3 ms·

In fact, almost everything has this problem. There seems to be (someone more knowledgeable please correct me) no way to avoid having a resonant frequency. The

In fact, almost everything has this problem. There seems to be (someone more knowledgeable please correct me) no way to avoid having a resonant frequency. The only thing that can be done is to change it. The resonant frequency of a glass can shatter it. The resonant frequency of a room can make it uncomfortable to be in. The resonant frequency of a bridge can tear it apart. We even have to take special precautions between 2.4GHz wifi and processors running at a 2.4GHz clock speed because they are capable of hitting the exact same frequency. As someone pointed out, the difference in manufacturers would have made the resonant frequency slightly differently between the specific drives.

User23 4y ago
A famous example is the old Tacoma Narrows Bridge[1]. [1] https://en.m.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940) https://en.m.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)
planede 4y ago
> The only thing that can be done is to change it. You can also dampen the resonance, to limit its response at the resonance frequency.
- joshspankit 4y ago
  Yes, but that’s a mitigation technique and not about eliminating the resonance frequency itself.
Mo3 4y ago
That's just so cool. And probably very annoying for a lot of people.
waswaswas 4y ago
One example of a precaution taken: Spread-spectrum clocking. Perfectly clocked signals have really high EM spectral peaks (noise radiated at particular frequencies). You can intentionally make the clock a little worse, spreading that radiation over more of the spectrum, and it will reduce the chance that those peaks break other things. https://www.microsemi.com/document-portal/doc_download/135439-white-paper-spread-spectrum-clocking https://www.microsemi.com/document-portal/doc_download/13543...
varispeed 4y ago
I had a DVR (digital video recorder) that was constantly recording the video feed into hard drive. It was in my bedroom. One day when I was cleaning I moved to box and didn't think much of it. Then in the evening I was getting ready to sleep and on the side of the bed where I sleep I could hear extremely loud boomy sound. It was driving me crazy, but as soon as I moved to find the source the sound "disappeared". Going back to bed and it's back again. I was going around the room like crazy trying to find the source, or maybe it was outside? Eventually I put my ear to DVR and noticed the sound was quite similar, but very faint. By doing this I moved the DVR and when I returned to bed the sound was gone. This was so frustrating. But I least I learned something how to find a source when something like this happens next time. Basically the unlikely positioning of DVR, my furniture and myself created loud resonance.
- Desti314 4y ago
  I'm curious if this is really the answer and not something like sound tunneling and amplification. Like when you stand somewhere further away and there is a spot were you can very clearly hear the people talking across the street or on a balcony
  - joshspankit 4y ago
    Natural amplification (especially through materials, which is what I would guess happened here) is resonance. It’s wild how pervasive it is.
  - JetSetIlly 4y ago
    An excellent demonstration of this is The Whispering Arch in Liverpool Anglican Cathedral or The Whispering Gallery of St Paul's in London.
namaria 4y ago
>The resonant frequency of a glass can shatter it. The resonant frequency of a room can make it uncomfortable to be in. The resonant frequency of a bridge can tear it apart. I love the roller-coaster of magnitude changes in the consequences listed: "shatter, unpleasantness, tear apart"

User23 4y ago

A famous example is the old Tacoma Narrows Bridge[1]. [1] https://en.m.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940) https://en.m.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)

planede 4y ago

> The only thing that can be done is to change it. You can also dampen the resonance, to limit its response at the resonance frequency.

joshspankit 4y ago
Yes, but that’s a mitigation technique and not about eliminating the resonance frequency itself.

Mo3 4y ago

That's just so cool. And probably very annoying for a lot of people.

waswaswas 4y ago

One example of a precaution taken: Spread-spectrum clocking. Perfectly clocked signals have really high EM spectral peaks (noise radiated at particular frequencies). You can intentionally make the clock a little worse, spreading that radiation over more of the spectrum, and it will reduce the chance that those peaks break other things. https://www.microsemi.com/document-portal/doc_download/135439-white-paper-spread-spectrum-clocking https://www.microsemi.com/document-portal/doc_download/13543...

varispeed 4y ago

I had a DVR (digital video recorder) that was constantly recording the video feed into hard drive. It was in my bedroom. One day when I was cleaning I moved to box and didn't think much of it. Then in the evening I was getting ready to sleep and on the side of the bed where I sleep I could hear extremely loud boomy sound. It was driving me crazy, but as soon as I moved to find the source the sound "disappeared". Going back to bed and it's back again. I was going around the room like crazy trying to find the source, or maybe it was outside? Eventually I put my ear to DVR and noticed the sound was quite similar, but very faint. By doing this I moved the DVR and when I returned to bed the sound was gone. This was so frustrating. But I least I learned something how to find a source when something like this happens next time. Basically the unlikely positioning of DVR, my furniture and myself created loud resonance.

Desti314 4y ago
I'm curious if this is really the answer and not something like sound tunneling and amplification. Like when you stand somewhere further away and there is a spot were you can very clearly hear the people talking across the street or on a balcony
- joshspankit 4y ago
  Natural amplification (especially through materials, which is what I would guess happened here) is resonance. It’s wild how pervasive it is.
- JetSetIlly 4y ago
  An excellent demonstration of this is The Whispering Arch in Liverpool Anglican Cathedral or The Whispering Gallery of St Paul's in London.

namaria 4y ago

>The resonant frequency of a glass can shatter it. The resonant frequency of a room can make it uncomfortable to be in. The resonant frequency of a bridge can tear it apart. I love the roller-coaster of magnitude changes in the consequences listed: "shatter, unpleasantness, tear apart"