MEMS louspeaker

[S57UUU]

I came across this:



Except maybe for earphones, I can't see how this might work. Or is there a way?

[MarkT]

Hmm, I get a big whiff of something known to baffle brains.  Converting ultrasound to sound isn't normally an efficient process, to say the least.  And what about bass - you have to move lots of air - an affordable MEMS chip isn't big.

But without any useful details and numbers there's little to see here.

[ebastler]

I just scanned that video using Youtube's time slider. Half an hour of rambling and not a single diagram or table with data? (And opinionated rambling too, by someone who wants to sell that technology.) Sorry -- I don't know how this technology is supposed to work, and this video is not how I am going to find out about it.

In general, I would be skeptical regarding membrane sizes and oscillation amplitudes. How are they planning to move air for lower frequencies and relevant amplitudes? Is it one of those highly directed, phased array approaches?

[Kleinstein]

They may not have to move a membrane. I could imagine using a kind of micro pump.

[SiliconWizard]

Agree with ebastler, we almost learn nothing.

MEMS microphones have been a thing for a good while now and work well for their intended purpose - which is mobile phones (for most of the market) and then relatively niche applications outside of that. They work well and are sturdy, but with some specific limitations (like max SPL).

For loudspeakers, I can't really see how this could make anything other than very low-power speakers, probably for earbuds and maybe future hearing aids (if we can even make MEMS speakers able to deliver enough acoustic pressure).

[adx]

Not what oh where was I going with that. Ah, not watched the video, but it has the smell of being these drivers I posted this about on AAC a couple of weeks back:

Quite hard to work out what this is even for, let alone exactly how it works (I guess that’s what happens when you sit down with the “vice president of marketing and business development” . [that was for the article on their site, down to the unwanted emoji conversion]

Appears the speakers are really just earbud drivers and the 140dB only applies to that configuration, and they work by creating an ultrasonic resonance in chamber(s) which is then gated to provide net gas flow. They are a gas pump with controllable direction and flow. I guess crossover distortion would be a challenge, perhaps it uses phase shift at low levels to clean that up.

Nifty, but unobtanium for mere mortals.

[tszaboo]

The term MEMS speaker has been used for so many different things, that it became completely meaningless. For some companies it just means it's really small, and it has nothing to do with monocytic semiconductor processes.