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Lectrosonics 400/411A Series Wireless Systems

Since the mid 80s, Lectrosonics has been providing wireless technology to the film and television industry. Their first products in this market were notable for their simplicity, reliability, excellent build quality and affordability. (In fact, I still use some of their VHF units from this era for PL back from my boom ops on the floor. Solid performers that keep on ticking.)

Since the mid 80s, Lectrosonics has been providing wireless technology to the film and television industry. Their first products in this market were notable for their simplicity, reliability, excellent build quality and affordability. (In fact, I still use some of their VHF units from this era for PL back from my boom ops on the floor. Solid performers that keep on ticking.)
Product PointsApplications: Field, broadcast, film, live sound

Key Features: UHF system; 256 frequencies; Digital Hybrid technology; Smart Squelch squelch; Smart Noise Reduction; limiter

Price: UCR411A – $2,575 UH400 – $1,090; UM400 – $$1,250

Contact: Lectrosonics at 505-892-4501, Web Site.
As my primary wireless systems are from another manufacturer, I had not taken a really close look at developments in the Lectrosonics line for some time. Also, we recently had a burglary making the need to evaluate the current SOTA in wireless more pressing, so, when the magazine asked me to do a review on the 400 series equipment, I was up for it.

When it comes to wireless microphone equipment, I consider several key issues:

How does it sound?

How is the RF?

How well is it built?

What is the compatibility and convenience of the overall physical design and application?

What is the accessibility of the company for support and discussion?

What are the price/performance issues?

Only a few products can really stand up to this gauntlet of expectation and I believe the Lectrosonics UCR411A ($2,575) receiver and 400 series transmitters are now in this group.


Upon first inspection, the hardware looks very much like all the earlier, ubiquitous Lectrosonics designs and indeed uses the same robust baked powder black finished cases, connectors and battery implementation we have all become familiar with. I also appreciate the engraving of primary operation instructions right on the case metal of the receivers. I wish more manufacturers would be as considerate.

Appearances aside, under the hood of these machines are some very new things. There has been a design paradigm shift to the DSP model. The company is calling this “Digital Hybrid Wireless” as they are using DSP in both their transmitters and receivers while transmitting in the FM analog realm. At first, I thought this meant that they were sending ones and zeros over the air, but in fact, the digitizing occurs within the DSP engine and is sent as proprietary encoded analog audio to be decoded in the DSP at the receiving end.

Further advances have been made in Lectro’s pilot tone/squelch/muting scheme, enhancing differentiation from frequency to frequency regardless of some bully RF signal landing on the carrier frequency of the system. Without the correct pilot tone, the receiver will stay muted. Lectro is calling this Smart Squelch and says it waits for words or syllables to complete before squelching and significantly enhances the usability of “otherwise unusable signals.” These units are frequency agile with 256 frequencies available within the 25 MHz spread of the individual system. They use the traditional Lectrosonics block system for frequency identification.

Lectrosonics’ literature tells us the transmitters have “digitally controlled” analog audio limiter with a dual release (fast/slow) envelope. There is a 30 dB range with this limiter. This limiter works very well with low distortion and very good transparency. However, take warning: as with any wireless, properly setting the transmitter level is critical to the whole system sounding good. This goes for setting too high or too low! The transmitter’s level setting is independent from the main levels set between the receiver and your mixer. You set the transmitter level first, then the receiving end. Don’t use the transmitter as the system volume control.

The transmitters also have an adjustable, 18 dB per octave LF rolloff ranging from 35 Hz to 150 Hz. This is relative to the mic you happen to be using and is a helpful thing to have at this point in the chain of transmission. Good battery life: five hours on alkalines for the transmitters and similar for the receivers.

In Use

As they have a patent pending for the actual design of this Digital Hybrid technology, the specifics are not easily forthcoming but, as an end user, my interest is more focused on actual results rather than debating how many angels are on the head of a pin so I begin with: How does it sound?

Well, damn good. Full bodied and neutral, and certainly different than any Lectrosonics product I have listened to in the past. I listened to Sanken CS3, Schoeps MK 41, Neumann 81 and 82 microphones as well as Sanken, Sonotrim and Countryman lavaliers. I used these under the duress of actual production in both noisy and quiet environments. The sense of constriction in the upper midrange that I had formerly associated with Lectrosonics was gone, replaced by a definite transparency that, for me, represents the sound of a hard-wired mic. Of course, the elimination of compander technology from the transmission chain is a large part of this, not to mention getting rid of pumping and breathing. Also, the absence of pre-emphasis/de-emphasis shows how good the signal to noise ratio has gotten. Another contributing factor is something called Smart Noise Reduction. This algorithm has three settings of Off, Normal and Full and seems to be quite a bit more than a fancy low-pass filter. It is aimed at mic noise or hiss with minimal impact on important high frequency elements like sibilance and voice tones and is quite effective.

How was the RF? Well, I have always had a bias towards “true diversity” in UHF transmission, which means two real receivers. But I experienced a phenomenal display of Lectrosonics capabilities while shooting a Paramount project at the defunct Sybil Brand Women’s Prison in Los Angeles. With only the flexible rubber duck antennae on the receiver, Adam Blantz, one of my friends and boom operators, walked his stick with a Sanken CS3 mic up three storeys above me in a prison cell block of concrete and steel before I experienced an audible wireless hit. We performed further walk tests with the system and consistently were able to achieve distances of 1,000 to 1,200 feet with or without obstructions and without any fancy antenna system enhancements. Before this, I had experienced this kind of range consistency with only one other manufacturer’s product. Again, this is very impressive.

The build quality is also terrific and considering the types of transmitters available, presents a very unified systems approach to building a wireless package for motion picture work. In addition to the primary UM400 ($1,250) beltpack transmitter, Lectrosonics offers several other important designs: the UH400 ($1,090) plug-on transmitter is an excellent update of a venerable design as it is the DSP version of a phantom powered transmitter for boom or handheld use, the UT400 versions of dedicated hand held mics and the very sexy MM400A miniature transmitter. The MM400A is a watertight housing with a super hard Teflon nickel finish almost half the size of the standard transmitter. I wish I had these on Titanic instead of the bulky waterproof bags I was limited to. My only complaint about these waterproof gems is the choice of a 2.5mm subminiature connector. Although it provides very effective waterproofing, it limits you to a two-wire connection, albeit minor in the scheme of things.

All great stuff and it gets better, these receivers have a Frequency Scan Mode, which is a spectrum analyzer. You can scan within your 25 MHz spread to find the holes! There is a graphic representation as you scan your band and you just stop the scanner when you get to a space that is in the clear. The display then zooms in to a more detailed view, you choose the clear spot and the receiver then tells you what switch positions to set on your transmitter, all in a matter of a few seconds. This is very effective technology.

This is all very nice, but on top of this comes something I consider terrific. Because of the DSP design, this equipment is capable of full backwards and forward compatibility or more accurately, emulation. Both the transmitters and the receivers have user selectable menus for emulating most of the UHF historical product line Lectrosonics has produced all the way back to the 190 series. This means that you don’t have to make your package a pastiche of obsolete items. Everything is cross-compatible and more interesting is the compatibility with other manufacturers’ transmitters and receivers. A very cool thing if your talent has favorite mics for handheld performance work or more cool if you want to unify your receiving systems without having to purchase all new transmitters at one time. This concept will be dramatically enhanced by late spring/early summer of this year as Lectrosonics is planning to release their new line of Venue receiver systems which will allow you to have up to six 4llA style receivers in one single rack space unit for a substantial reduction of the cost of current receiving systems without sacrificing quality. I will be doing a full review of the Venues when they become available.


These are very serious tools for sound work, great sounding, excellent RF capabilities, built brick house tough, priced fairly, all from a company open to contact from any end user who wants to participate in the process of their ongoing evolution. The documentation is also very well done and is available as PDFs on the Lectrosonics website: