Many of us grew up with the name Shure—and its ubiquitous ball-end SM58 mic. Over the decades, the company has stayed true to its roots, and continued to develop wired and wireless microphones for a variety of applications. Shure offers wireless microphones with features and prices to suit applications ranging from entry-level to professional—including the just-introduced PGX Digital wireless system.
Wireless Frequency Band
The PGX Digital system operates in the 902-928 MHz spectrum, out of the range of DTV transmissions. Equipment used in this frequency band is unlicensed, and generally below one-watt output power. Since the band is above that of digital television and other strong radio signals, interference from those sources is not a problem.
The PGX Digital system
This new digital wireless system consists of a handheld or body pack transmitter and a stand-alone receiver. The hand-held features either an SM58 or Beta 58 mic, and uses Shure's screw-on interchangeable head. The body pack has a four-pin TA4M connector, which mates to either lavalier microphones or an instrument cable.
The receiver is compact and utilitarian. Antennas and controls are on the front, with connectors on the rear. It is powered with an external in-line 120-V adapter that provides 12 feet of flexibility in positioning the receiver, along with the convenience of a two-pronged AC plug.
According to the specifications, line-of-sight working range is 200 feet (60 meters) with a frequency response of 20- 20,000 Hz. The audio sampling is 24-bit at 48 kHz. Transmitter RF output power is 10 mW, over a 500 kHz bandwidth.
Handheld Microphone Transmitter
The PGXD24/SM58 system ($449 retail price) includes the PGXD2 transmitter with the SM58 mic head. Other heads, including the SM86 and PG58, are also available. The transmitter features a -10 dB pad switch, which is accessible when the head is removed, in case the current singer/presenter is overloading the first audio stage. The transmitter is fairly well balanced and solid, and also heavy at about 14 ounces including the two AA batteries.
A recessed on/mute/off switch is located just above the threaded cap that covers the battery compartment. Normal handling will not turn the transmitter on or off, yet it is easily pressed with the tip of a finger or thumb. A brief hold will turn it on, and a click will mute the mic with a second click to un-mute it. The LED indicator above the switch clearly shows status. The transmitter can also be locked on with the mute disabled by pressing the switch for five seconds.
The infrared (IR) port, which is used to synchronize frequencies with the receiver, is located at the base of the transmitter under the cap. Two alkaline AA batteries provide up to nine hours of operation.
The PGXD14 system ($429 retail price) includes the PGXD1 transmitter, which accepts lavalier mics or an instrument cable with a TA4F connector, with 26 dB of gain adjustment. A flexible wire whip antenna is top mounted, next to the recessed power button (same functions as the handheld). Two AA batteries provide up to 10 hours of operation.
The lower front section is hinged to access the battery compartment and the IR sync port. Two spring-loaded clips on either side hold the door firmly closed, although it takes a bit of practice and a precise grip to open it quickly and easily. The polycarbonate body pack is sturdy and slim, with a spring steel clip securely attached. The instrument cable is long enough to attach to a guitar strap or belt, but a bit more length would be useful to allow room for movement.
PGXD4 Receiver
The receiver is housed in a compact molded enclosure; two would fit on a rack tray, or they could be placed on consoles or shelves. A hinged, rotating quarter-wave antenna is mounted on each side of the front panel for adjustable positioning. The receiver turns on when the power supply is plugged in.
The simple front panel features a button to scan and select the best available channel, and another button for the IR sync with the transmitter. A two-numeral LED display shows the group and channel number. An RF indicator LED illuminates when its transmitter signal is detected, and doubles as a battery level indicator. The audio LED flashes green when an audio signal is present, and changes color when nearing clipping.
The rear panel has a balanced male XLR connector and a female quarter-inch connector, along with the power input. Gain adjustments are done at the mixing console.
System Setup
The PGX Digital wireless is relatively simple to set up and operate. Connect power to the receiver, push the “channel” button to scan available frequencies, and have the unit select one. Power up a transmitter, expose its IR port to the receiver, and push the round IR button until the LED flashes. Now they are sync'd and ready to work together. For additional receivers, repeat the procedure while leaving the previous transmitters on. Press and hold the channel button to manually scroll through available frequencies and select one.
The system contains several predetermined groups of compatible frequencies, so the frequency coordination is already accomplished. Groups seven through nine will allow five PGX Digital systems to work together.
Testing the PGX Digital System
The test system consisted of a handheld transmitter with an SM58 head, a bodypack with an instrument cable, and the receiver. The initial audio tests were positive, with results similar to a wired microphone, and the guitar sounds clean and accurate with both acoustic and electric guitars. The transmitters powered on with a slight “whooshing” sound, but no pop, while muting and un-muting was accurate and silent. Turning the transmitter off only caused a tiny pop, even at high gain.
Walk-testing the system, I was able to reach at least 200 feet before I heard some brief dropouts in the audio (via a digital recorder at the sound system). The audio would be gone and then reappear, but without much noticeable noise. As I got beyond range, the audio stuttered on and off, and then the system stayed silent.
At the local performing arts center we tested the PGX Digital vs. wired mics and the engineer's more expensive Shure UHF-R wireless. He also had Beta 58 and KSM9 mic heads, which we placed on the PGXD2 handheld transmitter to see how it handled them. The audio quality compared admirably with wired mics and the higher end analog system—sounding quite similar through the main system and through headphones.
With acoustic guitar through both a PGXD1 and UHF-R bodyback, the PGXD1 was clean and full-range, although the guitar sounded a bit “warmer” with the higher end UHF-R body pack. We did notice in the walk test that the noise from a dropout was louder than with the solo test—most likely because we had the receiver sitting near other wireless and digital signal processing units. The overall impression is that the audio quality through the PGX Digital wireless is quite good, and that the sampling, digital transmission, and decoding are accurate—especially when the modest price point is considered.
Conclusion
The PGX Digital wireless system is easy to set up and use, and provides very good audio response with a resistance to extraneous noises because of its digital transmission. Its range is less than some analog units with higher transmitter output, although fine for most applications. As a moderately priced system, the controls and amenities of the receiver are nothing fancy, but they get the job done. If If you need to add a few channels of wireless to a new or existing facility, consider the Shure PGX Digital.
