[Jpoliachik]

> But why bother putting a real driver in here at all? Magnets not only add weight, they take up a lot of space. Looks like one corner Apple refused to cut on this tiny disk is sound quality.

I find it fascinating what tradeoffs are decided upon. Apple is arguably the best luxury brand in the world - and this is why.

[rand_r]

Apple’s unique ethos is technology as a means for creative expression. That’s why they’ve excelled in font rendering, colour accuracy, sound fidelity, and input-lag.

I think this value came from Steve Jobs, and I hope they never lose it because it imbues Apple with real human spirit. They’re more than just another profit-seeking company.

[gumby]

> They’re more than just another profit-seeking company.

I do like Apple but be real: this is how they garner their profits.

[baoqdau]

This is your brain on consumerism.

[ben-schaaf]

> That’s why they’ve excelled in font rendering

Not sure about the past, but without subpixel antialiasing they pretty much have the worst font rendering now.

[matwood]

Doesn’t this only cause issues on non-HiDPI screens.

[owlboy]

Can you elaborate?

[rand_r]

Basically, they assume you’re using a retina quality (aka HiDPI) display where each virtual or abstract pixel maps to four physical pixels in the display.

For example, you have a 27” 4K display, but set the resolution to 1920x1080 in System Preferences.

Mapping each virtual pixel to four physical pixels lets you render curves really crisply. However, on non-HiDPI where you don’t have pixel doubling, you have to use sub-pixel rendering to approximate curves.

One technique is playing with slightly shading adjacent pixels so that at a distance curves appear to be smoothed out. But for some technical reasons, Apple dropped support for sub-pixel rendering. It was too hard to do and the future is HiDPI anyway.

[spicybright]

Right? All it's missing is a Posted from my iPhone footer

[fnord123]

> That’s why they’ve excelled in font rendering, colour accuracy, sound fidelity, and input-lag.

That'll be why mac laptops connect to bluetooth speakers using the worst default settings for sound fidelity so it sounds like a dying frog.

And the input lag is quite terrible when the machine is under any load.

[dijit]

Input lag on an iPhone or an iPad is best in class. The Mac leaves much to be desired.

I have never had an issue with Bluetooth on the Mac. Maybe there’s issues if you’re doing audio recording on the headset, but that’s a limitation of bluetooth 4 and would be similar on Linux or Windows.

My Linux laptop likes to negotiate HSP (low quality but with audio recording) over HSDP (high quality) with my Bose QC35s, but the Mac is quite happy to dynamically switch as needed.

[fnord123]

Default bitpools on mac are very low for audio ime. To fix it, you can run the following:

https://www.reddit.com/r/apple/comments/5rfdj6/pro_tip_signi...

[ryneandal]

I've tried to use the mic on my airpods with my windows desktop once -- Bluetooth 4 mic output _definitely_ sounds like what he's describing. It's godawful and certainly an effective way to mete out punishment to those vendors you dislike via conference call. It's an immediate headache.

[fastball]

I'm sure that will be fixed once Apple inevitably starts building their own Bluetooth chipsets.

[gumby]

> you’ll have to wait until 2015: https://en.wikipedia.org/wiki/Apple-designed_processors#W_se...

[fastball]

* for computers.

From what I've heard, their chipsets don't have the same problems as the ones they use in macs.

[dangus]

The M1 Macs are essentially iPhone/iPad hardware. The latest iPad Pro shares the same M1 chip, and I imagine it shares most other components as well.

[Lammy]

It will also make them better hidden microphones :) http://in.bgu.ac.il/en/Pages/news/eaves_dropping.aspx

[tzs]

Is the magnet strong enough to stick the tag to ferromagnetic metals?

[gmrple]

Weakly, yes. Enough to hold its own mass at rest, but I don't think it would work with any type of acceleration. It will stick nicely to a neodymium magnet.

[gumby]

... Which I assume also mutes it?

[tzs]

I'd expect sticking the tag to some ferromagnetic surface, such as a fridge door, by the magnet to have about the same effect as gluing the tag to that same surface would which I would guess would be none.

Generally in a permanent magnetic speaker the permanent magnet is solidly affixed to the speaker housing.

The part that actually moves to make sound (the diaphragm) has a coil attached to it. The signal is sent through that coil, which produces a variable magnetic field that interacts with the fixed magnetic field of the permanent magnet.

This interaction produces a force that moves the coil, and thus also moves the diaphragm producing sound.

You could probably design a speaker where the coil is fixed and the magnet is attached to the diaphragm, but that is generally not done. You want the moving parts to be as light as possible so that it doesn't take a lot of energy to rapidly change their motion.

Consider a speaker playing an N Hz sine wave--it has to change direction 2N times per second, and between each direction change you want it to move far enough to move enough air to for the sound to be easily audible.

If the moving part is too heavy you would need a lot more force to accelerate it enough to move far enough to move enough air in the short time you have in order to reach a specified loudness, and then it would take a lot of energy to quickly change direction and do the opposite movement. Hence, the heavy magnet is fixed and the light coil moves the diaphragm).

Microphones are similar. There are moving coil microphones, but I don't recall seeing moving magnet microphones.

You might think it would also be the same with phonograph cartridges, but there you do find both moving magment and moving coil designs [1].

[1] https://www.audio-technica.com/en-us/support/audio-solutions...

[gumby]

Thanks for that great message!

The case I was thinking about was specific to the airtag. In this case a fixed voice coil moves a small permanent magnet attached to the diaphragm rather than the other way around (according to iFixit, quote below). So maybe a rare earth magnet oriented the right way could prevent the magnet from moving. There’s an air gap so it will have to wait until I can do an experiment.

Note from iFixit:

> Did you notice the “button” on the underside of the cover? That’s not a clickable button, like the Mate and SmartTag have, but rather the magnet we saw earlier in the X-ray. It sits right inside the donut-shaped logic board, nested into a coil of copper to form a speaker. You read that right—the AirTag’s body is essentially a speaker driver. Power is sent to the voice coil, which drives the magnet mounted to the diaphragm—in this case, the plastic cover where the battery lives—which makes the sounds that lead you to your lost luggage.

[gmrple]

Nope