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63hz/85hz unexplainable hum

ThatHaole

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Sep 25, 2024
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I noticed a 63hz hum in my house that switches intermittently and randomly to 85hz and back to 63hz, holding each tone for random lengths. I can tune out one frequency, but the switching grabs my attention and makes it impossible to ignore. I've ruled out water pipes, electric grid and any local industrial processes as I hear the exact same hum at my house in Hawaii as well as at my sister's house in Texas which have completely different septic, electrical systems and I've ruled out that I'm just nuts because she hears it too and it's driving her crazy. I hear it outside as well and even when the power was out in my entire side of the island once. Any suggestions? For a short time there was a third tone that seemed to be around 40hz, but was oscillating slightly as if it were two tones together. I used a tone generator to match the frequencies to what I was hearing, like tuning a guitar by ear. 63hz/85hz. There is an 85hz tone video on youtube where someone commented they hear that in their home. Between me, my sister and the random youtube commenter, I know I'm not alone.
 
https://thehum.info/ describes two reasons - one internal similar to tinnitus but at a low frequency, and one where people have unusually sensitive hearing so hear something external that doesn't bother most people. There are links to ways you can check which it is, and perhaps track down an external source. This can be done with free apps on a phone.
 
Different problem, hope it is OK to post here. I have 120Hz hum from a corner in a room, barely audible but I want to get rid of it. Checking breakers I found the circuit at fault, and that circuit is for two rooms next to the room where I hear the hum. So whatever is vibrating must be resonating with something that carries it over to the room where I hear it. Don't hear it in the rooms with the circuit at fault. I thought it must be the doorbell transformer, which does hum, but different circuit so no. I have unplugged everything on the circuit in question but no luck finding anything. I have tried to pinpoint a location in the basement where the wiring runs to these rooms but no luck. Maybe I need a funnel around my mic to focus better. Any other ideas?
 
I only have LED in those rooms, and lights were switched off. But are you saying the wall switch might not be turning all the way off?
edit: now I remember long ago my brother-in-law re-wired lighting on the problem circuit for multiple way switches. Maybe I should be suspect...

But also the lights themselves don't seem to hum.
 
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No it was the CFL bulb was dark, so they though it was turned-off.

What about high-tech wall switches or outlets?

What about wall-worts?
 
No it was the CFL bulb was dark, so they though it was turned-off.

What about high-tech wall switches or outlets?

What about wall-worts?
Nothing high tech, no dimmers or anything. I unplugged wall-worts and everything else that was plugged in in those rooms. I am going to listen more carefully in the basement and see if I can find what is carrying the noise. Even if I can't find the source maybe I can dampen the vibration.

edit: I found the culprit, a zone valve transformer. I didn't think this was on that circuit. So not much of a mystery, jusut a case of an old house where it is hard to make sense of the wiring. Put a clamp on the transformer now which knocked the 120Hz hum down about 10dB lower. Maybe I will try a new transformer but this is probably good enough.
 
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