Lectrosonics, a staple in professional broadcast and TV production with a significant presence in live theatre andconcert/touring, recently released its fourth-generation fully digital wireless system the “D-Squared.” Not a newcomer to wireless microphones, the company has almost 50 years of experience designing and building wireless in its New Mexico manufacturing facility. In this latest system, with its exceptional features, specifications, and sound, all that experience comes to play.
To start with, both receivers and transmitters cover the entire legal U.S. UHF spectrum, so you don’t need to decide which frequency range will remain clear in your area. Since each half-rack receiver houses four channels, you can likely outfit your whole worship team in one rack space. And though D-Squared is a significant investment in truly professional equipment, you’ll be able to check upgrades or wireless problems off the list for many years.
The D-Squared Digital Wireless System is extremely well-built, highly durable, and offers virtually all of the capabilities you’ll need for pristine, reliable wireless audio performance over many years.
While it’s a sophisticated system, D-Squared provides similar and compatible controls and functions for the receiver and transmitters, so with a few minutes of familiarization one can begin working through the settings and menus. Use a single receiver stand-alone if you need just a handful of high-performance wireless channels, or link several together with shared remote antennas and Dante digital audio networking (or optional AES3), andcontrol in real time via networked Wireless Designer software.
The receiver works with the DHu handheld, DPR plug-on, and DBu bodypack transmitters, and is also backwards-compatible with the company’s Digital Hybrid transmitters.For wireless communications where redundancy could be important, such as filming a service where the preacher is sermonizing while walking the aisles, you can link receiver channels and use two transmitters to mic the same source—using the frequency diversity method. When necessary, you can add AES 256-bit encryption with three levels of selectable security. Let’s explore the details.
A box of surprises
My first surprise when I opened the box was how small the dBu bodypack transmitter was, fitting easily in the palm of my hand. Then I picked it up, and discovered how dense and sturdy it felt, and its build quality. In this world of disposable electronics, the bodypack was built to last.
The handheld transmitter was as sturdily built, and when I opened the handle to insert the batteries, it slid smoothly yet firmly to expose the controls—like a finely designed tool.
I also want to call out the packaging as the most environmentally friendly I’ve ever seen—durable and with all the necessary information printed on it, without any flashy marketing. Instead of Styrofoam blocks with cutouts to house the electronics and accessories, everything was securely held in place by ingeniously folded cardboard faced with a tough, thin layer of clear flexible plastic that held the contents in place. With this method nothing could move or be damaged in shipping, yet the box held mainly air. Virtually all of the packaging is recyclable.
RF matters
The D-Squared wireless system is a quite sophisticated radio, offering a variety of options for achieving excellent wireless audio even in difficult and critical situations. It uses a high data rate digital transmission between the transmitters and receivers to provide transparent, full-range audio signals, and to my ears the end result sounds very natural and noiseless.
The DSQD receiver can perform a frequency scan of the entire covered spectrum so you can find which areas are clearer or already contain other radio signals, using each of the four receivers to scan a portion of the spectrum for greater speed and efficiency. Both the receivers and transmitters cover the entire legal U.S. UHF band between 470-608 MHz (up to 614 MHz for systems sold outside the U.S.).The true-diversity receiver features a pair of independent receiver circuits for the A and B antenna ports, and when set to Switching mode will select the signal from the circuit receiving the best signal—switching at the packet header to ensure seamless audio.
For even greater security with critical communications in difficult RF conditions, additional diversity methods can be selected via the menu, joining two receiver channels into one or even using a pair of transmitters for redundancy. Ratio diversity uses the signals from one transmitter, picked up by antennas A and B, and blends them proportionally based on signal integrity to maintain the highest signal level and best audio. For full redundancy, frequency diversity uses two transmitters set to different frequencies, and selects the output of the transmitter with the best signal at the receiver.
You can tune each device in 25 kHz steps, using a coarse/fine-tuning method for greater efficiency to select an exact desired frequency—and either set both transmitter and receiver manually to the same frequency or use bi-directional IR to rapidly coordinate the frequency on the receiver channel with a transmitter during setup. I played with this process, and it works nicely with the respective IR windows in close proximity. You can also set up coordinated frequency groups, and assign the frequencies from the receiver channels to the transmitters.
Transmitter power is selectable, at 25 or 50 mW, and with a shorter push of the power button the transmitter will turn on yet disable the RF transmission so that you can change settings and frequencies without potentially transmitting an unwanted signal to interfere with an ongoing event.
The DSQD receiver is also backwards-compatible with the existing Lectrosonics Digital Hybrid and Duet transmitters. Audio latency is extremely low, at 1.25 ms via the analog XLR output, and under a millisecond to the Dante digital output.
The DSQD Receiver
Many of the more recent high-end wireless receivers have enclosed several receiver channels in a single chassis so that certain aspects, such as the antennas/multicoupler, audio circuitry, networking, control surfaces and menus, and the enclosure itself, can be shared. The result is much greater channel density in your wireless rack. Even though this can be more expensive for those needing only a couple channels of wireless, there are benefits for moderate and larger wireless requirements.
For example, since each half-rack DSQD receiver contains four channels, two rack spaces could hold 16 channels of professional-quality wireless, and be fed by one pair of remote antennas by using the antenna loop-through jacks to connect all the receivers. Similarly, they could all be connected through the Dante ports to a digital audio network (or use the individual XLR connectors for analog audio) and the network ports for computer monitoring and control.
"Both receivers and transmitters cover the entire legal U.S. UHF spectrum, so you don’t need to decide which frequency range will remain clear in your area."
The receiver itself is well laid-out, with a full-color LCD display surrounded by navigation and control buttons, for Menu/Select, Back, up and down arrow keys, and four buttons below the screen corresponding to the individual channels so that each can be selected for further detailed settings. A headphone jack with level control, power switch, USB port, and IR linking window complete the front panel. On the back, four balanced XLR audio connectors reside with Dante digital audio ports, Ethernet for networking, antenna input plus linking connectors, and a locking power input for the external power supply. Another pair of connectors are reserved to link multiple receivers so that the entire system can intercommunicate and perform frequency coordination offline (“coming soon”).
Once I played with the controls a bit, I found it relatively straightforward to navigate the menus, adjust channel audio levels, link channels, change frequencies and send the change via IR to a transmitter, perform a frequency scan, name channels, and other normal functions. I liked how the receiver display shows basic information for each channel, including a scrolling RF meter that horizontally shows the last 10 seconds of that channel’s RF history—and with a touch of the channel select button I can use the entire screen for a more detailed channel view and access to settings. The display is clear and bright enough to be legible outside in sunlight, and can be dimmed or timed out for darker environments. In addition to the battery level meters, you can even set alerts to remind you when it’s time to change individual transmitter batteries.
DHu Handheld
TransmitterThe handheld transmitter is a substantial, well-balanced instrument that is comfortable in the hand and not overly heavy given its made-to-last construction. The machined aluminum chassis fits together precisely, having the appearance of an integrated unit that fully protects the controls and electronics it houses. Yet it very smoothly unscrews in a couple of seconds to reveal the control buttons.
"Since each half-rack receiver houses four channels, you can likely outfit your whole worship team in one rack space."
The six buttons include power, Menu/Select, up and down arrow keys, a Back button, and a final one to program a small external button located on the chassis just below the microphone head. That low-profile button can be programmed to give the user the ability to mute and unmute the audio, momentarily press and hold it to suppress a cough or other unwanted sound, set to push-to-talk, create a talkback communication channel, use it to turn the transmitter on and off, or leave the button disabled. The layout of the buttons is quite accessible and easy to work, and can also be seen in low light conditions for quick behind-the-scenes adjustments. The transmitter is powered by two AA batteries, which fit tightly to prevent any rattling or loss of contact. A clever “battery eject” lever pops them out when you need a fresh pair. Within the transmitter menu, you can select whether alkaline or lithium batteries are being used, so that the battery life is more accurately measured. Per the specs, battery life is five hours using Duracell Quantum alkalines, at the 50 mW output power setting.
Mic capsules are easily interchangeable so you can use your favorite mic brand, or the standard Lectrosonics cardioid condenser head (there is also an optional variation that integrates a preamp / EQ). Gain can be adjusted in 1 dB increments over a range of 45 dB, with a pair of LEDs to help guide the process – plus a selectable roll-off at 35, 50, or 70 Hz. Transmitter frequency response is 40 Hz to 20 kHz, +/-1 dB.
DBu Compact Bodypack Transmitter
As I mentioned, the digital bodypack is quite compact, measuring about 2.5 inches by 2.75 inches with a depth of ¾-inch (minus the detachable whip antenna and belt clip). However, it has a solid heft, and its rugged machined aluminum chassis ensures that the bodypack will withstand heavy professional use. Even the battery door is metal, with a durable spring hinge that is not difficult to open and closes and latches securely. The same buttons as on the handheld make their appearance on this transmitter’s front face, framing the display—along with a pair of status LEDs. The top panel has a pair of input level LEDs, a five-pin TA5 connector for mics or instrument cables, the IR linking window, a recessed programmable switch, and an antenna port. Since the system covers such a wide radio spectrum, two interchangeable antennas are provided to cover the lower and higher portions of the range most efficiently. The programmable switch can be set for mute, power, talkback, or disabled.
Like the handheld, the bodypack is powered by two AA batteries, and has a selectable RF output of 25 or 50 mW, with a battery life of five hours. Since it can be used with a variety of input devices, from headsets to lavaliers to instrument pickups to line-level signals, the bodypack has a gain control range of 44 dB in 1 dB increments. In addition, since the bodypack is designed to work with such a wide variety of input types, from bass instruments to voices, roll-offs can be set at 20, 35, 50, 70, 100, 120, and 150 Hz. Frequency response is 20 Hz to 20 kHz, +/-3 dB.
Walking with D-Squared
I find it useful to walk an area where wireless will be used, to see if there are any places where the RF signal drops too low to reproduce audio, and to check out the maximum range. A walk-through will also help determine the best position for remote antennas, if used. In my tests, I used only the whip antennas on the receiver, and they were below the direct line-of-sight of the transmitters as I walked, with a couple of walls in between.
With the handheld transmitter, I was able to have consistent audio at over 225 feet, with the transmitter’s output power set at 25 mW. The channel’s RF meter was showing green, and occasionally going into the yellow when the signal level decreased a bit. I expect that if the setup was line-of-sight, or if I was using external directional antennas, the maximum distance would show a significant increase—given a similar low ambient RF level as in my more rural location.
In another experiment, I used two bodypack transmitters at different frequencies and joined channels three and four for frequency diversity. The transmitter outputs were set to 50 mW, and they were placed on opposite sides of the body. The system maintained full, noise-free audio response without a dropout to about 300 feet, again with the same non-line-of-sight setup. I concur with the statement in their data sheet that the D-Squared has “an extended operating range rivaling the best analog systems.”
Making the decision
Lectrosonics’ D-Squared system is a high-performance, professional wireless—and like other top wireless microphones represents a serious investment that is not for every church or application.
It’s extremely well-built, highly durable, and offers virtually all of the capabilities you’ll need for pristine, reliable wireless audio performance over many years. And you can trust that the company will still be there when you need help, and when you need to expand the system.
Street price for the four-channel DSQD receiver is currently $4,990, and the DHu and DBu transmitters are $1,599. Doing a quick online survey of other wireless mic systems at a similar quality and performance level, I found that others’ per-channel pricing generally matched or exceeded the Lectrosonics system.
With the caveat that the audio quality your congregation hears begins with the microphone, if you have a high-quality audio system installed in the sanctuary, your services are broadcast via radio or television or online, or you regularly put on complex, multichannel productions, then the Lectrosonics D-Squared wireless system deserves some serious consideration.
