“Way to go, CA Design Team! Great kudos for your layout work.”
so says Jeremy Huffman, the Engineering Lead of the awesome team we were a part of, from Doppler Labs!
“At first glance the two earbud PCBAs look like mirrored versions of the same board, but they are definitely not. (Mirroring a board layout may seem simple in theory, but remember chip pinouts do not change, so this is a much larger task than it appears!) Anyone who has done board layout knows how much of a pain it is to tediously fanout a BGA micro-controller, so we tip our caps to the effort put forth by the Here One engineers to design two unique PCBAs to fit into this tight space.”
TECHNICAL
Here One Earbuds Teardown
The Apple AirPods were undoubtedly the most widely publicized wireless earbud release of last year and, here at Mindtribe, we were impressed with the compact design and layout of the internals. In fact, we gushed about them in a previous blogpost. The wireless headphone industry has not been idle in the meantime, though, and a whole slew of wireless earbuds have hit the market with a smorgasbord of features.
One product, the Here One wireless earbuds, sets to shape the way consumers interact with their devices by incorporating “smart” noise filters – a feature the existing Apple AirPods do not offer. They also boast the nifty, new low-power Near Field Magnetic Induction (NFMI) communication protocol for synchronization between earbuds, in addition to the usual Bluetooth communication to your phone, all packed into a neat little ear-stuffable button. This is in comparison to the AirPods, which use only Bluetooth.
We were curious how these extra features affected the Here One design, and how they differed from the AirPods. We expected to find at least one additional microphone inside each, as well as some powerful Digital Signal Processors (DSPs).
First though, some user testing: we found the user interface of the Here One to be pretty nice once they are in the ear, but the pairing process to be a bit dodgy. Whereas the AirPods could be immediately detected and paired, Here One setup required multiple back-and-forths between the app and phone Bluetooth settings, creating a frustrating user experience. Although both had occasional dropouts during voice calls, the Here One exhibited a higher Bluetooth dropout rate overall. Bluetooth antenna placement will definitely be something to pay attention to during the teardown.
Audio quality-wise, both types of earbuds had similarly good-quality sound. The noise cancellation feature of the Here One (not a feature of the AirPods) worked well indoors, but would be overwhelmed by wind gusts when outdoors in San Francisco. Still, a neat feature!
The Here One ambient filters were really fun to play with. After folks in the office got their chance to actively tune each other out and add real-time echo to each other’s voices, we pulled out the Exacto blades and tweezers to find out what was inside these earbuds. (We’ll save the charging case dissection for another blog post.)
To start, the plastics snapped apart surprisingly easily. Unlike the AirPods, which were mostly fixed with glue and ultrasonic welding, the Here One earbuds had enough space for some tiny notches and hooks.
Plastics, with focus on notches, left earbud
To turn ambient sound on/off, the user taps the outside plastic grille. Since there’s no obvious mechanical depression or click, we guessed the tap must be detected via an accelerometer or capacitive touch pads.
Sure enough, stuck to the center of the grille cap you immediately see a small circular flex with two spring contacts. These are two capacitive touch pads. A typical finger tap would overlap both pads.
Removing the black dust protection sticker ring from the grille gives us the Bluetooth antenna, which has been custom imprinted onto the plastic. Imprinted antennas like this can be created using LDS (Laser Direct Structuring), in which a laser is used to create a custom 3D antenna directly onto the plastics. These must be specially tuned, and are more difficult to manufacture because they require LDS-grade plastics, any cracks in the plastic can have adverse effects on the antenna tuning, and you have less flexibility in cosmetic finish.
This ties back to our Bluetooth pairing issues in user testing. Having the Bluetooth antenna as far away from the head as possible definitely helps, but given this has to sit in your ear, there were limits to the Here One antenna placement. The AirPods avoided this issue by having their antenna run along the battery stem, outside of the ear, providing better Bluetooth performance.
Underside of grille cap with bluetooth antenna exposed, left earbud
