Sound technology has remained largely unchanged since the 1930s, but now there is a technology that revolutionises the way you listen to audio.
Welcome to airSOUND™.
IN THE BEGINNING THERE WAS
Played through a single channel providing no sound perspective and no width.
THEN THERE WAS
Played through two channels, but requires the listener to be in a specific location to hear the full sound definition.
NOW THERE IS
Hear the full sound definition from anywhere in the room, all from a single unit.
airSOUND™ does not require the listener to be in a specific location to hear the high definition details in the sound being reproduced. airSOUND is a point source system, so there are no problems caused by similar sounds coming from speakers that are a distance apart (Stereo e.g. can only deliver HD audio to listeners located in the 'sweet spot'). With airSOUND, you can enjoy truly HD audio, no matter where you are in the room.
There's nothing more frustrating than not being able to hear what is being said on a TV programme or film. With airSOUND™, you'll never miss a word. The enhanced dialogue clarity is due to voices coming from a single, centrally located loudspeaker. This is the main advantage of 5.1 systems, but without any of the associated clutter.
With airSOUND™, you don't need more than one unit to hear audio how it was intended to be heard. Simply plug in and enjoy. airSOUND delivers a true wide soundscape from a single box. (Please note, some units use a separate subwoofer for enhanced bass, but these can be placed out of sight).
airSOUND™ was invented and developed in Britain (in Ted Fletcher's studio in Devon, England). We use airSOUND™ in all of our products; that are all designed in the UK. Read more about the airSOUND story
Even when listening from one side, the left and right audio channels are perfectly balanced. airSOUND™ achieves this with it's unique approach to creating spatial audio. This is not the case for Stereo, where the left and right channels are played by left and right speakers. When listening from one side, the closer channel will dominate the farther one.
airSOUND™ delivers the majority of the sound you hear from a point source. The sound dispersal is more efficient and smoother than stereo or multi channel systems. Other systems use separate speakers to produce similar sounds. The signals interfere with each other in the air, causing distortion, and loss of audio energy.
To understand what airSOUND does, let's look at how we hear sound from stereo speakers:
A traditional ‘stereo’ system has 2 speakers, placed a distance apart. These play the left and right channels of recorded sound, intended for the Listener’s left and right ears separately. The Listener must be in between them, in the ‘sweet spot’ to hear a good sound. If the listener is closer to one speaker than the other, then the stereo effect is lost.
For portable speakers or soundbars where the left and right speakers are close together, the left and right channels cannot be heard separately, so there is very little stereo effect.
airSOUND works differently. The sound that is intended for both ears comes from the front. Side speakers produce only the spatial information, and do not need to be heard independently by left and right ears, so, a Listener will hear a complete stereo image from the front and either of the side speakers. This is how airSOUND overcomes that fundamental limitation of 2 speaker stereo, allowing true freedom from the stereo sweetspot.
When in the ‘sweetspot’, that is, equally distant from the left and right speakers, the Listener hears good separation of the left and right channels (left channel to only the left ear, right channel to right ear). The separation of channels and good balance means the stereo image the Listener hears is good. When the Listener moves outside this area, then several things happen. Firstly, the closer speaker will sound louder, and be heard by both ears dominating the farther channel. In addition, the increased distance of the far channel introduces a time delay since the sound has to travel farther. The listener hears ‘spatial distortion’ because of this delay in the farther signal interfering with the louder, nearer signal. (See the advanced section for more detail of this effect)
For smaller systems like portable speakers or soundbars, the speakers are closer together, but still several cm apart in order to create a minor stereo effect. The smaller distance between the drivers means there is no significant difference in perceived volume when heard away from the sweet spot, but the distance is enough to cause spatial distortion in the critical midrange and upper frequency bands, essential for hearing clear speech or detail.
The airSOUND system does not suffer from these balance and timing problems because all the speakers are located close together, with all the detailed sounds coming from a single point on the front. When the Listener moves around the listening space, there are no conflicting secondary sound sources to cause any spatial distortions as described above. Note, the side speakers are not replicating any of the sounds coming from the front. On it’s own, the front speaker would not be able to convey a stereo sound. It is the job of the side speakers to produce sound that works independently of the front to produce the stereo image. The Listener hears perfectly balanced and distortion free stereo sound, everywhere due to the interaction of the front and side channels from any listening location.
Consequently, Listeners hear the left and right channels in perfect balance, well separated, and free from spatial distortion at all listening locations.
Note: Please read the intermediate explanation first.
(portable speaker or soundbar)
Considering a portable speaker or smaller stereo device, we can put some numbers to the issue of speaker distance and time. If a Listener is off-axis by 45 degrees (the off axis Listener, pictured above), one loudspeaker could be 10cm farther away than the nearer speaker. In this case sound has to travel 10cm further to the listener. Sound travels at 340m/s, so it takes the sound only 0.0003 seconds to travel this far. However, if we consider a mono signal containing a frequency at 1700Hz (the wavelength of which is 20cm), this sound would be greatly cancelled out by the farther speaker from the off axis listening position. This is because from where the listener is, as the sound from the far speaker will be exactly 180 degrees out of phase relative to the sound from the near speaker when it arrives, and largely cancel out, resulting in a strong dip in frequency response at that location, at that frequency. This cancellation is not consistent either, as the frequency rises higher, the cancellation will get less till we hit 3400Hz.
At this point, the distance of the second speaker is exactly 1 whole wavelength away, so this fundamental frequency will multiply resulting in a peak in perceived volume. As the frequency runs higher, we swing towards cancellation, and so on. Changing the distance between the speakers (or listening position) will change the point at which cancellations and boosts occur. This effect can be thought of as ‘spatial distortion’. Sounds such as the human voice are complex, the sum of a colossal (even infinite) number of fundamental frequencies in this band. This effect distorts such sounds across the midrange chaotically, resulting in intelligibility loss, and a harder listening experience. In real life, this effect can be heard as ‘phasing’ as the listener moves around the loudspeaker. It’s unnatural and it is one of the most striking improvements of a single speaker or airSOUND system over a small stereo setup for listening to speech (e.g. talk radio).
For larger 2 speaker stereo systems the effect is less noticeable as the distance between the speakers is so much larger, the nearer speaker is perceived at a higher volume than the further speaker, masking the delay / spatial distortion effect. But, the Listener hears mainly only the near speaker, so there is no stereo effect either.
Apart from the problems of distortion, remember that to hear 'stereo' the Listener needs to hear both channels at equal volume, by both Left and Right ears, and so neither a system with separated speakers or with speakers close together can achieve a stereo image with the Listener 'off axis' which is what airSOUND delivers.
airSOUND is an audio process combined with a different placement of speakers. The internal audio process is to turn a stereo signal (Left and Right), into what we call ‘Main’ and ‘Spatial’ signals. Essentially, the Main signal is the sound that both ears should hear. The Spatial signal is a sound that makes the ears respond differently to one another, and so in combination with the Main signal, conveys a full stereo image when the Listener hears it. The sounds are played independently, and recombine to form stereo in the air, hence the name, ‘airSOUND’.
The majority of sound (and, certainly all the sounds that convey the detail in what the Listener hears), should be heard by both ears. The airSOUND process ensures that these sounds are produced from a single (point) source. This completely eliminates the spatial distortion referred to above. From any point, speech e.g. remains perfectly clear and undistorted. airSOUND speakers will often feature multiple drivers on the front face. In this case, crossovers are used to ensure that all the higher frequencies come from fewer radiating surfaces than lower frequencies in order to absolutely minimise any spatial distortion off-axis. In this way, the Listener can be off-axis, yet will not experience distortions from similar sounds coming from multiple sources.
The side speakers produce a signal that makes the Listener’s ears respond differently to one another. This is independent of the front signal, so there are no effects of spatial distortion of the main signal as described before. To work, the side speakers rely on the increased directionality of shorter wavelengths in the midrange and upwards for sounds that give Listeners cues as to the direction of audio. For such frequencies, if a sound approaches the listener from the side, then the Listener’s ears will react with different ‘phase’ or timing of each other due to the direction the ears are pointing, and the time taken for the sound to travel the additional distance to the farther ear. The side speakers are able to affect the Listener’s ears equally throughout the listening environment, so all Listeners perceive the same spatial ‘polariasation’ from anywhere, irrespective of which side speaker is closer. This sound mixes with the main signal at the point where it is heard to become a fully stereo signal; at all points in the listening space.