General > General Technical Chat

This Janet Jackson BASSLINE breaks laptops

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BrianHG:

--- Quote from: Halcyon on January 09, 2023, 07:50:04 am ---
--- Quote from: tom66 on January 08, 2023, 11:43:02 am ---
--- Quote from: BrianHG on January 08, 2023, 03:34:11 am ---Note, my HP laptop has an accelerometer feature for the HD protection which can be enabled/disabled in the advanced HP tools.  I wonder if the music is just tripping such a protection feature in these laptops.

--- End quote ---

I think this is it.  The video in Adam's video @1:33 shows the laptop powering off completely.  If the HDD crashed, you might expect a lock up of the system or a BSOD, not a power down.   I know that the accelerometer protection on my older Lenovo laptop powered the whole system down.  Not sure why - maybe to provide more consistency for the user after a drop (a hung system is worse than a powered-off one?)

--- End quote ---

I'd suggest this is poor design, or something was wrong. Laptops are designed to be portable, moved, tilted, picked up or otherwise shoved about. I'd be pretty pissed if my laptop powered off every time I moved it. It would be going right back to the shop for a full refund.

Hard disk interfaces (and operating systems) have for decades been designed in such a way that if there is a delay in accessing media, then the system will cope with that and simply wait.

--- End quote ---
  I completely agree.  I saw a youtube video illustrating the bug on a Toshiba laptop.  What was illustrated that the windows HD file access was paused a few times while playing the song.  However, this just may have been just a slow laptop, or swap-file access.

  You do know that free-fall mems accelerometers cannot sense gravity.  All they can can do is measure acceleration in 3 axis.  Their measured acceleration needs to go through a complex formula to determine if there is a true drop.  Calculation on the older mems units, like the .pdf I linked to, which has an illustration of the waveform as a free fall begins, continuously performs this calculation built into the mems IC and there are a set of controls to set the filter's 'window' frequency rolloff, response time and threshold sensitivity.  When set high enough, looking at the waveform provided in the .pdf, it is something which can be easily tricked even with a very low volume, but particular sound which mimics that window's opening of an object beginning to accelerate exactly 9.8m/s2.  All other signals are rejected by the 'free-fall' detector's formula.  This means no solid tone.  No impact.  No closing laptop lid.  No lifting up, or lowering down of the laptop.  You need the effect of Earth specific gravity drop.  Note that other mem accelerometers, like those from NXP, had to use a MCU to run the calculation to detect the free-fall pattern and again, there are online papers on how to do this while rejecting all other forms of acceleration.

mushroom:
Wasn't a laptop, wasn't Janet Jackson.
20 years ago, I repurposed as PC speakers a pair of small shelf speakers I built in the mid '80. Put them on the desktop. Also was sitting on the desktop an external 5.25" backup HDD. As soon as I played some music, the HDD died.
Just desk resonance, and it didn't take long !

Can't remember what I was testing the speaker+amp with. At this time, probably some BNWOHM or hair metal MP3 the mule brought to me...

SiliconWizard:

--- Quote from: EEVblog on January 09, 2023, 05:14:55 am ---
--- Quote from: SiliconWizard on January 07, 2023, 09:01:24 pm ---
--- Quote from: wraper on January 07, 2023, 08:49:14 pm ---
--- Quote from: Benta on January 07, 2023, 08:43:25 pm ---I call bullshit as well.
I read the story elsewhere (can't find it right now, sorry), but the point was that extremely agressive copy protection wreaked havoc on Win machines (as always). It's a Big Music plus Microsoft thing.

--- End quote ---
The story is not about DRM but about vibration at certain frequency causing HDD malfunction. FWIW HDDs are sensitive to vibration, so the story has some plausibility.

--- End quote ---

Yep. The less plausible part is that the laptop's speakers would have high enough output for low frequencies to cause any issue.
Those tiny speakers usually have a pretty poor low-freq response. So it sounds pretty unlikely to be able to couple vibration with enough amplitude to cause damage to a hard drive. So yeah, not impossible but rather unlikely.

But it's a funny story nonetheless.

--- End quote ---

Yep, I'm in that camp as well. Technically possible, but highly unlikely in practice.
The hard drives would have been vibrationaly frequency sweeped during operation to verify this isn't an issue.

--- End quote ---

If it did happen, then it would essentially be a defect with the HDD design (and testing), and it's very typical, and very "clickbaity", to carefully avoid pointing to the HDD vendor and amuse people with a funny narrative. Yeah, it's just the bassline, dudes. ::) No wonder the topic is being relayed at an amazing speed by a ton of high-viewed Youtubers.


SiliconWizard:

--- Quote from: BrianHG on January 09, 2023, 08:18:28 am ---  You do know that free-fall mems accelerometers cannot sense gravity.  All they can can do is measure acceleration in 3 axis.

--- End quote ---

They do not sense gravity, but they can determine it indirectly by sensing the reaction force when the device is stationary. It's actually an annoyance when you want to determine linear acceleration only with those accelerometers. A MEMS accelerometer lying flat (and still) on a table will measure ~1g along the Z axis, and close to 0 along X and Y.

In pure free fall, the measured acceleration on all 3 axis will be close to 0. So you can detect free fall. To some degree.

Now it's not 100% accurate, but merely taking the norm of the measured acceleration vector is usually enough to determine free fall. When the device is standing still on a surface, whatever its orientation, the norm will be close to 1g. When it's in free fall, it will be close to 0g. Of course there can be specific motions that could somewhat make this very simple approach fail, but it's usually good enough.

wraper:

--- Quote from: SiliconWizard on January 09, 2023, 07:54:26 pm ---If it did happen, then it would essentially be a defect with the HDD design (and testing), and it's very typical, and very "clickbaity", to carefully avoid pointing to the HDD vendor and amuse people with a funny narrative. Yeah, it's just the bassline, dudes. ::) No wonder the topic is being relayed at an amazing speed by a ton of high-viewed Youtubers.

--- End quote ---
Actually its almost a miracle hard disks can work at all with vibrations present considering track width in nanometers.

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