"Airpods – a Speculative Teardown" by Nick Hunn a GREAT read!

Adding to all the ballyhoo around iPhone7's missing headphone jack is Nick Hunn's "Airpods – a Speculative Teardown" blog post. Boy, a sharp mind is a beautiful thing to behold.

Blow-by-blow, he "reverse imagineers" Apple's new wireless EarPods detailing:

  • How they might utilize A2DP and BLE (Bluetooth Low Energy) to coordinate the two EarPods and remain compatible with other phones.
  • How audio quality is enhanced mostly by stronger radio signals.
  • How the shape of the EarPod enables a lot of this cool stuff to happen.
  • How and why the charging case is likely smartened up by the W1 chip.
  • And most importantly: A very detailed list of what the W1 chip might include and why.

I like to post guesses...this guy seems really good at it.

What he didn't speculate on is why Apple permitted themselves to continue to produce it in acoustically an ear-bud design. Ear-buds (intra-concha earphones) sit in the bowl of your ear and don't make a seal with the ear canal. This is the worst type of acoustic coupler configuration of all headphone types. It just doesn't seal and looses bass....and that's what all the kids want. (Me too.)

My guess is Apple doesn't want to deal with the all the different earphone tips and the discomfort of IEMs. So they stuck with the crappy acoustic seal and the W1 chip has enough DSP capacity to do some corrective EQ.

Guess I'm going to have to get my hands on a pair.


woofer's picture

where are the vas deferens, not labeled in the schematic

jeffporter's picture

the seminal vesicle is there, but they labeled it as a dual accelerometer...

ultrabike's picture

have those. The came with an ipod nano I got proly about a decade ago I think.

They sucked. There are ipods with lightning connectivity though.

Tyll Hertsens's picture
These are the new wireless ones for the iPhone7.
ultrabike's picture

No no, I get it. It's the driver/housing design. It seems the new wireless follows the earbud approach instead of the later earpod design which IMO was a size-able step-up.

My nano came with the earbud type approach that doesn't seal well. I used to run and listen to tunes with them and was very disappointed. The earpod approach would have been a win IMO.

EDIT: CRAP! Those new wireless thingys ARE using the earpod approach. Welp, I didn't think those were that bad. I think they are almost IEMs, but not quite. Sorry about the confusion Tyll.

Shardnax's picture

I love the animation. Will you be writing a review or only adding them to the measurement database?

Arve's picture

"What he didn't speculate on is why Apple permitted themselves to continue to produce it in acoustically an ear-bud design. Ear-buds (intra-concha earphones) sit in the bowl of your ear and don't make a seal with the ear canal. This is the worst type of acoustic coupler configuration of all headphone types. It just doesn't seal and looses bass....and that's what all the kids want. (Me too.)"

The problem here is best summed up by "Apple doesn't primarily sell stuff to kids, hardcore audiophiles or people who spend their days on /r/headphones, SBAF or Head-Fi".

While listening to music may be better on a pair of IEMs, it's also pretty uncomfortable to have a two hour long phone call on them - the seal means that instead of hearing your voice like you do when speaking normally, it's reduced to bone conduction, which is fatiguing, and even unnerving. And that is where Air/EarPods reign supreme. For serious listening on the go, I'll always a pair of IEMs, but if I'm expected to have a conversation of any kind, off they go, and the EarPods come out.

(There is also the second matter of an open earphone/earbud allowing the wearer to maintain better situational awareness, which is of some importance in urban environments)

tinyman392's picture

I feel that the ADDIEM were the closest they got to the audiophile crowd. They aren't bad, though there was a lot they could have done to make them better. I honestly was hoping they would release a wireless model of those (like the AirPods) because I did enjoy those quite a bit (until the tips started detaching into my ear constantly). Maybe next year though.

sigma's picture

Now, as anybody who would read a site like this, I take sound quality very seriously, but I am conviced Apple made the right call here regarding sealing.

First of all, there is a large number of people (including me, after too many years of IEM use) who will not accept canalbuds no matter how good they sound because it HURTS to put things in their ear canals.

Secondly, the occlusion effect makes walking around with sealing earbuds a completely unacceptable experience because it amplifies the sounds of steps. This is a MOBILE phone accessory so this is a very important consideration. Sealing non-closed earbuds like the ones Sony makes are better about this but still not as good as non-sealing.

Then there's microphonics, which are made worse by the seal.

You also have to take into consideration that this, like the earpods, is primarily a hands-free set. Bass response is not the top priority here, the human voice frequency range is. So sealing canalbuds cause all these problems just to solve a problem that isn't even relevant to the sound quality in their intended use!

LytleSound's picture

These new 'phones from Apple have no bass and any amount of EQ applied to provide the bass will produce harmonic distortion with pronounced 2nd-order harmonic output. The GOOD thing about this type of distortion is that the auditory system fills in the missing fundamental so an increase in bass is perceived, although it is not as fulfilling as the real thing.

For years, the leak caused by a loose acoustic coupling to the ear has been taken as an advantage for fitting hearing aids to those with high-frequency, often noise-induced, hearing loss. It allows the use of the ear canal's natural resonance to present maximum energy to the eardrum above 1500 Hz with a 12-dB/octave roll off of the frequencies below 1500 Hz (the exact high-pass cutoff frequency depends upon how tightly the devices seals the ear canal, or the effective ratio of the cross-sectional area of the leak to that of the cross-sectional area of the ear canal for those who are math-inclined).

Also, there is no reason that fitting an insert earphone should hurt. If one choses the wrong-sized ear tip and forces the fit, then the fitting may hurt after a while. The solution is to obtain a custom-molded earmold made of medical-grade materials, even if foam, silicone, or acrylic. A comfortable fitting may also be obtained by by using Westone's Comply foam tips. This will allow a tight enough seal to provide a good bass if the earphone is capable.

Here's a test I currently use: First the earphone must be able to provide a 50 Hz signal - many can't. Second, use a downloaded function generation program such as Keuwlsoft's Dual Channel Function Generator. Third, set the waveform to triangular (even-numbered harmonics) with a fundamental of 50 Hz. Fourth, set the output level to 50% so that the electrical signal is mostly free from distortion. Fifth, after inserting the insert earphone with the best-fitting tip or custom earmold, drive the left and right earphones separately. The loudness should be about the same (set the volume of the phone to full). Then play both channels at the same time and the perceived tone should be in the middle of your head. If this is not the case and the earphones are wired in phase, adjust the fit of the earphone away from the side on which you hear the tone until the tone image centers. (I have an atelectatic right eardrum so I have to perform a Valsalva procedure to inflate my right middle ear, otherwise I head the 50 Hz tone on my left side no matter what). Fifth: enjoy, the open E from a bass guitar should be able to rattle your brainstem ❿.