If you’ve already read any of last month’s posts, you know that my fellow engineer Huan Nguyen failed to resurrect my prematurely deceased set of Beats Powerbeats Pro headphones. Once again following my long-standing mantra “When life gives you lemons, make lemonade,” however, I decided to go ahead and do a complete teardown of one of them, as the abundance of still and video footage of Nguyen that he captured during “surgery” and subsequently shared with me (and I subsequently shared with all of you ) only got as far inside them as the battery. I won’t be retracing his already documented steps, so make sure you check out Nguyen’s already published written and photographed play-by-play before continuing.
Here again are Apple’s “stock” images of the standalone headphones (in the same color as mine):
and with one of them placed in the charging case (the white version):
The charging case still works fine, so I keep it intact as a spare for the Powerbeats Pro replacement set I bought (fool me once, shame on you; fool me twice, shame on you?). I will make a repeat incision and further disassemble the right earcup, which Nguyen had originally cut with an ultrasonic blade. To be fair, however, my cut will not be from scratch, as at my request he left the cover detached on this handset to make it easier for me:
Here’s the standalone cover, front side first, showing the feature activation button:
And now the back side, revealing the “spring” button:
The switch activated by the button located on the battery cover is now obvious:
Also, readers, correct me if I’m wrong, but I’m pretty sure that’s the MEMS mic to the left of the battery cover, on the top of the kit. Remember that this particular model of headphones, whose presentation dates from early 2019, does not implement ANC, only PNR, so there is no need for multiple microphones for each ear. That said, there is two holes feeding the microphone with sounds from outside, which I will show you in a moment.
Let’s take that black plastic piece on the left:
To be honest, I don’t know exactly what the point of this piece is. It is not metallic, so it cannot provide any electrical shielding capabilities, nor can it act as a heatsink for H1 SoC (successor to Apple’s initial W1 chip for wireless headphones) below. It may simply provide additional structural integrity and protection from impact, moisture, etc. electrical circuit failure below. Also note that I never found a Bluetooth antenna, either separate or built into the PCB (nor iFixitas far as I can tell) so maybe it’s integrated into this piece as well.
Time to remove the PCB:
It turns out that this is a “sandwich” with many printed circuit boards:
From this perspective, you can see the “prongs” that connect to the charging contacts on the bottom edge of the headphones:
And this perspective shows you the switches corresponding to the two-button control switch along the top edge of the headset:
Now take a closer look at the two exterior view photos and you’ll see a small hole next to both the charging contacts and the two-button switch. These are the two vents that feed the microphone that I mentioned earlier. And if you look really up close, you can see the inner mesh connected to one of the outer vents, designed to keep dust and other particles from getting inside. I will show additional images of the holes and their mesh partners later.
Let’s fully unfold this “sandwich”:
One of the frustrating aspects of tearing down Apple products is that many of the ICs don’t have any markings on the top at all, and for those that do, they’re Apple-proprietary stamps that give no idea what’s inside the package. The previously mentioned H1 SoC (inherited from the newer H2) is obvious despite its attempt at anonymity. And I can assume that the IC near the charging “prongs” controls the headset’s power and battery refresh functions. But other than that…🤷♂️…
And here’s what’s left after extracting the PCB “sandwich”:
You can see that I cut a ribbon cable going to the handset during this part of the procedure. We already know there’s a speaker down there, as well as an infrared sensor that detects if the earpiece is actually in the ear (for example, pausing playback when the earpiece is removed):
so i suspect we will find not only a converter but also more chips. First though, what’s with that piece of metal on the left, under the already extracted PCB?
Actually it is two pieces of metal, the bottom one being a pretty strong magnet. It took me a minute to realize its main purpose; here’s how the headphones “grab” the charging case when placed in it (it also adds structural rigidity, of course):
To get at whatever was inside the handset, I combined a box cutter and a thin flathead screwdriver acting as a chisel:
Actually there is two more mini-PCBs connected together with another ribbon cable, with another ribbon cable coming out of the second mini-PCB (the one glued to the back of the speaker) and even deeper into the earpiece:
After cutting the first ribbon cable to separate the two mini-PCBs, I used the flathead screwdriver to delve further into the handset structure:
Inside, unsurprisingly, was the dynamic transducer with the infrared sensor underneath:
But one more good thing still awaited me. Do you see the grid in the first frame that follows?
Hold that thought for a minute. Let us now turn to something else mini-PCB, the two sides of which you’ve already seen (albeit slightly obscured) in previous chronological images:
Once you remove that, here’s what’s left:
What’s that in the second shot… more mesh? yes At first when I encountered it, I wondered if there might be (leaving aside previous comments without ANC) another microphone deeply embedded in the earpiece. But that didn’t make sense because the only thing he could “hear” would be what was coming out of the speaker. Then I realized that what I was actually looking at was a bass reflex port for enhanced low frequency reproduction that conveniently performs dual function of reducing ear pressure for better comfort during a long listening session. Apple/Beats marketers call it “microlaser barometric vent” is a little hyperbolic, but still smooth!
Speaking of microphones, I’ll finish with, as promised earlier, a more focused look at the two vents and their (microlaser?) mesh associates:
And with that, it’s all up to you for your thoughts in the comments!
—Brian Dippert is Editor-in-Chief of Edge AI and Vision Alliance and Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.
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https://www.edn.com/apples-beats-powerbeats-pro-no-repaira-teardown-though/