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Mobile Gadget News :: Making Your Mobile Life Simpler _ Accessory Review _ Review :: Logitech Mobile Freedom Bluetooth Headse

Posted by: GrYph0n Jan 19 2005, 06:26 PM



Logitech Mobile Freedom Bluetooth Headset


I have spent a little time with this remarkable new Bluetooth headset that Logitech will be releasing at the end of October 2004. If you are tired of sounding like you are in a tunnel or not being able to talk while in your convertible, or when driving with your windows down then this is the headset for you. I have also been using the Motorola HS-810, which is a good headset but pales in comparison when put up against the Logitech Mobile freedom.

I used my HP iPAQ 6315 to review this product. The Mobile Freedom pairs seamlessly with the iPAQ 6315 each and every time. I noticed with my Motorola headset that if I ever went out of range from the phone then I would have to reset Bluetooth all together to get them to re-pair, this was not the case with the Logitech. I could turn it off and on and each time it paired instantly without touching the phone at all.



Now with all that said lets get down to quality of sound.

When I made calls with the Motorola headset people on the other end would tell me that it sounded fine but they knew that they were on a headset or some would ask if they were on speaker phone. However I don't think anyone that I spoke with knew that they were on a hands free until I told them when I asked about the true quality of sound. One friend of mine actually said that while on the Logitech that the sound was clearer than when not on a hands free at all. The WindStop technology that Logitech used on this is simply amazing.



How Does WindStop Work?

This is what Logitech tells us about WindStop.


Headsets for mobile phones are designed to be sensitive to noise in order to optimize transmission of the human voice. However, many headsets have difficulty separating the human voice from amplified background noise – or air movement that the headset interprets as noise. Every day, mobile phone calls are brought to a screeching halt because of a little breeze. While a little wind may not feel like much to a caller, to the audience on the other end of a mobile phone call, it can sound like a Category 5 hurricane.

Logitech, a leading manufacturer of mobile accessories, has developed a patent-pending technology called WindStop™ to solve this problem. Available for the first time in the new Logitech® Mobile Freedom™ Headset, WindStop will help mobile phone users cut through the wind – and dramatically reduce the interfering noise.

Talking up a storm

Arguably, wind noise is one of the most annoying aspects of using a mobile headset outdoors. The slightest breeze can bring a conversation to an end – or result in a mad dash for a wind-free environment. In an emergency situation, neither of those scenarios is desirable.

Wind noise creeps into other situations, as well. An air conditioner set as low as medium level will create noise on most mobile headsets. Or when the caller is driving with the windows rolled down, riding a bicycle, riding in a convertible, or even walking at a moderate pace, microphone sensitivity to wind can offset the convenience of having a hands-free mobile phone headset.

Why Wind Noise Happens

Under normal conditions, a headset’s microphone expands and contracts from varying air pressure created by the human voice, which then is converted to an electrical signal and sent via the telephone to the listener.

In windy conditions, the microphone is hit with random bursts of air that force the microphone element to expand and contract beyond its performance range, and the element clamps either open or shut. To the listener, the noise alternates between unintelligible static noise and dead air, making conversation virtually impossible.



Logitech WindStop (above) blocks wind noise but allows normal speech to pass through the sintered plastic material. The result is clear voice transmission, even in windy conditions.

Getting Rid of the Noise

Traditional methods of reducing wind noise have included the use of large, bulky foam or fur microphone covers – as seen on many broadcast boom microphones. This method is quite effective, but it is impractical for the small microphone on a mobile phone headset.

Some headsets try to address wind noise by using sophisticated electronics, such as digital signal processing (DSP). This technology is successful in minimizing background noise such as airport loudspeakers, using a mathematical algorithm to identify and filter specific tones. However, wind noise wreaks so much havoc in the microphone element that a clean signal simply cannot be extracted from the source. DSPs also require more power, which can lead to shorter battery life in a headset.

Considerations

Logitech evaluated traditional wind noise reduction technology and merged it with a new approach. The idea for WindStop is a revolutionary – yet somewhat simple – way to reduce wind noise without using expensive electronic components, solving the noise problem while keeping the headset affordable.

The concept sounds simple – take the idea of the bulky foam microphone cover, shrink it, and integrate it into the mobile headset microphone. This concept, of course, is simpler than its execution. The microphone cover has to be manufactured with consistent quality. It needs to look good, feel good, and match the rest of the headset materials and colors, because modern-day headsets are often seen as a fashion accessory. The cover also needs to be impervious to heat. And, above all, it needs to be inexpensive.

The Answer: Logitech WindStop
After testing many different materials, Logitech identified a sintered plastic material that is porous enough to allow normal speech to pass through clearly, but stops the random perturbations caused from bursts of air, such as wind noise. The material employs miniature powdered plastic particles that are fused — or sintered — and packed tightly together.

The sintered plastic is durable — Logitech’s rugged testing process includes a drop test onto concrete from a height of three feet. The thickness and robust material and size of the spheres are unaffected by temperatures of up to 150 degrees Fahrenheit. The headset remains fashionable because the sintered plastic surface and microphone don’t require any more space than a traditional microphone.

The WindStop material created another challenge, however. For a microphone to function properly, a defined volume of still air is required around the microphone. With this in mind, Logitech designed an acoustic chamber to surround the microphone, which is mechanically suspended. This suspension helps minimize mechanical vibrations that can cause an echo. The sintered plastic material is wrapped around the microphone, forming a chamber, and sealed at the bottom to ensure that sound can reach the microphone only by first traveling through the WindStop barrier layer. Human voice passes through the barrier, creating vibrations in the acoustic chamber and a clear, crisp sound. Meanwhile, wind is blocked out.

Logitech testing has shown that WindStop technology eliminates 18 to 20 decibels of wind noise. In addition, WindStop is also a solution that requires much less power than the majority of DSP-based headsets – the Logitech Mobile Freedom Headset has a battery life of more than seven hours of talking time.



What I found...

Granted WindStop doesn't eliminate wind noise 100% but it does a very good job. For testing purposes I put down all the windows in my Jeep and set cruise control at 70mph to see how well the WindStop actually works. Well to my surprise I was able to carry on in a normal conversational tone and could hear every word that was said through the super loud speaker. Actually the speaker can be turned up loud enough to be uncomfortable so be careful on that. In noisy conditions I found that 2 to 3 below max was ideal in a noisy environment. The WindStop also seemed to cut down on background noise (i.e. my radio playing at normal levels). I called Sean himself using the Logitech Mobile Freedom with my head out the window driving at 65mph, and he could hear me well enough to carry on a conversation (head was out the window for testing purposes only, I do not recommend that you drive with your head out the window).



So whats it gonna cost?

The Logitech Mobile Freedom is designed to be an affordable Bluetooth headset, the suggested retail price is only $69.99 which is pretty good when looking at other headsets. They will also be offering a Pro model that will have a case/charger and is suggested at $99.99. Both models are Bluetooth 1.2 and have AFH Technology (Frequency Hopping), but the device must also have BT 1.2 inorder for the AFH to work.



Overview...

When compared to the Motorola HS-810 the Logitech is a little heavier but feels more comfortable while on the ear. The clip that holds it securely to your ear rotates 360 degrees and allows for ambidextrous use. I had the Logitech on for a few hours one evening while on the road, and I honestly forgot that I was even wearing it. It has 7 hours of talk time, and up to 250 hours of standby. It is the loudest headset that I have ever used Bluetooth or not. It's only drawback is the fact that you can not redial the last number called from the headset. I think that the Logitech will be a steal at $69.99 and is now available directly from Logitech, and will also be sold at CompUSA.

If you have a Bluetooth enabled phone I think that the Logitech Mobile Freedom headset will be a must have...

http://www.logitech.com/index.cfm/products/details/US/EN,CRID=1632,CONTENTID=9502

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