REPLACING the Bose X with a headset that actually is better, rather than just a bit of marketing fluff, must have been a difficult task for the US company.
After all, the X has been lauded by pilots all over the world and is usually found hard-wired into many top of the range aircraft such as the Cirrus SR22 and Cessna Columbus.
But according to Bose, it was determined not just to add new features which many pilots had been asking for, but it also wanted to improve the acoustic performance.
There were chinks in the X's armoury, small chinks admittedly, but that's what Bose had worked to over come with the Bose A20.
First up let's talk about the primary function of any headset - the sound. I've been using the Bose A20 headset flying a Diamond DA40'S at Shoreham, while doing some recurrency training.
R/T in this part of the busy south-east is essential and often fast - moving. Shoreham itself is pretty busy and if you've ever tried talking to Farnborough Radar, well you'll know that's a real jamboree.
Using the A20 was a real delight. The clarity of the messages coming in was the best I've ever heard, and my returning calls seemed to be understood ok.
The sound quality of the A20 headsets is astonishing, it really does strip out all the unnecessary sound leaving just the voice you want to hear. In fact, it even seems to enhance the quality of the incoming voice transmission to improve clarity.
That's a real bonus when the worldoad's high, such as when calculating a new heading and ETA for a diversion, while also keeping an ear out for your call sign. And yes, that exact scenario did happen.
Despite being on a 'Basic' service with Farnborough. they still called to pointout traffic closing in on our left, requiring an acknowledgement.
The ANR doesn't completely remove all outside noise, but it's reduced to a minute level of being 'just there'. So if the DA40's engine was to quit, I'd probably be aware of the lack of sound as well as the missing underlying vibration.
I didn't try switching off the engine in flight to check, sorry. The quietness induced by the Bose A20's ANR is something to be marvelled at. particularly if your aircraft has a noisy cabin, as many composite construction aircraft have.
Bose says it has uprated the ANR by having microphones both inside and outside the ear cup to more effectively detect, measure and react to cockpit noise, thus creating a more precise noise cancelling signal. New electronics achieve and this and can cope with higher noise levels than before.
That's with the ANR switched on. It does have to be manually switched on, even if you have taxen ine option or naro-wiring the headsets into your aircraft's intercom. It switches itself off after 3-9 minutes in inactivity, says Bose. and I can confirm that.
Useful - if you forget to switch off and pack the headset away in your bag, it means the batteries won't be flat next time. With the ANR off, the sound quality is ok and there's a definite improvement in the 'passive' noise reduction.
This is down to the new ear cushions, says Bose. They're plump and lush, very tactile, and finished in a very soft leather. However, once you've tried the ANR, you won't go back - the difference is outstanding.
The new ear cushions contribute hugely to the A20's overall comfort level. The new bigger ear cups/cushions seem to embrace the ears with just the right amount of pressure, claimed to be one-third of the pressure of other leading headsets. The new headband is a very clean redesign of the X, though the family resemblance is kept and it sits on the head so lightly you forget it's there.
The headband is lighter with easily adjustable extensions and simple swivel joints on the ear cups. The company says the weight-saving on the headband balances the extra weight of the new technology in the ear cups. The A20 weighs 340gm, exactly the same as the X. You'd never notice the weight redistribution - it just works.
The new control unit, makes it hard to accidently change the volume levels.
Materials used in the A20's construction are stylish and high quality, as you'd expect in a $900+ headset. Strong, quality plastics with precise shutlines and chamfered edges. The outer side of the ear cups looks very modem and neat, with two exterior microphones recessed into each cup. The only slight naff touch are a small clamp held by two crosshead screws in each ear cup swivel - they're hidden from outside view so barely noticeable.
So, importantly, the A20 is a major step forward from the X in its primary function and comfort. But what's also happened is that Bose has listened to pilots about what the few glitches the Bose X had, and also to what extra features they'd like.
One important change is to the control unit. It too has been redesigned, not only to incorporate new features, but the old exposed volume controls are now set within a plastic surround - so the volume isn't accidentally changed. The ANR is switched on by pressing the power button.
You can either use the A20 powered by 2 AA batteries, said to last 45 hours, or if they are hard-wired in the aircraft. Below the power button is another LED and another button - these are for the Bluetooth connectivity.
It can pair with a mobile phone to make or take a call. The process is simple and the headset paired with an iPhone in seconds. We made a call while on the ground to test the system and it worked perfectly.
Even in a very noisy cockpit, the passive noise reduction is excellent on the Bose A20 hedset.
At the base of the hand unit is an auxiliary input socket for an external audio source, such as an iPod or handheld GPS. Also on the hand unit is a three-position switch which allows the pilot(s) to choose who hears what.
In the 'Mixed' setting, an incoming R/T call can be heard along witn an external audio input, in 'Prioritised, the external source is muted when there's an incoming call. The third position is 'Off', removing the external source completely. This means that you can set, say, four headsets to different responses.
The pilot(s) will want 'Prioritised' while passengers can continue with the 'Mixed' setting. Various options are available. Without Bluetooth, the price drops to around $835. It can be had with the standard GA plugs or the six-pin connector for hard-wiring. And a helicopter version will be available soon.
THE story of Bose goes back to 1956 when Dr Amir Bose graduated from the Massachusetts Institute of Technology, bought a stereo and was disappointed with the quality of the sound, so after a period of intensive research into the behaviour of sound, he created his first product, a speaker.
In 1964 he created the Bose Corporation. There's a similar tale behind the Active-Noise Reduction (ANR) technology that underpins both the Bose X and A20 headsets. Dr Bose was on a flight in 1978 and was offered the in-flight electronic headphones.
Again, he was disappointed with the result, finding that noise intruded and if you turned up the volume it distorted the sound.
On that flight, he decided the answer was to cut out background noise and he started development immediately.
Various prototypes using ANR were built and in 1986 Dick Rutan and Jeana Yeager used a set for their successful Voyager non-stop round-the-world flight.
By 1989 Bose had the first commercially available ANR headset available for light aircraft and helicopters.
This was followed in 1995 with the Series II, awarded Product of the Year by AOPA, and in 1998, the Bose X followed which has set the standard by which all other headsets are measured.
TWELVE years is a long time in aviation (to be honest, its a long time in any business), but that's how long its been since Bose last launched a headset. Once again, the company has raised the bar in terms of ANR headsets with its new A20.
The main differences are to the ear cups and control module, plus the ability to use Bluetooth, the addition of a 3.5mm auxiliary audio input (MP3 player, GPS unit etc) and priority audio switch: things the Bose X lacked.
Bose claims the noise reduction has been greatly improved as a result of the engineers putting microphones inside and outside the earcup to more effectively measure, sense and react to noise changes.
"Although we haven't measured the noise reduction between the A20 and the X, there is noticeable difference between the two units," said Matt Ruwe, Bose's product marketing manager. "And although its not any lighter than the X, our designers have repositioned the weight so it feels lighter while being worn".
The control box has seen a drastic change. The volume control has moved from the side of the module to the centre to try to reduce accidently changing the volume when moving around the cockpit.
The auxiliary input jack has been placed at the bottom of the control module so the wire from the MP3 player will flow parallel to the modules wire.
The mixed audio setting means the pilot can hear the aircraft radio as well as the auxiliary input signal, and there is a prioritised audio setting, so the auxiliary sound will be muted during transmission of important radio communications.
Bose claims two normal alkaline AA batteries will last for up to 45 hours in the A20.
Ear pads with extra soft leatherette cover and viscoelastic filing
Automatic volume reduction of phone or music player when signals from the Intercom occur (selectable function)
Mono/stereo selection switch
Noise-compensated microphone with adjustable gain
Integrated volume control
Rugged headband design made of sonng spring steel with soft, replaceable headband pad
Modular construction for easy servicing
Weight 325g (without cable)
Wind shield for miaopnone
Connecting cables for mobile phones (including iPhone)
Connecting cable for portable music players such as CD or MP3 players
COURTESY: LOOP magazine.