We love audio and you should too. Not having good sound can make or break an entry into a film festival, disconnect your audience, or generally piss people off because they can’t hear what’s being said.

There’s a plethora of audio manufacturers out there who make quality products but none do it quite as advantageous for the user as Lectrosonics. The company has been around since the 1970s building a trusted name among sound professionals with their line of wireless transmitters, receivers, and IFB systems that cater to production sound and music.

We’ve used a lot of Lectrsonics hardware over the years with great success and recently asked them to review the L-Series (ZS-LRLT) wireless kit. They were kind enough to send one out. Here’s what we found.

Lectrosonics_lseries_1L-Series LR receiver w/ camera mount and LT transmitter

First Impressions

The Lectrosonics L-Series (ZS-LRLT) kit comes with everything you need. Of course, there’s the LR receiver, LT transmitter, and a lavalier mic, but the company dropped in a camera shoe mount for the receiver, a belt clip for the transmitter, a TA3F to XLRM, and a TA3F to 1/8” TRS cable, batteries, and a pouch to carry it all. There’s nothing more frustrating when buying a “kit” only to turn around and buy additional accessories. Here, this is not a problem.

LT Transmitter

At first glance, the LT transmitter looks like a beefier version of their smaller SSM, SMV, and SMQV transmitters, and for all intents and purposes...it is. It feels rock solid.

The housing is machined aluminum with dimensions of 3.2 x 2.4 x .9 in. (81 x 61 x 20 mm) and a weight of 5.8 oz. To put that in perspective, it’s nearly identical to the Sennheiser SK 100 G4 bodypack transmitter at 3.2 x 2.5 x 0.6" (82 x 64 x 24 mm) and 5.6 oz.

There’s a lot to like about this transmitter. It’s part of the Lectrosonics Digital Hybrid Wireless series which is how the wireless signal is sent and how the transmission overcomes channel noise in the system.

For the uninitiated, there are generally two ways manufacturers transmit a wireless signal: analog or digital. An analog system can be either VHF or UHF with the latter being the better choice for a number of reasons but the main one is its ability to penetrate through walls. It’s why cellular companies are buying up huge chunks of the wireless spectrum from the FCC.

Analog systems like those from Azden or Sennheiser use compandors to extend the dynamic range (which can introduce artifacts). Digital systems, like those from Zaxcom, transmit audio 100% digitally so no companding is needed but it can sacrifice operating range.

LectrosonicsLT Front Panel

Digital Hybrid Wireless can be looked at as a combination of the two. It digitally encodes and decodes the audio but still sends the signal over the analog airwaves. Basically, Lectrosonics is trying to deliver the best sound over the best signal. But keep in mind all wireless suffers from channel noise; there’s no perfect solution yet.

On the front of the LT is an LCD and the same membrane menu controls we’re used to seeing from the company. This is a nice feature: once familiar with the controls, you won’t need to “re-learn” a new system when jumping from one Lectrosonics transmitter/receiver to another.

The menu has options for frequency selection, turning on or off the RF for standby modes, gain adjustments, line in or instrument in options, roll of, transmitter power selection of 50mW or 100mW, phase, locking and battery type, among others.

There’s also a menu option for different compatibility modes. Depending on the mode selected, e.g. “100 Series,” “200 Series” or “IFB Series” allows it to work with other Lectrosonics hardware. When in “Mode 3,” “Mode 6” or “Mode 7” it can work with hardware from other manufactures like Sennheiser.

The LT also features a removable antenna which is a big bonus. The antenna is usually the first thing talent grabs when they want to remove the transmitter and being able to easily replace it if one gets damaged is ideal.

LectrosonicsLT Battery Compartment & Belt Clip

Rounding out the rest of the transmitter are the 5-pin audio input for the lav, modulation indicator, infrared port, a battery status light, a programmable function switch that can be designated as a power or mute switch, a talk back option or it can be disabled.

A USB port updates the software and then you have the belt clip mounting holes and battery compartment which located on the left side. The LT runs off 2xAA batteries –alkaline, lithium, or rechargeable are all compatible. Depending on the settings and battery type, you can get 4-7 hours of operating time.

LR Receiver

The LR receiver comes in at 3.21 x 2.45 x .84 in. (82 x 62 x 21 mm) and weighs 7.1 oz. It’s built from the same rugged aluminum housing as the transmitter making it rock solid. Meaning, you should have no problem if it's accidentally dropped from 6-8 feet.

LectrosonicsLR Front Panel

It’s also packed with great tech. To suppress interference during the wireless transmission the LR uses front-end filters: when the operating frequency changes the filters re-tune to stay centered. There’s SmartSquelch to optimize the receiver when the signal is weak. SmartDiversity to determine phase switching. Smart Noise Reduction (SmartNR) to reduce hiss. And Test Tone.

Test Tone is one of our favorite features on the receiver. It allows you to match the audio levels of your equipment. A 1 kHz test tone is sent from the LR into your hardware and the output level can be adjusted from -50 to +5 dBu in 1 db increments. When setting up your system we highly suggest doing this step to maximize the signal to noise ratio.

LectrosonicsLR & Canon 5D Mark III Tone Test

To perform the Test Tone:

  • Connect the LR to the camera/device
  • In the LR menu select "Audio Level"
  • To send the 1 kHZ tone push "Menu" and the "Up Arrow" simultaneously 
  • Go to the camera/device audio settings 
  • You will see the tone being sent to the camera 
  • Finally, adjust the LR dBu setting using the "Up Arrow" or "Down Arrow"

LectrosonicsLR & 5D Mark III Tone Test

For our setup, we used the Canon 5D Mark III. To get the best signal to noise ratio we put the "Sound rec." menu option to "Manual" and the "Rec. level" eight clicks from the left. Then on the LR, we set the dBu level to -10. It's important not to maximize the audio levels on the 5D as the camera does not have a limiter. Pro Tip: If your camera/device does not have a limiter we suggest adjusting the audio levels 3-5 dBu lower in the settings. 

Like the LT, the LR has a similar menu tree with additional options including a SmartTune RF scan that automatically finds the best frequency channel for the area and an IR sync function that pairs the selected frequency to the transmitter automatically. Other menu options include the ability to create frequency tuning groups that can hold up to 32 channels, frequency step sizes of 100 kHz or 25 kHz, polarity and the aforementioned SmartNR.

Also on the front are RF link and battery status indicators. On top is the TA3 male (mini XLR) that provides balanced or unbalanced audio from mic to line level. Then we have two articulating removable antennas.

The LR is powered by 2xAA batteries, and again, alkaline, lithium, or rechargeable are all compatible. Settings and battery type can yield 3-6 hours of operating time.

LectrosonicsM152/5P lav mic

Lavalier Quality

The kit comes with an M152/5P lav microphone and includes a windscreen and tie clip. It’s an omnidirectional polar pattern so you’ll get good response directly and off axis with the mic capsule. It has a wide frequency response measuring 20Hz to 20kHz with a bump near 10kHz and a dip around 50Hz.

The lav produces a good neutral sounding voice. We would say it’s slightly better sounding the Sennheiser’s ME 2-II lav but only if you have a good ear. If you’d like to bump the quality of the lavalier we’d suggest a Sanken COS-11D, DPA 4060 series or a Countryman B6.

Frequency Range & Wireless Setup

The L-series comes in three different frequency ranges:

A1 470.100 – 537.575 MHz
B1 537.600 – 614.375 MHz
C1 614.400 – 691.175 MHz

Of the three kits, the only two to consider in the U.S. are A1 and B1. Version C1 is being discontinued in the U.S. as it spans the 600 MHz wireless spectrum which was sold at auction. If you’re outside the U.S. C1 is still an option. If you don’t own any Lectrosonics equipment we’d suggest A1 to future-proof yourself. If the FCC does sell more of the spectrum the next logical range would be 500-600 MHz.

LectrosonicsSmartTune finds the best frequency automatically

Setting up the wireless is simple:

  • Powering up the LR and LT
  • In the LR menu select "SmartTune" (the device will find the best available channel)
  • Once the frequency is selected, press the "Up Arrow" to start the sync
  • Line up the LR and LT IR ports up and the LR will automatically send the info to the LT
  • You're ready to mic and adjust levels

Lectrosonics also offers its free LectroRM mobile app (iOS or Android) that allows you to remotely configure the LT. This is a nice feature if you want to adjust the settings after already wiring your talent.

In the Field

As a whole, the kit performed extremely well in the field. Sound quality was excellent. Weather won’t be a concern but direct sunlight did make the displays a little difficult to read – but then again, what display not touting 500 nit works well in direct sunlight. We did notice the LT becomes warm to the touch but nothing alarming. 

We completed three different tests to push the range of the L-series: one in the interior of a busy mall, another outside surrounded by buildings and an open field test. For each test, we scanned for a new frequency and set the power to 100mW.

Interior Mall
With the receiver mounted on the camera and stationary, we walked the transmitter in a straight line testing clarity, interference, and overall quality. We were able to reach 528 feet before the transmission started breaking up.

Exterior Buildings
For this test we were outside in a promenade area with structures and buildings blocking the line of sight from the transmitter and receiver. We walked the transmitter testing its overall quality and reached 792 feet before the transmission started to break up.

Outside Open Field
In the final last test, we wanted to see how far we would reach without any interference of walls, buildings, or other wireless in the area. We found an open field and we hit 1,320 feet before the transmission starting showing issues.



We’re completely impressed by the L-Series kit from Lectrosonics. Everything from the build of the devices, the easy setup, and advanced features are all outstanding. Even the small things like the detachable antennas and providing both XLR and 1/8” cables inside the kit goes a long way.

Another big advantage is its compatibility among other Lectrosonics hardware and different manufacturers. Being able to mix and match Lectrosonics transmitters and receivers makes workflow easier. Plus, if you add an additional transmitter into your kit like the SSM you can use the LR as the receiver instead of buying another one (unless of course, you need to run two separate channels of audio).

Lastly, we’re floored by the range. Different areas will produce different results, but if you’re able to achieve 500 feet in a crowded indoor location without any interference or audio loss – that’s professional quality you can lean on for any production.

L-Series (ZS-LRLT) Kit Includes :

  • LR receiver
  • LT transmitter
  • M152/5P lavaliere mic
  • Camera shoe mount
  • Beltpack clip
  • TA3F to XLRM cable
  • TA3F to 1/8" TRS cable
  • Carrying case
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