that parabolic mics may have limited applications in many kinds of production work. However, in places where they can work, our Digital Hybrid and latest digital transmitters are an ideal match, with low noise floor, wide dynamic range and flat frequency response. 

A Word About UV Disinfection

Many of you have asked us about UV light for disinfection, and we haven’t tested any UV methods thoroughly enough to recommend them at this time. Our Service Department is presently testing options, and we will share our findings when they are available.

Learn more in our Wired List on disinfection. As always, consult the CDC Guidelines, which are updated as they evolve

Many thanks to AQTIS and the Canadian branch of IATSE, who provided some of the suggestions for this list and are allowing us to participate in the development of their working guidelines.

We want to hear about how you are adjusting to our new ways of working. Let us know at This email address is being protected from spambots. You need JavaScript enabled to view it., or start a discussion on our Facebook page.

Wire-Lists #25: 5 Best Practices and Tips for Creating An Online Worship Experience

Social Media WireLists25 300pxThe times we’re living in are requiring all of us to come up with new ways of doing things, particularly when it comes to group gatherings. If you are a pastor, a youth leader or one who handles the technology for your worship center, this extends to the holding of services and study groups. How can you lead your congregation remotely, particularly if you haven’t done it before? Facebook Live, YouTube and even your own website can offer you a way to reach out – we’ll leave the choice of platform up to you. In this list, we’ll discuss the five considerations for creating a remote worship experience, regardless of platform.

  1. Schedule and promote your content
    Think of your broadcast as an invitational event. Let your congregation know when and where to expect it, and how to participate. Forward-thinking communication and the need for connectiveness to community are huge right now, and doing this will help build anticipation and an audience for your service. Your website is the obvious place to start, but you can also publish a schedule in any mailings or emails you are doing, along with sending texts and publishing reminders on Facebook, Twitter and any social platform you may use.
  2. Choose a location
    Different situations call for different environments, so think about the needs of your congregation and what they will most connect with. Perhaps the location will be your desk in the church office. Maybe it will be in your own home. Or you might want to broadcast from your own altar or pulpit, or even somewhere in nature. Find a spot that is well-lighted, with the emphasis on you. Check your background for anything that might be distracting, and either remove it or position yourself accordingly to hide it.
  3. Sound
    Depending on how you choose to record and whether or not you are broadcasting live, there are two ways that you can approach sound:
    a) Mic through computer, using the computer’s camera – You will get the best sound if you use a headworn mic, like our HM172 and its accompanying C172 cable clip. The clip will cut down on noise created by the cable rubbing against your clothing. Another option is a directional, shotgun/stand mic attached to your computer, positioned behind your monitor, out of view, yet facing you. In both instances, you will want to treat the camera as if it were a person and speak to it, minimizing instances where you speak to either side.
    A note for live broadcasts: If you are broadcasting through your computer, turn off any notification sounds, such as those for email or Facebook. They otherwise appear randomly and are distracting. Be aware of anything in your environment that you can likewise turn off, minimize or schedule around, such as your computer’s fan, pets, household noise and neighborhood noise (leaf blowers, mowers).

    b) Externally, using a camera or GoPro – This option is for those who want more freedom of movement and are broadcasting in a wider area, such as a local pastor in our area did when he recorded his Easter Sunday sermon and prayers outside, in the field outside of his church. His technical person filmed him from an appropriate distance, using lenses and angles to convey proximity. To capture his sound, the pastor used an MTCR   and a lav mic. The tech person then married the visual and the sound in post-production and made the “service” available online for later viewing. We discuss a similar technique in Wire List #21. You can also use our SPDR to capture sound.
  4. Music
    Music is an integral part of any worship experience. When broadcasting remotely and using recorded sound, be mindful of copyrights to the music you are using. Churches often have license to use copyrighted music in their services, but at the time of this writing, this may not extend to online use. There are a variety of sources you can use that are royalty-free, and other options include having soloists appear on camera in a small-screen or including a Zoom-like choir with people performing from their own locations. We have also heard about pastors creating Spotify playlists that congregants can play on their own.
  5. Disinfection
    Whether you are using your own equipment or gear borrowed from others, disinfecting them after use is a smart practice. We discuss how to best do this in Wired List #20.

Broadcasting services online offer your worship centers many possibilities that will extend past this pandemic period, including expanding your outreach to different areas, providing on-demand Scripture studies, and making services available to the homebound or those living in remote areas. We learned a lot about online broadcasting when we developed our Wireless Side Chats and are happy to help you troubleshoot yours or develop a plan. Reach out to us through our Facebook group or This email address is being protected from spambots. You need JavaScript enabled to view it..

Wire-Lists #24: Making A Coaxial Dipole Antenna With 6 Items, In 8 Easy Steps

Social Media WireLists24 300pxYou’ve undoubtedly run into situations where you need to get your transmitter antenna away from the talent’s body, or where you could use a few more feet of reach for your receiver. We make & sell these coax antennas as the ACOAXTX here and there is also a BNC version available as well – the ACOAXBNC.

That said, if you’re handy and have done a little bit of work with wiring, you can make your own! In today’s list, we’ll explain how to make a coaxial dipole antenna, using a few readily available tools and a pre-made cable.

6 Things You Will Need:

  1. A piece of shrink tubing, at least a foot long. This will be used to give a finished look to the antenna.
  2. A pair of wire-cutters
  3. A cable with an SMA connector at one or both ends, like this cable from Fairview Microwave
  4. Heat gun or hair dryer
  5. An X-Acto knife, box cutter or razor blade
  6. Optional but helpful: color-coded caps to finish the end of the antenna

The 8 Steps:

  1. acoaxtxFold your cable in half and cut it at the halfway point. This will leave you with two cables with connectors on one end. Each cable now has an antenna on the cut end, so you can make two dipoles from this one cable.
  2. The higher the frequency, the shorter the antenna. To figure out how long your antenna should be, download and print out our antenna kit guide to use as a template, or use the measurements shown on the sheet’s table to find your desired block’s measurement. Lay the wire flat and measure outwards from the connector. Do not cut through the wire.
  3. At the point you measured to, lightly “score” the outside insulation (the rubber cord coating) without cutting into the shield or wire inside. What you want to do is separate the insulation/outer coating on the cable without completely cutting it off. You might find it easier to use an X-Acto/box cutter/razor blade to do this, rather than your wire-cutters, and nick the material a little bit at a time.
  4. Carefully pull the shielded wires out from the insulation by folding the wire at the spot that you cut, making a loop and pulling it out. The wire comes out easily once you have it started.
  5. Straighten out your shielded wire while bending the insulation to the side.
  6. Take your shrink tubing and carefully slide it over the insulation and the shielded wire. Slide it down to where the connector attaches, leaving the wire exposed at the end.
  7. Use the heat gun or the hair dryer to shrink the tubing. This conceals the insulation and gives your dipole a more professional appearance.
  8. Color coded caps can finish the end of the antenna and make it easy for you to distinguish from others you may have or make. It’s always good to keep a few on hand. We provide 10 different colors in our A8U kit. You can glue the cap on for more security.

This process creates a versatile dipole antenna that can now be used with any of our transmitters that have SMA Connectors. They’re great for hiding inside or pulling through costumes in those scenarios where you need slightly better transmission. This same procedure works to make receiver antennas (length is not an issue with those). If you keep the necessary items in your bag, you’ll be able to fashion any dipole you need, on the fly.
If you prefer to follow along with a visual, see the instructional video on our YouTube channel.

Wire-Lists #23: Phantom Power with M2Rs and Other Receivers, plus 6 Best Practices

Social Media WireLists23 300pxThe M2R was designed originally as a personal listening receiver, often called an “IEM pack” (in-ear monitors) and thus, we used a very high-quality headphone amp for the design. The downside is there is no protection from 48V phantom power when the M2R is used as a camera hop receiver and is connected to professional microphone inputs. We have seen several M2Rs (and occasionally other receivers) come into repair with damage from this issue. This List will discuss what phantom power is, why it’s important, and how you should work with it to get the best results and avoid damaging your equipment.

What is phantom power and why is it important?

Phantom power, commonly designated as +48V or P48, is a way of sending DC current through an XLR cable and was designed to power these devices without using external power supplies. The power is sent through the same cable that is carrying the audio signal and leverages the multiple wires in a balanced-XLR cable to provide voltage to mics that need it (condenser mics, which have active electronics and require a voltage for polarizing the microphone’s transducer element) without affecting those that do not (dynamic mics). You can plug either type of mic into a mixer that provides phantom power and the condenser mic will use that power, while the dynamic mic will ignore it. That is why it’s called phantom – it lurks in the background for mics that need it, is invisible to those that do not.

When did phantom power become an issue with Lectrosonics equipment?

With some of our earlier generation receivers (specifically CR-series, which some of you might still use), the signal from the microphone was cut off until the phantom power was removed. Some customers didn't realize what was happening, thought their units were failing and needlessly sent them in. So, we modified our circuitry to add a resistive series into our receiver design to protect against capacitive discharge, along with resistive bleeders to ground to reduce peak voltages and non-polar capacitors for protection against miswiring. This works, although we do lose one or two output stages when outputs are wired to 110VAC.

Can phantom power ever damage my equipment?

As mentioned, although most of our equipment has since been redesigned to account for phantom power, it is important to know how phantom power may negatively affect microphones in older units (and this covers rental equipment or other scenarios you might encounter onsite) before you decide to use it. For example, some multi-channel preamps can only apply phantom power across multiple channels.

The situations that could potentially cause phantom power to damage a microphone include:

  • Shorts. Electrical shorting will send the phantom power voltage up one audio conductor rather than both. Even a quick/brief short can cause the DC voltage to enter the wrong parts of the microphone and damage it.
  • Sending phantom power to an unbalanced microphone. Phantom power requires a balanced connection to work properly. If phantom power is forced through an unbalanced cable to an unbalanced microphone, the 48 volts on the audio cable may overload and damage the circuit. Examples of unbalanced microphones include DC-biased lavs and karaoke mics. Older ribbon microphones like those made by RCA can also be damaged by P48.
  • Power surges and brownouts. Power surges can overload the phantom power circuit. The spike in electrical current can fry certain wires or components within the circuit. Power conditioners are always a good idea, and although we don’t endorse one vendor over another, Furman is one most of you will be familiar with.

6 best practices when working with phantom power

Phantom power is not just a microphone phenomenon! There are some other devices like preamps and direct boxes that require a small amount of power to function, hence the presence of phantom power. These devices can often be powered by batteries, but many of them are designed to function using phantom power. Here are six best practices when working with phantom power:

  1. There is a warning in the M2R manual: “WARNING: If connecting this receiver to microphone inputs, such as in a camera hop arrangement, 48V phantom power MUST be turned off. Otherwise, damage to the receiver will occur.” We cannot stress the importance of reading your product manuals, especially for warnings of this nature.
  2. If you are unsure whether or not the device you are connecting with may have P48 present, use a phantom power blocking cable made specifically for this purpose. ACE Cables is one good source. If you choose to use this option, please be mindful of their disclaimer, which reads, “Phanton power block cables are fitted with passive components to protect from phantom power. An initial voltage spoke will occur when phantom power is turned on. Whenever possible, plug the XLR connnector in first, wait 5 seconds for the internal bleeder resistor to reduce voltage, then plug 3.5mm connector in. Components have an estimated 2,000 hour life. Periodically test cables with a voltage meter to ensure correct function.”
  3. If possible, only plug/unplug all mics when global phantom power is off. “Hot patching” (plugging-in and unplugging patch cables) is not advised while phantom power is engaged.
  4. Always mute your outputs/channels to avoid speaker- or headphone- (or ear)-damaging pops when plugging/unplugging mics with phantom power on or when turning phantom on/off.
  5. If you have to use a modern, balanced output ribbon mic with global phantom power, make sure it's plugged in before turning phantom on.
  6. Don't use a patch bay when using global phantom power, or make certain that phantom is deactivated when patching. Shorting 48V to ground is not a good idea for any mic.

Working with phantom power on the M2R or any of our receivers shouldn’t be a mystery. Still have questions? This email address is being protected from spambots. You need JavaScript enabled to view it..

Wire-Lists #22: 5 Steps To Getting The Most Out Of The Broadcast Loop

Social Media WireLists22 300px The next time you're watching the news or a live narrative-type program - pay attention to the person speaking. You might notice their lavaliere mic, but more importantly, how it is placed. Chances are, it has a loop in it, with the mic head pointing up or down. Called a "Broadcast Loop" or "Newsman's Loop," this technique and mic head placement is effective for specific scenarios and, when hiding the mic isn't the main priority, can fix some common audio problems.

Why Would We Use A Loop?

The most obvious reason why you might arrange a Broadcast Loop is for esthetics and ease of movement. A lavaliere cord draping down the talent's chest is visually distracting, and the cord can get caught on things as the talent moves about the set. The loop addresses this by making only the mic head and the loop visible to the camera/eye (the remainder of the cord would be hidden under clothing).
The more important technical reason as to why you would use one is to preserve sound quality. A lav mic on talent offers closer audio than a boom mic, but by the same token, lavs notoriously pick up every bit of sound around them, particularly crunchy rustles from clothing and skin contact. Any movement of the cord can result in noise traveling up the cord (which your techs will mistake for static/interference in your signal). The Broadcast Loop creates slack in the cable at the lav clip, so if the cable moves, the slack creates a vibration-diffusing buffer. The orientation of the mic head can improve your frequency response and the quality of the sound you capture.

5 Steps To Mic and Loop

Most lapel-worn mics have a jawed attachment that resembles a tie clip, and some models have accessory hooks to help you fashion a loop. If you're using our M150 or M152, for example, the C-150, will also hold the cable for you.

  1. First, power up your transmitter and test the mic before placing it on the talent. Be sure the battery is fresh. Wipe the cord with some baby oil to keep it pliable and cut down on cable noise.
  2. Place the tail end of the lav cord on the talent, out of immediate sight. Hiding the cord is an art onto itself and most techs have their favorite ways to do it, but your main goal is to place it where it can be easily connected and disconnected to your transmitter and where it will not be in the way of free motion. Some techs prefer to hide it under clothing or tape it to skin, while others place it under jackets or around the talent’s torso.
  3. Next, consider the acoustics of your environment and the sounds of the talent themselves. Does the room have an echo or any audible ambient noise? Take a few minutes to listen to your talent's speech and breath patterns, relative to the room you're working in. This is a necessary step, even if you work with the same people all the time, because situations like allergies, emotions and dry mouth can alter a person’s normal speaking patterns. The things you are looking for are sibilance (the hissing "s" sound that is noticeable with higher-pitched voices), plosives (hard B,T and P sounds), and hard in/exhales, all of which can cause distortion and wind-like noise. If you notice these, you would address them through how you direct the mic capsule.
  4. Check the direction that the talent will primarily speak in. A reporter will speak directly to the camera, while someone on a panel might turn towards the moderator or other participants and a pastor might speak in a sweeping motion across their congregation. In the case of multiple speakers, you may have one that is much louder than the others. So, you would clip the lav on either the left or the right lapel area, or in the case of a forward-facing speaker, in the middle of their chest. You are aiming for a natural, well-balanced sound.
  5. Clip the lav to the talent’s clothing. If the clip has a hook built in, you would simply hook the lav head into it.
    If it does not have a hook, you will use the jaws of the clip to hold it in place. Open the clip, then loop the cord into a teardrop or circle shape and trap it between the fabric and the jaws of the clip. Although clipping the cord might go against your normal best practices, mic cords are designed to be used this way. The mic head can then be swiveled to point upwards (in the case of a forward-facing speaker) or downwards (accounts for speech patterns), depending on the sound you're compensating for. The end result will look something like this:

Photo of lav loop

The Broadcast Loop is an old-school technique that can offer some tangible advantages when working with today’s highly sensitive audio equipment. Need additional pointers for your unique situation? Reach out to us by email or on our Facebook group.

Wire-Lists#21: The #1 Way To Get Flawless Wedding Video Sound With MTCR

Social Media WireLists21 300Videography is one discipline where sound and visuals converge, and while it is not exactly new, wedding videography remains one of the most profitable projects that videographers undertake. And the demands for it are more stringent than ever before. No longer are wedding videos a simple chronological record of the day – they have become dynamic films featuring cinematographic camera work and even soundtracks. One of the newest trends is to show a “trailer” containing moments from the ceremony during the reception, which means that the footage needs to be edited an hour or two after filming and most likely onsite! With all of this going on, someone (that would be you) has to be mindful of the most important reason why everyone is there on the day: to witness the vows. The videographer has to figure out the best way to obtain a clean audio track while at the same time being unobtrusive and inclusive of more than one camera set-up. Many videographers plant mics throughout the venue or have the partners speak into wireless mics, but this isn’t always practical, feasible, esthetically pleasing to watch and in cases where the wedding is in a church with strict requirements, might not even be allowed.

Enter the MTCR. This is exactly the type of application that we developed it for. Similar units are already used extensively in reality TV and live action documentaries, and in a sense, these applications are not much different than what you are trying to accomplish.

The MTCR runs for over 6 hours on a single lithium AAA battery – plenty of time to capture a typical wedding ceremony and beginning of the reception. If you are using timecode to sync cameras and audio, the MTCR can be jammed to your camera’s external time code via the standard 5-pin Lemo connector. And it is small enough to be hidden in the most form-fitting wedding gown or tucked neatly into the breast pocket of a tuxedo.

If you are new to using this method, the steps are:

  1. Mic one of the partners with a MTCR and lav the morning or afternoon of the wedding. Usually, you’ll mic the groom, and the MTCR can go in the suit pocket, while the lav is clipped to his lapel, maybe 6 or 8” below his chin. Don’t forget wind protection! You will set the gain and volume in advance and jam with timecode that syncs with your camera(s). It is usually unnecessary to mic the officiant, as his or her voice will come through clearly on the mic. All three people are within a few feet of each other, and usually it is very quiet during the ceremony. In post editing, you would compensate with a “fill left to right or right to left” command to put the one mono track onto both tracks of the stereo audio. You may have to ride levels just a touch to compensate for the difference of distance between the people speaking and the mic.
  2. Enjoy the event.
  3. Remove the MTCR after the event or during a point in the reception where it is convenient to do so.

At the end of this exercise, you will have a microSD card with clean audio. In your editing stage, you would then choose “synch by timecode” or the similar command within your software, create synced groups with every angle’s action lined up with sound, and start editing immediately. If not using timecode, most video editing software offers a “sync to waveform” operation which aligns the audio tracks based on a reference, such as from an on-camera mic.

So whether you’re recording a solemn event or a real life reenactment of Tony and Tina’s wedding, the MTCR is a foolproof way to ensure that your wedding videos sound as perfect as they look.


Wire-Lists#20: Equipment Disinfection

Social Media WireLists20 300pxMany of you have asked us about the best way to disinfect your equipment and work safely in light of the current health situation we're all navigating.

The first things you should review prior to anything else are the CDC guidelines, which are updated as the information evolves. These are official government health guidelines and will take precedence over anything that we will tell you, now or in the future.

This situation also offers you an unplanned proving ground - a silver lining to this, if you will. If you're working right now, our wireless technology will allow you to maintain more distance from your subjects and a wider circle of personal space than you may normally need, and you will still get great sound.

Our Five Recommendations

In general, alcohol is our friend. Bleach or Lysol solutions are not recommended, as they can be corrosive. The solution we've made in our shop consists of 16oz. of 91% isopropyl alcohol plus 4oz. of water (which makes a 70% alcohol solution), mixed in a 32oz. spray bottle. Look for a spray bottle with a fine mist that will disperse the solution without soaking what you are spraying. You can also use 70% alcohol packaged wipes, as they are lint-free and save you from the worry of accidentally spraying or dripping solution into the equipment. Depending on the surface to be cleaned, it can be lightly sprayed, wiped or dabbed with Q-tips. Our general guidelines:

  1. Remove any batteries and disconnect power cords prior to cleaning.
  2. Wear rubber gloves when cleaning equipment, and discard the gloves after use. Do not reuse the gloves, as the virus can survive for a time on many surfaces.
  3. Likewise, use disposable lint-free cloths/wipes/Q-tips and do not be tempted to reuse them.
  4. Clean in an open area with good ventilation, alone or around minimal people, observing the 6' social distancing protocols.
  5. Once equipment is disinfected and is dry, you can keep it in Ziploc bags to ensure that it remains disinfected until you are ready to use it. Ensure that the unit is fully dry, then put it into the bag and squeeze out all of the air before closing. 

Cleaning for specific equipment

Lav mics: Wipe down the cord and head with the solution and a clean cloth. If the lav has a foam head (headbasket), remove it, lightly spray it with the solution and let it dry. You can then clean the head with a Q-tip. 

"Invisible" face-contacting mics: As these contact the skin and body and are in the breathing trajectory, wipe the surfaces with the solution and a clean cloth. 

Cords/antennas/power supplies: Wipe down with the solution and a clean cloth.

Transmitters and receivers: Wipe down with the solution and a clean cloth. You may also carefully clean the terminals and switch areas with a Q-tip, lightly moistened with the solution. Take care not to drip liquid into any of the openings.

Carry bags: As these are a fabric-like woven material, lightly spray with the solution and allow to dry thoroughly. Do not shake bags, as this can cause any viral particles to disperse into the air.

This is good information to have handy, even after this situation resolves. Many of you in broadcast work in environments such as medical news, crime scene, war zone or documentary, where maintaining cleanliness and safety are challenging. If you have any questions about proper disinfection of your equipment, email us at This email address is being protected from spambots. You need JavaScript enabled to view it., or reach out on our Facebook group. Although our business operations are currently suspended, we have a remote crew of Fanatics monitoring the email box and Social media, available to help you in a timely manner.

Stay safe out there!

Wire-Lists#19: ETSI standards, 75 and 50 kHz Deviation for Transmitters, and You

Social Media WireLists19 300pxAlong with the re-allocation of TV Frequencies in the US that were finalized in 2018 (and going into effect through July, 2020), regulations also have changed regarding the deviation of all new wireless microphone transmitters to a maximum of ±50kHz. For any questions about the spectrum re-allocations, repacks and new services in the 600 MHz band, see our page FCC & Spectrum Updates.

Since these changes were announced, many of you have called and written us, with understandable confusion: “Do I have to buy all new equipment?” “Is there any way that I can modify what I have?” This week’s post explains how this situation came about and what we and the industry have done/will do to make it easier for you.

* We are discussing transmitters and not receivers because only transmitters have a legal cutoff.

What Is Frequency Deviation?

For starters, frequency deviation is used when discussing audio, to describe the maximum FM modulation of the nominal carrier frequency. The transmitter pulls the frequency away - both above and below - to signal an instantaneous analog value proportional to the difference from the presumed carrier frequency. The amount of differential is called the frequency deviation, and the larger the differential at the beginning and end, the larger the presumed baseband (audio) signal is. In practice, the deviation is limited to a specific amount (according to FCC regulations) to preserve the bandwidth and bleed over into adjacent FM channels. The modulator is limited to a maximum permitted deviation.

Why And How Did All This Come About?

ETSI is the global standardization organization for Information and Communication Technology (ICT) standards, and it affects how we design and manufacture our products. One of the specifications standardized by this organization is known as the “ETSI Mask,” referring to the occupied bandwidth of any radio transmitter, and the shape that that signal is allowed to have.

Starting on October 1, 2018, American manufacturers and dealers of wireless microphone systems were mandated to market devices operating with a maximum of ±50 kHz deviation, and conform to the ETSI Mask. This was to align the US with EU standards that have long been in place.

The FCC did not set the new final specs until July 2017 - the original specs (announced in 2015) were impossible to meet for a battery powered design. The four major manufacturers (Sennheiser, Shure, Audio Technica and Lectrosonics) who were actively engaged with the FCC appealed various aspects of those frankly unattainable specs (including power, deviation, spurious emissions, etc.) in December 2015 and did not get a final answer until the following July. We were already doing R&D for the wideband tuning units in 2015. By the time the final regulations were agreed upon, our wideband units were already being lab-certified.

As a result, any transmitters manufactured or sold after October 18, 2018 have conform with the new regulations and also must, regardless of previous testing/certifications or modulation/deviation of pre-existing models, be retested and re-certified under the new rules (the ETSI mask). We re-tested and re-certified 13 unit models (SM Series, LT, LMb, SMWB Series, SSM, HMa, HHa, and IFB T4) and the FCC issued new acceptance numbers for them.

How Does This Affect Me?

The difference between the ±50Khz deviation and ±75 Khz is not as critical as you may be concerned about. In a quiet/sound neutral environment, when you are challenging your gain, you might hear a difference. In the vast majority of circumstances, you won't hear anything - or it won’t matter. For example, the 941 band units are already at ±50Khz since their inception in 2018.
Here is a case-by-case evaluation, depending on what units you have:

  • Units that can be re-blocked will be done so under the new deviation standards and will have new FCC Id’s. Older legacy units that were not re-certified by Lectrosonics certifications are ineligible for reblocking. We can, however, continue to repair and service the units unless the RF circuit board is unsalvageable.
  • We cannot reblock the following: All UM and UH Series transmitters, all MM400s, SM, SMa, SMDA, IFB-T1, IFB-T2, LMA, HH, HM, IM and all UTs.
  • New or reblocked transmitters will be fully compatible with most of your current receivers (UCR411a, wideband Venue, Venue 2, SRB, SRC, IFBR1a, LR). It's all a matter of the mode selected; you don't have to replace your entire inventory. There is already firmware available to add the Nu Hybr mode to most of the older receivers (excepting the original 2 block Venue).
  • New firmware includes a compatibility mode, “NU Hybr,” (Max ±50 kHz deviation) which replaces the former “NA HYB” (Max ±75 kHz) mode. For the best operational results in your matching receiver, set the compatibility mode of the receiver to either NU HYB or EU HYB (they are equivalent). Many of the receivers already have the EU mode. If your receiver cannot be changed to this mode, have your serial number and receiver model available and contact the Service Department to determine your best option.
  • Users keep using the ±75Khz (“NA Hybrid”) units , as they are regulatorily grandfathered. We just can't make or sell new ones.
  • Current devices using ±75 kHz deviation will still be allowed, but will only work with legacy ±75 kHz devices.
  • If you have a ±50Khz transmitter and ±75Khz receiver, you can still use those. However, you will have better results (lower noise, better range) by changing the receiver over to either the EU Hybrid or NU Hybrid mode. We’ll explain modes in a minute. Crystal-controlled units and those in the 200 series, which many of you still have and use, will not work with the new modes.
  • Can you still get your 600MHz units reblocked if you’re late to the party? Yes - if they are on the listed of continued models. They will then conform with the new regulations and you’ll just set your receiver to match accordingly. Eligible units include SMV, SMQV, IFB-T4, HHa, HMA, LT, LMB, SMWB, SMDWB, HHA, SSM, and WM. Call our Service Department regarding any other models.
  • The new 941 band units are already designed and certified under the new regulations and sound great. No action is required for them.
  • The D4T is Part 15 in a different spectrum class (902-928 MHz) - no action is required on your part.
  • Venue 2 has no issues – it has always had both NA and EU Hybrid modes. Recent firmware updates include the NU Hybrid mode, which again, is equivalent to EU Hybrid.
  • The SMWBs and SMQV/SMV family units were formerly ±75kHz (blue ID badge) in the US and have been changed to ±50kHz (black ID badge) for compliance. Firmware will be available to limit the deviation, if desired.
  • We are happy to offer re-blocking service for any eligible affected units, at approximately 1/3 to 1/2 the cost of new. Please consult the re-blocking price list for further details. For any questions about re-blocking or to schedule your products for this service, please contact us at 800-821-1121 or This email address is being protected from spambots. You need JavaScript enabled to view it.

So why has it taken years to get to this point? First, we were told to stop building to the old specifications as of October 2018. We could not build the ETSI mask into the transmitter before that because, as explained above, the new specs were not finalized until last July – we had to redevelop what we were working on (more than once…) to meet the specs as they changed. The test labs responsible for certifying these units also had to learn the new specs and develop verification testing procedures. Additionally, the FCC won't allow a new spec transmitter to have both types of modulation available or selectable. We intentionally waited to make any announcements about our products until we were confident of the new rules and had solutions for our customers lined up and available.

How Can I Tell Which Units I Have?

If the unit has a stick-on metallic label as opposed to the designations being engraved on the housing, you can tell the older units from newer ones by examining the FCC ID on the label. The old (±75kHz) units have a blue label and the new (±50kHz) units that have been re-designed and re-certified have black labels and a slightly different layout:

Black and Blue Label

The newer units have an FCC ID that contains an "A" after the band designation.  Let’s use the LMb as an example:


  • FCC ID "LMBA1" is LMb in A1 band with ±75kHz deviation
  • FCC ID "LMBA1A" is LMb in A1 band with ETSI mask compliance and ±50kHz deviation.

In SMWBs, the single and double-battery models are electrically identical and share the same FCC ID. The older models use the single battery model number as the FCC ID, but the newer models use the double battery model number. The above logic still applies:

  • FCC ID "SMWBA1" is SMWB (and SMDWB) in A1 with ±75kHz deviation.
  • FCC ID "SMDWBA1A" is SMDWB (and SMWB) in A1 with ETSI mask compliance and ±50kHz deviation.

For block-wide units, the naming system has also been revised. The older units shared a common FCC ID for several blocks. A band designator of E, L, M, or H corresponded to bands A1, B1, C1, and D1 respectively. Now, each block gets its own FCC ID:

  • FCC ID "DBZWML" is a WM in block 21, 22, or 23 with ±75kHz deviation.
  • FCCID "DBZWM21A" is a WM in block 21 with ETSI mask compliance and ±50kHz deviation.

Considerations For Export Dealers

If you are an export dealer (depending on your country’s regulations), it is still possible to order former US spec models (with ±75 kHz deviation), in Bands A1, B1 and C1, in all frequency blocks, with the following understanding:

  • The units are ONLY sold outside the US;
  • The units have new model numbers to distinguish them from US versions. As of this writing, there is an “X” added to the model for “Export,” such as SMQV/X-22 or SSM/X-B1;
  • A minimum production run for us is five (5) pieces per model on any specific block or band. This doesn’t mean that you have to order 5 at a time, but it does mean that orders for fewer than 5 will need to wait until the in-house orders for that block/band total at least 5 before they can be produced. Lead time varies; feel free to ask if timing is a concern;
  • These products will have different firmware than the US units and no FCC markings. The technical data sheets and manuals address ALL models, though the firmware for the models will be different. Please pay attention to the documentation, especially where firmware is concerned. As mentioned in a previous Wire List, incorrect firmware being installed is the root cause of a fair amount of what we see in Service;
  • When market demand slows or parts become unavailable for any older model, we will cease manufacturing on a case-by-case basis. You will receive advance notice of this situation as we forecast production demand.
  • Models for E01 (Europe), E02 (Japan), E06 (Australia) and E07 (Canada) will continue to be available in all blocks and bands with no changes. If you have a customer who needs one or a few transmitters and doesn’t need high RF power (E01’s max RF power is 50 mW), then the E01 version will be the easiest to get/most available. Double check the regulations in the country of use before you order.

All of this is brand new territory for anyone involved in the audio industry, so you are by no means alone if you’re overwhelmed or confused. We’re happy to answer any further questions you have regarding the standards, the deviations or how they relate to your equipment. Give us a call or send an email – we’ll be happy to discuss it with you.