The illustration above depicts Binaurally Encoded Beaming of Alerts, Alarms, and Voice Communications. Vivid positional rendering for enhanced situational awareness and intelligibility is achieved. Position and loudness of each source may be automated, or interactively positioned by the user by using our app.

Studies in psychoacoustics tell us that well-recorded stereo signals and binaural recordings contain cues that help create robust, detailed 3D auditory images. By focusing left and right channel signals on the appropriate ear, YARRA 3DX maintains key psychoacoustic cues and avoids crosstalk. Together, these cues are known as Head Related Transfer Functions (HRTF). Briefly stated, HRTF component cues are interaural time difference (ITD, the difference in arrival time of a sound between two locations), the interaural intensity difference (IID, the difference in intensity of a sound between two locations, sometimes called ILD), and interaural phase difference (IPD, the difference in the phase of a wave that reaches each ear, dependent on the frequency of the sound wave and the ITD). Once the brain has analyzed IPD, ITD, and ILD, the location of the sound source can be determined with relative accuracy.

YARRA 3DX works by delivering appropriate binaural signals to the listener’s left and right ears without the need for headphones.


Unlike surround speaker setups or traditional headphones, YARRA 3DX delivers accurate, high fidelity, 3D sound fields better than any previous technology. For the first time, an array of 12 – 33mm, independently amplified speakers — each with their corresponding DSP chip — creates a thoroughly convincing listening experience.
You’ll believe that you’re experiencing real life!

Basic Stereo Listening and Crosstalk

Figure 1 shows the diffusion of a traditional stereo system. The “target” listener receives signals from both speakers. However, stereo imaging is achieved by the proximity effect or “law of the first wave front”. In simple terms, we hear stereophonic sound because one channel of a stereo program is closer to one ear than the other.

For traditional music listening environments, this arrangement provides the largest possible listening area. However, the depth of the stereo imagery is diminished because some of the left channel leaks into the listener’s right ear and visa versa — this is called crosstalk.

The “target” listener hears signal from  both the left and the right speaker. Crosstalk can be removed by wearing headphones OR by carefully focusing the left and right sound beams to each ear.

Beamforming Binaural Sound

Figure 2 illustrates how stereo crosstalk is controlled in Yarra 3DX, using beamforming to control the directivity of the left and right channels, greatly diminishing crosstalk and allowing the brain of the listener to perceive a highly detailed stereo image with exceptional spatial dimensionality. The effect is quite similar in concept to polarized 3D glasses, where the observer’s eyes process two slightly differing images to produce stereo visual perception.

Headphones can reproduce 3D auditory images when playing binaural sources as well, but there are perceptual and practical drawbacks that make headphones undesirable or unusable in some contexts. Some companies are pitching headphones with multiple drivers for each ear, which will only the reduce the sense of immersive that users desire. Yarra 3DX removes the requirement for headphones and delivers binaural audio with greater realism.


We experience, immersive surround sound in 360 degrees — “binaural sound” — because we have two ears that filter and modify incoming sounds depending on where they originate. Our brains interpret these signals and determine the location of different sources thanks to something called and HRTF or Head Related Transfer Function.

A head-related transfer function (HRTF) defines how an ear localizes a sound in 3D space. As a source sound arrives at a listener, the size and shape of the head, ears, ear canal, density of the head, size and shape of nasal and oral cavities, modify the sound and affect how it is heard. Some frequencies are boosted and other are attenuated. The HRTF generally boosts frequencies in the upper mid range of human hearing (2 – 5 kHz). However, each individual has their own response curves making careful, individual measurements ideal for modelling 3D sound.
A pair of HRTFs (one for each ear) can be used to create a binaural sound that seems to come from a particular point in space. It is a transfer function, describing how a sound from a specific point will arrive at the ear. Some consumer headphones are designed to reproduce surround sound from binaural recordings using HRTFs. Some forms of HRTF-processing have also been included in computer software to simulate surround sound playback from loudspeakers.

Our heads have only two ears, but we can identify where sound come from in three dimensions – the distance, height information (above and below), in front and to the rear, as well as to either side. We have this ability because our brains, outer ears (pinna), and inner ear and  work together to calculate where a sound came from. Our ability to localize sound sources developed a very long time ago. Our ancestors needed this ability, since our eyes can only see a fraction of the world around a viewer, while the ability to localize a sound source works in all directions.

If a speaker system can reproduce the exact HRTF requirements for a listener, it is possible to convince your brain that you are hearing a 3D surround sound space.



Click on one of the sections below to read about the physical, electrical, and performance specifications of the YARRA 3DX.

General Description

The YARRA 3DX and accompanying subwoofer comprise a compact, programmable, internally amplified, line array loudspeaker in a minimal visual profile. The YARRA 3DX employs 12 – 33mm, full range dome drivers in a self-amplified, DSP-driven line array to project one or more customizable beams (channels) of audio. If oriented horizontally, each beam provides wide vertical and steerable narrow horizontal dispersion that is ideal for a wide range of applications including single and multi-player gaming, virtual and augmented reality experiences, home theater movie viewing (with stereo or surround soundtracks), hi-res audio music enjoyments, and special venue installations. YARRA 3DX is an ideal system for single or multiple language digital signage in public spaces, targeted announcement, limited dispersion music, private beaming, sound masking, etc. wherever highly articulated control of sound is essential.

• Low cost Beamforming/3D trans-aural speaker
• Simple to install and set-up
• Center Beam mode projects personal zone sound beam
• Ambient noise monitoring with automatic adjustment
• Self test mode to ensure all drivers are operational
• May replace headphones for immersive sound experience
• Slim profile with mounting points on back and sides of array
• Can project 360 sound including binaural, 5.1, & 7.1 encoded content
• Wall mountable

Electrical Specifications


  • Diameter 33 mm
  • Driver spacing 38 mm
  • Frequency Response 50 – 20,000 Hz (with supplied subwoofer)
  • Mean SPL 80 dB ± 3 dB
  • 98.2 dBA broad band steady state @ 1 Meter
  • 99.8 dBA peak…call it 100dBA @ 1 Meter
  • Max SPL deviation -1 dB
  • Impedance 8 ohms
  • Nominal input power per driver 2W, 4V
  • Max input power per driver 3W, 4.9V

Internal Amplification

  • Class D 4W x 12

DSP and Beamforming

  • Quad Core 500 MIPS
  • Internal EQ processing: 8 x 4 Band Parametric
  • Internal Beam Forming Modalities: Center, Stereo 3D Beam-forming; variable throw up to ~30 ft.
  • 160° V x 20° H max coverage per beam; up to 5 x 20° beams possible
  • Side lobe attenuations of at least 20dBA

Input/Output Connections

  • Line in analog 1/8” (3.5 mm) stereo
  • Mic in analog 1/8” (3.5 mm) mono
  • Line Out subout 1/8” mono

USB – B jack (audio or firmware upgrade)

  • DC power in 12 Volt
  • External control interface D-sub 9 pin

AC power

  • Condor Switch-Mode
  • Model: FJ-SW1203300
  • Input 100-240V~, 50-60Hz, 1.5A max
  • Output: 12V 3300mA


  • Self-amplified, line level analog input or USB digital input

Max power before distortion
On axis, binaural mode:

  • SPL white noise @ 1 meter – 104.8 dBA before distortion
  • SPL 1K sine @ 1 meter – 97 dBA before distortion

On axis, in center beam mode:

  • SPL white noise @ 1 meter – 107.3 dBA before distortion
  • SPL 1K sine @ 1 meter – 94.5 dB before distortion


  • V 1.0, upgradable in field via USB
  • GUI: PC based in-field programmable control of beam width, level, EQ, etc. via USB

Physical Specifications

The YARRA 3DX is designed to fit comfortably under a television or computer monitor. It has a low profile and features adjustable legs that allow monitor supports to extend under the unit. The array weighs 3 lbs.

Measurements & Plots