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AuraSonics DUET 20S2 DIGITAL — an affordable wireless system with two handheld transmitters

Maxim Liadov

AuraSonics is a brand of Audioproject, Russia's largest distributor of professional audio equipment. AuraSonics products are made to the company's specifications and under its specialists' supervision. Production takes place at major factories that also manufacture products for leading brands. AuraSonics offers a wide range of audio equipment and accessories. The brand has been on the market for many years and focuses on popular, affordable products.

The new AuraSonics DUET 20S2 DIGITAL wireless system replaces the earlier DUET 20S1/S2 models. The DIGITAL label in the name makes the new model easy to identify. The changes include a choice of 8 channels and advanced digital technology called π/4 Differential Quadrature Phase-Shift Keying, or π/4-DQPSK. In simple terms, this provides better communication in a narrower radio-frequency band, making a free radio channel easier to find. The two antennas also provide diversity reception: the receiver always selects the stronger antenna signal. This reduces the effect of transmitter orientation and increases the reliable operating range.

DUET means that the package contains two handheld wireless microphones. This allows many uses, from karaoke and celebrations at home to presentations and events where one microphone is needed for the presenter and another for questions from the audience.

Specifications

  • Operating frequency range: 650.2–691.6 MHz
  • 8 fixed frequencies
  • Frequency stabilization: crystal-controlled PLL
  • Digital signal transmission: π/4-DQPSK modulation
  • Dynamic range: >90 dB
  • Total harmonic distortion: <0.4%
  • Output signal: 500 mV

Receiver

  • Reception: digital diversity with 2 antennas
  • Power supply: 12 V DC, 500 mA
  • Power consumption: <4 W
  • Signal-to-noise ratio: >95 dB
  • Image rejection: >80 dB
  • Sensitivity: -95 dB
  • Pre-emphasis: 75 µs
  • Frequency range: 20 Hz–20 kHz

Transmitter

  • Microphone capsule: dynamic
  • Polar pattern: cardioid
  • Frequency range: 40 Hz–15 kHz ±3 dB
  • RF output power: 30 mW
  • Modulation type: FM
  • Deviation: ±26 kHz
  • Power supply: 2 × 1.5 V AA batteries
  • Operating time: 5 hours

Official website: aurasonics.ru

As the specifications show, the AuraSonics DUET 20S2 DIGITAL offers 8 selectable channels, allowing more systems to be added. Up to 4 wireless systems, or 8 microphones, can work in the same room at once.

The microphones are paired with the receiver at the factory and can be used immediately after unpacking and switching on. A transmitter can also be paired manually by following the manufacturer's printed Russian instructions. Press the SET button inside the transmitter's battery compartment and the matching button for the required receiver channel.

The receiver's plastic housing keeps it light and compact. The fixed antennas are mounted at the front and rotate through 360 degrees.

The frequencies of all available channels are listed on the underside of the receiver. Rubber feet here stop the receiver from sliding across a surface.

The package includes two handheld transmitters. Each wireless microphone has a plastic housing and a metal grille. There are no flat sections or rubber rings to stop the microphone from rolling. A large display shows the channel number. The button switches the microphone on and selects MUTE mode.

Under the grille is a conventional dynamic capsule in the style of the classic SM58, with a cardioid polar pattern. A thin layer of foam inside provides extra protection against wind and breath noise. More expensive internal components improve the sound of the new handheld transmitters. This makes the microphones useful for more than home karaoke.

The receiver connects through analog balanced outputs. As usual, the XLR connectors carry the individual channel signals for connection to a mixer. The unbalanced 1/4-inch TRS MIX OUT combines both microphone signals and is useful for direct connection to powered loudspeakers. Analog volume controls adjust the output levels, partly replacing a mixer.

The handheld transmitter uses two AA batteries. As usual, the battery compartment is in the lower part of the microphone under a cover. The PAIR button is used for manual synchronization.

The model has large LED channel-number displays and is easy to operate. We tested the wireless system in different conditions and found no problems. Reception was stable, without delays or dropouts. We had no feedback problems when pointing the microphone at a loudspeaker. The handheld transmitters handle both singing and speech well. Changing the microphone's position in the hand produces little noise: capsule vibration isolation works well, matching much more expensive microphones.

To understand the sound character better, we tested the wireless system against a reference microphone. We connected the AuraSonics receiver to a mixer and compared it with the Shure BETA 58A, one of the best wired dynamic vocal microphones. This is an improved modern version of the classic SM58, with sensitivity increased by 3 dB. The DUET 20S2 DIGITAL capsules were clearly designed with the SM58 as a reference, because the overall sound is similar. A little more midrange and less bass on the mixer can bring the tone even closer. For speech, the difference becomes almost unnoticeable. This is a strong point in favor of AuraSonics, since the wired reference microphone costs twice as much as the entire wireless system under review. For singing, Shure still sounds better, but the gap is not huge. After years of developing dynamic capsules based on reference designs, major manufacturers have achieved good results even with affordable microphones. Overall, our tests show that the AuraSonics DUET 20S2 DIGITAL is suitable for a wide range of uses. The microphones respond well to EQ. Our recommendations can be a starting point for a more professional sound. There is nothing unusual or difficult about this. Using a mixer and its controls is normal with any microphone and a public address (PA) system. Live sound loudspeakers have their own tonal character, too. Much also depends on the conditions, including whether the system is used indoors or outdoors.

Conclusions

AuraSonics DUET 20S2 DIGITAL is a gradual development of the range. It adds digital transmission, channel selection, and improved wireless microphones. We welcome these changes. The system works well and suits many tasks, from simple home use to professional applications, especially on a limited budget. The option to add more channels by buying extra sets is another useful benefit.



Note. This is an adapted machine translation into English. It follows the “In simple terms” approach. Read the original article at https://prosound.ixbt.com/microphones/aurasonics-duet-20s2-digital.shtml.