xMEMS Announces World's First Monolithic MEMS Speaker (anandtech.com) 25
An anonymous reader quotes a report from AnandTech: In the last few years, semiconductor manufacturing has become more prevalent and accessible, with MEMS (Microelectromechanical systems) technology now having advanced to a point that we can design speakers with characteristics that are fundamentally different from traditional dynamic drivers or balanced armature units. xMEMS' "Montara" design promises to be precisely such an alternative. xMEMS is a new start-up, founded in 2017 with headquarters in Santa Clara, CA and with a branch office in Taiwan. To date the company had been in stealth mode, not having publicly released any product till today. The company's motivations are said to be breaking decades old speaker technology barriers and reinventing sound with new innovative pure silicon solutions, using extensive experience that its founders have collected over years at different MEMS design houses.
The manufacturing of xMEMS' pure silicon speaker is very different to that of a conventional speaker. As the speaker is essentially just one monolithic piece manufactured via your typical lithography manufacturing process, much like how other silicon chips are designed. Due to this monolithic design aspect, the manufacturing line has significantly less complexity versus voice coil designs which have a plethora of components that need to be precision assembled -- a task that is quoted to require thousands of factory workers. The company didn't want to disclose the actual process node of the design, but expect something quite crude in the micron range -- they only confirmed that it was a 200mm wafer technology. Besides the simplification of the manufacturing line, the MEMS speaker features higher consistency membrane movement which allows higher responsiveness and lower THD for activate noise cancellation, compared to a more variable voice coil design. The speaker's frequency response covers the full range from 10Hz to up to 20KHz, and the design is said to be able to compete with planar magnetic designs, promising to have only 0.5% THD at 200Hz -- 20KHz.
"As these speakers are capacitive piezo-driven versus current driven, they are able to cut power consumption to fractions of that of a typical voice coil driver, only using up 42uW of power," adds AnandTech.
The manufacturing of xMEMS' pure silicon speaker is very different to that of a conventional speaker. As the speaker is essentially just one monolithic piece manufactured via your typical lithography manufacturing process, much like how other silicon chips are designed. Due to this monolithic design aspect, the manufacturing line has significantly less complexity versus voice coil designs which have a plethora of components that need to be precision assembled -- a task that is quoted to require thousands of factory workers. The company didn't want to disclose the actual process node of the design, but expect something quite crude in the micron range -- they only confirmed that it was a 200mm wafer technology. Besides the simplification of the manufacturing line, the MEMS speaker features higher consistency membrane movement which allows higher responsiveness and lower THD for activate noise cancellation, compared to a more variable voice coil design. The speaker's frequency response covers the full range from 10Hz to up to 20KHz, and the design is said to be able to compete with planar magnetic designs, promising to have only 0.5% THD at 200Hz -- 20KHz.
"As these speakers are capacitive piezo-driven versus current driven, they are able to cut power consumption to fractions of that of a typical voice coil driver, only using up 42uW of power," adds AnandTech.
My brother just bought a guitar (Score:3)
CNC machines and automation in manufacturing have made it possible to manufacture incredibly high quality merchandise insanely cheap.
Re:My brother just bought a guitar (Score:5, Funny)
from a European manufacturer that he tells me is $130 bucks and the equal of guitars 5 times it's price today and 10 times it's price from when he was a kid.
So... Sounds like, for the same total cash, he can get 5 of these guitars and set them up in a RAIG-5 configuration for redundancy ... :-)
Re:My brother just bought a guitar (Score:5, Funny)
Heck, maybe a Beowulf Gluster would be possible.
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Something like this 9-neck gluster? https://live.staticflickr.com/... [staticflickr.com]
Don't know about that, they share a common backplane -- I mean body. If it fails, they all go down.
GAS (Score:2)
So... (Score:1)
Re: So... (Score:2)
Maybe more affordable?
I came here to ask the similar question of how are these different.
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Been checking this for a while... (Score:3)
No measurements available (other than the claimed few points - but there's nothing about driven cavity sizes, distance, etc), and they don't tell you how big or how expensive the required 30V power supply is.
I've played with the MEMS speakers from uSound (same kind of thing) and while they were interesting, they didn't have even the same level of output as a typical dynamic speaker of the same area (MEMS can do a few hundred microns of motion, at best; an 8mm diameter dynamic can do 1mm one way), and required about $15 in power supply and drive circuits (compared to $0.40 for a standard amp, running off of a single 3.7V rail).
I'll believe the claims when I can see actual AudioPrecision test results with fully documented conditions - or I get one to run through my own AP and test systems.
Re:Been checking this for a while... (Score:4, Informative)
The article provided some frequency response graphs. They are terrible. It looks like they're only suitable for earbud type use, and even then a great deal of frequency response shaping will be needed before they can be considered acceptable for medium-fidelity use at low volume.
It may be that they just slapped their MEMS driver into the first earpiece they could fabricate, without doing any actual acoustic design. It certainly looks like there's a fundamental peak and a third harmonic, and that's the sort of thing that can be reduced or fixed entirely with damping and proper mechanical shaping.
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headphone use would explain a lot of it. (Score:2)
headphone use would explain a lot of it, because frankly otherwise the W mentioned doesn't make sense nor does it how would it have enough movement in any reasonable size to rival a normal speaker for bass response without shattering
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This consistency means you can compensate for it easily and without measuring the individual devices.
Low freq response (Score:3)
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It could work by heterodyning two frequencies which lie within the (assumed to be very high) peak frequency response curve for the transducer. You would not hear the carrier frequencies, only the resulting interference. It wouldn't even be that hard, just take one fixed tone and frequency modulate the second tone to the desired audible frequency. You still would not move a lot of air but it would make it possible to use these things in applications where that isn't necessary, e.g. ear bud speakers or teleph
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