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Monday
Sep262016

Anker, AirPods and the Physics of Bluetooth

This is a hands-on product review of the Anker “SoundBuds Sport IE 20” Bluetooth earphones and a hands-off bashing of the design of upcoming Apple AirPods. The $30 cost of the Ankers was an experiment, which turned into a rather useful purchase to accompany my iPhone.  I explain why physics is the limiting factor to the performance of these products.


I have been using these $30 Bluetooth headphones now for about 2-3 weeks. The Anker SoundBuds Sport IE 20 was my first Bluetooth device since I abandoned the Jawbone Bluetooth earpiece years ago due to a serious dropout problem; the problem, however, was with PHYSICS and not the product itself (which I otherwise rather liked).


This purchase was fueled by the Apple AirPods announcement. Those jewels will set you back $159 per pair, and the use of the word "pair" is key.  Well, it's really three pieces... the two wireless earbuds and the rechargeable charging case.


These Ankers use a cable from USB to some micro connector to charge their batteries. A multi-color LED gives you charging information which is quite simple and useful.


The wire between the two earpieces does more than meets the eye. It distributes audio signals and power, and apparently serves as the antenna. But, the most important use is keeping them around your neck when you pull them out of your ears. The most surprising finding in my experiment: that wire is absolutely necessary to make these ergonomically useful.


The Ankers have a clever feature behind their utilitarian-shaped flat backs: magnets. When you put the backs together, they stick to each other which does two important things. It turns them into a necklace around your neck, which is a very convenient, useful and durable storage position. It also disconnects their power, saving their (very small) batteries when they are not in use. THIS is brilliant design. They don't seem to quite know how to trumpet these features based on the adverts that I have seen, making them a triumph of Engineering over Art. One look at the cinder-block inspired design confirms that Art had left the building.


The Ankers come with a little bag of at least three different sizes of rubber "grommets" for fitting to your ear canal. Then there is some other rubber widgets with horn-shaped protrusions to help keep them in your ear. All of which is user-customizable and optional. I needed to use the large size grommets, and that's it. They work perfectly, sound good, and don't fall out. When all is said and done, there is remaining this little bag of spare rubber parts sitting on your desk. Maybe you'll change your grommet sizes some day, maybe you won't. But, it's a reminder that Anker acknowledged that not everybody's ear is the same shape. Apparently Jony Ive has not.


And then there are the audio dropouts: the annoying loss of connection between your Bluetooth earphones and your audio source.  And it’s due to physics, not Anker nor Apple nor Bluetooth per se.


I call it the "Right-Ear Left-Back-Pocket Problem" (RELBaPP). Bluetooth operates on the 2.4 GHz frequency band, which is the same band as WiFi. And microwave ovens.  Your body is a very, very good absorber of 2.4 GHz energy.  Mostly, it’s because you are a carbon-based bag of salty water.  Radio frequency (RF) energy that hits your body will be largely absorbed and turned into heat.  Remember that microwave oven?  Same deal, it's just that you are not a roast chicken and the heat generated is many, many orders of magnitude smaller.


Radio waves, like light (which are radio waves), want to travel in a straight line.  The problem is that the straight line between your right ear and your left rear pocket goes right through a big carbon-based bag of salty water.  So, does the path between your right ear and your left ear.  Guess where I keep my iPhone.  Yep.  


So, in three weeks of using the Anker bluetooth headphones, I have had audio dropouts.  When I am standing up, walking about my workshop and listening to podcasts, they are infrequent and brief.  If I sit at my desk, they are more frequent.  Subjectively, however, it’s better than my old Jawbone earpiece which was eventually abandoned due to its dropout behavior.  And that MAY be due to the use of the Anker’s connecting wire (or part of it) as the antenna, it’s size making it more efficient than a tiny internal antenna.  


(Surprisingly, Dear Reader, this antenna designer will not bore you with an antenna lecture at this time.  You’re welcome.)


The Ankers are a keeper.  They are useful, convenient, and fill a need for me.  I listen to lots of podcasts, and a little music.  When I am working in my shop or washing dishes, the lack of wires is welcome.  Their sound attenuating design helps in noisy environments.  The battery life is adequate, and I am unbothered by the need to plug a cable into them for charging.  At $30 for the Ankers, it’s a rather painless purchase.


Enter the Apple AirPods.  I’d like to be wrong, but I think they are going to be a disaster.


Their shape appears to be the same as the latest Apple ear buds with the wires cut off.  Well, that shape never fit my ears (unlike the previous generations), and there was no solution.  So, in my office, in my “Apple Stuff” box, there are multiple copies of those fashionably-designed earbuds in their fashionably-designed plastic boxes, unused.  Nobody in my Apple-equipped family uses them.  I have friends that echoed the same situation, and Apple has no recompense.  If you don’t have a fashionably-designed ear, you can’t use these ear buds.  And the AirPods appear to have the same shape with no further solutions offered.  Maybe a carefully crafted bit of duct-tape can help you customize your $159 AirPods.  How unique they will be!


And when you need to remove your headphones because you are having a conversation with a coworker, what do you do?  With my Ankers, I pop one out and let it hang by the wire.  Or, take both out and click them together around my neck.  The AirPods will need to be shoved in a pocket, or the charger case which you are (additionally) carrying in your pocket.  Their size is their liability.  (It took fifteen seconds after the product announcement for a company to offer an aftermarket “string” for the AirPods.)


If an AirPod pops out of your ear by accident, it's gone.  And at $159 per pair, it’ll be interesting to see what Apple will charge to sell you a single one.


Neither Anker nor Apple can change physics.  There’s a lot of salty water between either earpiece and your left back pocket.  And between each other.  But don’t worry, I am certain that Apple did extensive testing during the RF design of the AirPods.  There is no way they would release a product that won’t work as designed around the human body.  Between computer simulations, testing with human-body analogs, and beta-testing with real people, you KNOW their product will work insanely great.


And they’re still compatible with your old iPhone 4.  As long as you’re holding it right.