There was recently a topic from Anon about 240Hz troubles in his home. I'd like to request for ideas & knowledge as well, currently having troubles at my location. European electricity flows at 50Hz. Its 1st harmonic is clearly present.What remains some enigma is the pipe of noise flooding and centered around 25Hz. What can it be ? This sh1t is highly detrimental to nervous system.I found this lecture of interest.https://federalpacific.com/wp-content/uploads/2019/01/2016-FP-Understanding-Transformer-Noise.pdf
forgot the scales on my snapshot.
Just to represent the intensity of those ULF noises, here is a capture when I'm using a 750W drill in the right next room.
- The microphone is certified tested by a Lab, Earthwork Audio M23R- Levels balance is calibrated with picrel- Soundcard is Sound Devices Mix Pre3 II
subharmonics
>>2711357I've been hearing some odd sounds recently. not sure when it started, but maybe a week or 2 ago.sound seems to be somewhat random between about 50hz and 200hz. not really sure because I don't have a sensitive enough mic. very very quiet but can hear it through my pillow at night.Live in the US so power is 60hz. sound seems to come from everywhere inside my house but only at night.can hear it while walking around inside the house. open a window and stick my head out. sound is not there. can hear it if I place my ear against a wall (sheet rock).it's not my Air conditioners.not air handler.not my subwoofer.not water pipe noise.not aircraft.not cars.not neighbors.not fridge or freezer.we did have a vibrating sound that we finally identified as the pressure regulator on our drip irrigation system, but that only runs between 6am and 8am on specific days.
>>2711416>subhamonicsI also thought about it. Now, I'd like to understand how subharmonics can emerge from the power transformer, filling the whole neighborhood (for having experienced my MixPre3 on mobile recordings' sessions).
>What can it be ?
>>2711431>it's not my Air conditioners.>not air handler.>not my subwoofer.>not water pipe noise.>not aircraft.>not cars.>not neighbors.>not fridge or freezer.I've like you checked everything and even listed footprints of every noise frequencies produced by my devices in the house. An example on this search by instance, I found the fridge was producing a particular pattern in noise, seismic vibrations, and radiofrequencies. But it's definitly not that one, having also shut it down during nights.>>2711494>I'd like to understand how subharmonics can emerge from the power transformermaybe this swedish knows.https://www.sciencedirect.com/science/article/abs/pii/S0378779620301310
>>2711499it would be a huge one then. The hospital is 300m away.There is also 2 pension house for elders with big vent system in the 500m circle.I monitored some smaller pumps and they mostly push at 70Hz and 125Hz.Keeping the power transformer possibly responsible of the troubles, it is located under some 300 square meters 19th century Stone & Metal food market. They did renovation before the troubles happened. Its some metal roof, but they added wood to its roof. And sound likes wood.So I did rent a flat 2km away in the city to test how it was. And awake with same troubles filling the rooms late in the night. Away from the hospital, the pensions houses, the food market.What else went new by the time I experienced that at first ? PLC Grid smartmeters in the city, the signal being spread from the main power transformer feeding the whole county, and on the neighborhood's power transformers, then getting datas in houses.I make this assertion since after checking for many possibilities it's the only remaining as viable. But I may be wrong.I'd like to inject my own signal in the grid to counter-experience. Some frequency generator, but how to inject the generated signal. Any DIY PLC howto existing ?It shoud be quite doable as the grid maintainer claims it's only 2W of power they inject.On PLC, that lecture from the earlier pointed Doctor is worth reading.https://www.diva-portal.org/smash/get/diva2:990228/FULLTEXT01.pdf
>>2711431Can it be seen as a line in spectroid?
>>2711512>Keeping the power transformer possibly responsible of the troublesI also made empirical tests close to some Frost Truck, spilling 90dBA at 53Hz. What I experience in the house is by far deeper but quite close in feelings hammering the body.*synical* I wonder why Israel doesn't torture Gaza with this.
>>2711515You saw the FFT, it's mostly straight.Then there is slight distortion in the lowest frequencies, stuttering due to load ?
My retarded neighbors dishwasher looks like this
>>2711520I use spectroid from time to time, it's nice for instant experiments throughout city and countryside, but on a 24/7 monitoring it's dead end. It also depends heavily on your phone's microphone specs. Good if you have a quality mic.. But having interesting to that topic I also found that vast majority of phones manufacturers doesn't provide response frequencies of their mic.
>>2711431last night I woke up at 01:00 I could hear the humming noise, so I broker out my phone and recorded this near my upstairs fridge. it is not the sound I am hearing as this is clearly audible.
>>2711789I also went in to a small closet where I could shut the door, and not record my cat purring (he was following me around).this is what I got.not sure what the 121hz line is, I used a tone generator to make a 121hz tone and it sounds too high pitched to be the sound I hear, but the weird thing is I could not hear the 121hz sound.I also think it's off slightly and should be 120hz.I could hear the sound when I woke up at 05:00 and again when I got up at 06:40.it is 08:00 and I cannot hear it now. when the wife leaves and the house is quiet again I will do more monitoring.
>>2711431>>2711789>>2711797this is meI remembered I have a Zoom H1 recorder. so I pulled that out, set it to wav file, auto level, and no low cut. after the wife left this morning I shut off the Air conditioners, and went around the house letting the mic sit for 1 minute and not moving. I did 7 areas but the first one was the most interesting.this was in my upstairs bathroom (no door) a small fridge is about 10 feet away. this one had the highest levels of low frequency sound of all the rooms I tested. I was as far from the opening as I could be. I could not hear anything unusual at this time.
>>2711873in contrast this one was 5 feet outside the bathroom and 3 feet from the small fridge.
>>2711875this is my server room (large closet) 15 feet from fridge and bathroom.
>>2711876downstairs laundry room with freezer running at the time.
Try recording near the breaker box, mine occasionally makes a weird noise when the dryer first kicks on.
>>2711357get tested for tinnitus, it's more than the high pitched eeeee noise that everyone memes on. the low rumble can happen from time to time and it will drive you nuts. ambient noise like ceiling fans help with reducing the low pitched noises. but I'm also a fed too, and you're close to getting swatted for researching into what you're not supposed to.
>>2711910>you're close to getting swatted for researching into what you're not supposed to.TACAMO? like no one's heard of that.
Use a soundproof wall or make one around things which generate the noise
>>2711877this was interesting, I though I could hear the noise a little bit ago and made a short recording at my desk. AC not running.the noise is between 100 and 150hz and fades in and out.
Switch off the main breaker and record that.My basement has some kind of ground hum, maybe it's because of the highway about a mile away.
>>2711942not sure who you are responding to, but that's a no go for me, I have 3 computers, 1 server, 2 NAS boxes, and several surveillance cameras. shutting all that down, is a pain in the ass.
>>2711789There is clearly 2 big pipes of low freq noise on this trace.when you need it, with 2 thumbs, you can zoom in and slide to a thiner freqencies interval.>>2711797It's more 120Hz + delta(microphone quality)So Power transformer noise if you live in America or Japan.
>>2711910>but I'm also a fed too, and you're close to getting swatted for researching into what you're not supposed to.Well, if you are FED, help me then, sending me some devices, you'd know the one or two I'd need to have in my shack to experiment and reproduce from labtests I guess. No, I'm researching for my own peace, just like it was before in my home, sleep well, code well, work well. I don't feel confident about all the conspiracy crazy stories some people I cross, claiming about impacts in their life are mesmerized with. Instead, I bet it's more an accumulation of negligence by mongrels who don't master the important points of the technology they put on the market but want to get a good position and make consequent money with their job.But I also understand what can be negligence one day, can become a widespread city weapon to morrow.
For the past weeks I've heard a low sound only on the north side of my house 24/7. Kept me awake for the duration. I was going insane. Told some word buddies about it and when I came home the tone was gone. I slept so good last night and feel like a new person.
>>2712050I couldn't hear it outside
>>2712052>I couldn't hear it outsideIs there PLC set up by your power company to monitor the grid ?>>2711910>ambient noise like ceiling fans help with reducing the low pitched noises.I'm in the process of trying that, having made all the setup for installing ducts and fans in my ceilings.This morning I feel a 0.83Hz rumble. This is a regular pattern that blooms from time to time in the env. Due to its morning hours I think it's related to human activities and power consumption.Using HSTempo Android app found on F-Droid, tapping when I feel the intensity is at its peak. Converting then the BPM to F.It's been many months I reproduce the experiment and always land on that particular extremely low frequency.>>2711947I have roughly the same setup. RAID boxes are sitting on rubber tiles. There is no particular loads on the boxes. They are plugged behind UPS then a low pass filter which you can find on some electronic devices, like desoldering pumps
>>2711933me again. last night I got up around 03:30 made this recording in my bedroom.https://youtu.be/oqUC-KU_pR8I tried making a webm but to comply with the absurd upload rules here it looked like garbage.not sure what it is showing. recorder was resting on a night stand next to an outside wall south side of house. sounds are at:20-70hz120hz240hz366hz (odd)450hzand 600hz.nearest transformer is an on the ground one one house south of me then 2 houses to the west and east across streets then 1 4 houses north.as stated before I only hear the rumbling at night, it is louder in one ear than the other, it slowly fades as the sun comes up and I really cannot hear it at all after about 10am even in a totally quiet house.it doesn't cause me problems sleeping, which is surprising because I have misophonia and certain sounds make me angry.
>>2711494If you have two mains powered fans driven by synchronous motors, they should in theory be in-phase. If one of them has a high load, bruken bearings or other issues that leads to phase slippage, they will go in and out of consgtructive and destructive interference. You can hear this pattern from multi propeller aircrafts. What you hear is the difference in frequency, say 400 Hz ved 399.5 Hz. If this 0.5 Hz beat reaches a non-linear material you get stronger mixing, and worse, if this is close to the resonance of a larger structure, you get big time amplification, just like the sound box of an acoustic guitar. Just keep in mind that the resonator can be a bit away from the two main sound sources.
>>2711921These don't work at all for low pitch noise.
>>2712279I agree it's some very aggressive sound to listen with headphones.I did experiments to reproduce the frequencies you listed. if you are curious here is the bash script I once built from SoX manual#!/bin/bashsize=3840x2160file=electric_tones_ltscale="log"fscale=logSYSID="20 70 120 240 366 450 600"FREQS="sin ${SYSID// / sin }"sox -V -r 48000 -n -c 1 ${file}.wav synth 600 $FREQS channels 1ffmpeg -y -i ${file}.wav \ -lavfi "showspectrumpic=s=${size}:mode=separate:fscale=${scale}:fscale=${fscale}${freq}" out_${file}.pnggthumb out_${file}.pngthe wav generated sounds close to your recording
>>2712529I don't have access to linux so I found a website that lets me mix and match multiple tones.https://onlinetonegenerator.com/multiple-tone-generator.htmlI found that 25,50,and 60hz sine waves all playing at once really comes close to what I hear. the only thing it lacks is how the sound seems to warble and vary over time.https://youtu.be/8kvuGVUS8Tkthis is what it sounds like (at long as youtubes compression doesn't change it.
>>2711357What software and equipment is this?
>>2712572>What software ffmpeg>and equipment is this?>>2711371
>>2712553>I found that 25,50,and 60hzIf we take Electrical trouble as an hypothesis, you are not supposed to get both 50 & 60Hz.{25, 50, 100} on EU grid, {30, 60, 120} on the US grid. May subharmonics' blooming be linked to this question ?
>>2712695>you are not supposed to get both 50 & 60Hz.Not expected, no. However, people can have their own inverters for running imported equipment, typically larger and specialised equipment.
>>2712706True, but I think it remains a niche situation.Frost chambers, solar panel inverters, electric car charging stations maybe ?
>>2712695don't all kinds of different devices plugged in to outlets produce harmonics on the entire stretch of wire, depending on how the device uses electricity? And practically all modern devices modify from the 60hz or whatever coming in.
>>2712695I'm not going on an assumption that the problem is caused by the electrical grid, if it was I would expect it to be louder during the day (and summer) when it would be used more. mine only started a couple weeks ago.50hz etc. is more of a guess on my part trying to read the spectrum of low frequency hash is difficult.I use goldwave for my waterfall charts used in the videos.last night the noise did not start till some time after I went to sleep at around 21:30 it was loudest at around 01:00 and as usual has faded and is gone at this time. oddly while wandering the house and recording, I noted that when the upstairs fridge door was left partly open it cause some kind of harmonic with the compressor and generated a very low tone, which went away when the door was fully closed.I'm thinking some kind of construction? though I never hear backup alarms. the sound kind of fades in and out sometimes quickly over a second or 2, sometimes over a minute.I made a recording last night outside my upstairs window which showed nothing conclusive except the 120hz sawtooth noise was still showing but very quiet.I think the 120hz (and harmonics) are my various power supplies, UPS's, and computer equipment.
>>2712750>Frost chambersnot sure what that is, but I live in a desert.>solar panel invertersyeah there are 3 or 4 within 2 houses of me in every direction.>electric car charging stationsnone of my neighbors has an electric car that I know of.>>2712761>And practically all modern devices modify from the 60hz or whatever coming in.yes but those frequencies are in the 100,000hz region usually.
>>2712828I checked my cities website for construction projects, the only ones within a mile of me started yesterday and today. there are some that started in mid october but they are 2 mile away. all are road construction.I checked google maps and there is a rock crushing business 2.79 miles from me, and 2 quarries 6 miles from me. don't know what their hours are. I've lived at this house for a little over 2 years and not heard anything before.we have noise ordinances here so between 23:00 and 07:00 you can't make noise without a permit.
>>2712832What about windmill farms? At a glance, the sound the turbines produce sits @ 40-50 htz (the blade noise is higher, but apparently doesn't carry as far).
>>2712837no windmill farms within 200 miles of me.
>>2712837nearest power generating station is a nuclear power plant 45 miles away.nearest substation is 5 miles away. no above ground power lines or high tension lines within 2 miles of my house.
>>2712845so the house is quiet right now, and I can barely hear it, I guess it's not gone during the day but it is a lot quieter.I have my recorder hooked directly to my computer and monitoring it in goldwave. trying to see if the "throbbing" matches what the spectrogram shows.either the program or my recorder or whatever is not very granular at low frequencies. everything from 20-35hz is grouped together. 40-50hz, 50-60, then at 70 it starts to show individual freqs.
>>2712946If you use 3 or more microphones, placed just less then half a wavelength apart in a circle, you can use direction finding methods to find the bearing to the noise source. It is best to record all microphones and analyse in post processing.
>>2712692Didn't know ffmpeg could do that. As much as I've seen it on /g/, I've never given it a second thought.
>>2712958>placed just less then half a wavelength apart in a circlehalf a wavelength for 60hz is 8,196,425.5 feet. not really feasible.
>>2711933>the noise is between 100 and 150hz and fades in and out.I figured this one out after reading some stuff online, it's the 2 hard drives in the mirror on my computer as the motors go in and out of sync.
>>2713238So place them 1 m apart. The "just less then" was to indicate that is the wavelength was 10 m, a 5 m separation would not do, it has to be less to avoid Nyquist problems.So for 60 Hz the wavelength is 343 m/s / 60 Hz is 5.7 m so 2.5 m is fine.>8,196,425.5 feet.What did you think the speed of sound was? Also, this is year 2023, how about going metric?
>>2713343>how about going metric?conversion sites exist
>>2713132>Didn't know ffmpeg could do that. As much as I've seen it on /g/, I've never given it a second thought.You can produce FFT, and limit the spectrum to some particular frequencies interval, very handy to setup 24/7 monitoring under cronjobs.There is also realtime waterfall options.
General rule: check your ground. Your main panel should be earth grounded, with a solid bond to neutral. Only bonded at the main panel, not any sub-panels. Check the condition of the ground rod clamp, rod(s). Your ground may go from one rod to another within 6ft, but there's only one wire between the clamp or clamps, and the main panel.Many houses have a shitty ground, or a bad bond to neutral, or multiple places where ground is bonded to neutral. Electronic equipment, power supplies, can intentionally leak a tiny amount of current to ground - not enough to trip a GFCI unless it's like a whole computer lab - but enough to cause issues if the ground is no good.I'm suspecting that's where at least some of these audible harmonics are coming from.
>>2713501I recently (last year) had work done and the electrician said that all my panels were correct. my house was built in 1993.also today the hum is completely gone. we'll see if it happens at night. I suspect something that is only used on weekdays.
>>271350150Hz-Anon here, I'm gonna buy a meter to check all plugs in the house, request a contractor to test main ground.I've already doubled the main house ground for just being sure. 2 copper rods are in the basement, from ealier setups by electricians years ago. 2 because we issued an official test before renting, and it was at 110 ohm. Framing law says: remain <100ohm.A second rod was set. It went down to 84 ohm.Since, I've put 2 more, 15m away in the garden, 3 meters each in a wet soil.Here, I can feel some humming even 300m away from the house. Once you vibrate at its frequency for long period, you sadly are attuned to detect it easily. I did tests going into some nearby shop, to the cobbler, at police station, at tobacco shop, an confirmed there low noise presence the same. Once I then went to a doctor 35km away. His office is located in area where there is a lot of E suckers. Banks, Telecom operator, Backer, FastFood, Pressing are there plugged.The noise sensation in his waiting room was as bad as what I can experience here. It was interesting to me somehow. I'm experiencing this in other areas, far away in the 400km round away. So I plan to travel to confirm it's not something I can experience in just a different country, not enslaved to the same plc system.Speaking of transformers themselves, I have 3 located 100m way round. 4+ in the 300m way round. As I don't now much about power transformer, like any common people, I'm wondering a bit about them. Do they share some barycentric equilibrium each-others? Do they communicate noise? more noise under the PLC subservience?There is days when there is no particular sound, then it hammers again. This summer, during 4 weeks: total stop, whereas located on the coastline, it's a very busy area by that period. Let's suppose it's about frost-pumps and vents, it should have been noisier. It was opposite: No trouble from 11th of July to 19th of August, except a few minutes of minor noises at morning.
>>2713732Since the PLC is located on a 5kHz-100kHz bandwidth, I've started monitoring RF signals around.Here is the typical noise I can see like every day on the SDR, evolving more or less, with more or less ground noise on its spectrum.
>>2713736I recorded yesterday unusual waterfalls, things I've rarely seen. This one at about 10:15AM
>>2713738Then 39 minutes later a very distinctive pattern the same, on which I'm wondering if it's not someone transmitting quality line tests. I'm making this assertion since the noises in presence 99% of the time are simply not existing during what I qualify as "test".
In the begining I bought a cheap chinese antenna on Aliexpress, then I finally spend 500€ in a high quality antenna. I know Deutsch Telekom use it on its tower in Bohn. Sounds like a good sign of acknowledgment to me. So my antenna points a 3phase cable from the street, 1m close.
What I'd like to do next, is inject noise at certain frequencies into the grid, to monitor how it behaves with sound recordings.I already have a good signal generator, and found some documents on DIY PLC systems.
>>2713550>we'll see if it happens at night.yeah it came back sometime after 21:30. and seems to be gone or faded at 07:00.
>>2713732https://en.wikipedia.org/wiki/The_Hum
>>2713738https://www.sigidwiki.com/wiki/Signal_Identification_Guide
>>2713738That repeating pattern is a clear indication of massive overload in the frontend.>>2713741Have you tried direction finding? If you ise teh Kiwisdr interface there is a RDF option.
>>2713799Thanks Anon, I will document and experiment this. Need some Lithium-Ion as well to go on remote-tracking.
>>2713794That was a typically weak, limp-wristed wikipedia article. Talks about fish being a cause, while avoiding deeper issues. How predictable.The David Deming citation is worth looking into; at least you have a name.Here's one top pick:1) Underground tunneling or other operations within those underground areas.* It's been known since the 50's that there are periodic events of pole rotation. Maynard E White's core samples and reports show this, with the mainstream science then being derailed with a CIA-backed book on the subject, and further financing into the area being cut. It's also been known since the 50's that the Air Force has been tunnelling, building underground bases. Why would the AF be heading-up such activities? Good question. As above, so below.Before I get the usual skitzo replies from non-performers who dwell in their mother's basement, the AF tunnelling equipment was pictured in a mainstream publication at the time. And Maynard E White's expedition would be otherwise unknown in public, except for his descendant Ken White's acquisition of copies of documentation he received from Maynard. 'World In Peril: The Story Behind The Discovery of Imminent Global Change' is $269 on Amazon for the hardcover, published as a 2nd Edition in 1994. Libgen probably has a scanned copy. >>2713732* The tunnelling or activities underground, would explain how, 400km away, you can hear or sense the same noise and, possibly, pick it up on a suitable meter as you have done locally. People that have other sensitivities, such as those who find water, and know where to dig a well (intuitively), are another example of real-world application of our First Sense, sometimes erroneously called 'The '6th Sense'. Rather than being a defect, think of it as the Canary In The Coalmine, and how silly and dangerous (for them) when miners laugh at you for falling over.Please, continue your investigations.
>>2714255>It's been known since the 50's that there are periodic events of pole rotation.How can this relate to low frequency noise?
>>2714324Sounds produced from digging underground, or other operations deep underground (machinery), can propagate over long distances, and cannot be found on the surface. If someone is thinking 2-dimensionally and not accounting for the vast possibility of depth, they are not going to find such a harmonic or noise produced, that emanates over such a large area (400km).
>>2714324Because in the case of a cyclical cataclysm, you want underground facilities.Every native american (or indigenous or whatever you like to call them) tribe has a legend of coming out of the ground. E.g. Grand Canyon. There's no way an astute anthropologist working with geologic surveyors, and related scientists, would not figure out what that meant. Particularly when combined with ice core surveys showing a 12,000 yr cycle of sudden freezing (within a day) of tropical material.There is the famous Birdseye case (same as Birdseye Foods founder) who witnessed a mammoth frozen in siberia, so fast it's hips were crushed by the weight of the ice, and with fresh vegetation in it's stomach.
>>2714324god dammit you engaged him.
>>2714340>Sounds produced from digging undergroundThat is still not a pole rotation.>>2714343>tribe has a legend of coming out of the groundAre any such tribes in the roomwith you now?>>2714382We are now secured cheap bumps until OP comes to the bottom of the mystery - or the poles are rotated.
>>2714255it's an interesting story and understand well it is a possibility. I could expose why I doubt this is the case by my side, but who knows. Many times I've already come back in my judgement and requested those I tjought to be potential noise source for checks. All did except the grid company. The same that refuse to tell the exact date and hour they did fire up their communication live in thé city. An exact date I know in my inner feelings. I remain very patien facing those bastards, a bit too much concerning health developments, but it will end in courthouse.I still sometimes come back to fundamental doubt. As I said, I will check again all my E circuitry in the house to be 99% sure. Maybe there is a ground loop after all. I got many surge protections to filtrer out DC. Pro: I'm becoming skilled in my diy electricity, but who knows, there might be a fishgusting and stupid error somewhere. An assertion that may apply also to the grid maintainer.Concerning the itching-vibrating sensation in the ambient acoustic. I record it phasing both on microphone and sismograph, with distant devices locations.fact: I was this morning experiencing it in a lectures' room at my cityhall. A power transformer is next to the building.To conclude I had a very particular experience the night of the turkish quakes in feb. I was definitly feeling the stress, much acquainted and attuned to endurre low freq. As it was very particular but different from daily events I gave an eye to the sismograph and quite instantly understood a major quake was happening. And all the simographs I then scanned had the same magnificent trace. I'm maybe 2500km away. The next morning an American Guy told me his dog barked the whole night, and I watched his device, even that distant, the quake was well present.Back to your stories and my doubt, the recent events in Iceland made me think, And if.... fuck...maybe it's Elon boring machine company, tunneling in the Alpen, which I seriously doubt.
what remains the most problematic in those problems is general healthness. As son as you are falling into detrimental sleeps cycle, everything becomes harder to achieve in work. requires more mental effort.second things is those kind of topics are mostly negleted by public offices and most of public servants unablr to understand those concepts. As soon as you pronounce the word Dave, they are prone to speak about 5G in reply.last point, it's costly. I see some gorgeous impedance monitor, it's 3500€.. No help from state on this. and I'm not the loveablle social guy for sucking on crowfunding. So I spend what's left extra from salary within a timescale.and spare for courthouse too.I know a complete and discrete way for tottures. Freaks.
>>2714678>DaveWave ! bitching Android rewriter
Sounds like the Havana syndrome. Any weird vans parked outside your residence or have you upset the Russians?
>>2714691who are you talking to, there are about 4 people who posted issues?
>>2711494>>2712318Phase slippage on synchronous motors doesn't sound like it would be a gradual thing at all, the rotor should be completely locked to the rotating magnetic field. If there's ever enough slippage to make it spin at a lower frequency than mains, that would mean it's suddenly skipped an entire step, and it wouldn't have such a close frequency to mains if it's skipping steps. Definitely possible on async motors though, even without dodgy bearings, all you need is a bit more or less resistance to flow. But phase slippage isn't going to cause an exact fraction of the mains frequency (i.e. a subharmonic) without lucky chance, and that frequency wouldn't be expected not to wander about.Rather, I believe subharmonics could come from two sources:Firstly, a synchronous motor that undergoes one revolution every two mains frequency cycles (or maybe some multiple of two). This is quite easy to get from a variety of numbers of slots and poles. Well I've heard that it's only a function of pole count but that doesn't really make sense to me. Idk, still works as a explanation.Secondly, a transformer or other magnetic structure with a natural mechanical resonance near 25Hz. Especially a big iron distribution transformer.>>2712205Is that a filter with two common mode suppression chokes, four normal chokes, or half-and-half?
>>2714859>Phase slippage on synchronous motorsCheck the following link, and disregard the comments from our Indian friends:https://www.quora.com/What-is-the-slip-speed-of-a-synchronous-machineThe term used is pole-slipping.>phase slippage isn't going to cause an exact fraction of the mains frequencyTrue, there is a random component here, and the hum I have here (I am not OP) has a clear variation 0.5 - 3 Hz.
>>2713741Cool.
>>2714859Maybe it is useful: the seismograph records a constant sinusoidal wavelet around 25Hz. As I earlier said, the one that shines on the FFT audio takes.I bought an university book about power transformers, maybe I will get enough knowledge to have a better understanding of what you details there. I see an overview, but it remains unclear being not taught to those very technical devices. Except having done theory and vector maths on it long ago.
It would be interesting to build a copper tile on which I throw an electrical sinewave at those frequencies to check if it amplifies the body feelings the same, in the respect of safety levels for human body. Then position myself on that tile.11/01/2023 same wavelet, same freq.
Like in Audio signal, all other ambiant noises are the big problem concerning a seismograph and isolating the particular noise's device you want to track. Night is a particular period where everything's quite in the city except for backers at work.Zooming out on the graph seems to make more subharmonics slightly appear, 12.5Hz (4), 7.14Hz (7), but also a fingerprint near 36Hz. 25Hz fingerprint is evolving, raising from 9 to 10, then stops from 11:30 to 12:30.
Tuning a bit the FFT filter. that part in green is the « 6 February 2023, at 04:17 TRT, Mw 7.8 earthquake struck southern and central Turkey and northern and western Syria ».Sad event which finally gives a feeling of the strength of the ground noises in my area. 2 walls have already crumbled through the year, one 100m away, a power transformer 800m away exploded.Requested, mayor remains silent to those alerting events. Good 6G6 boy.
>>2715058Look out for coupling in from RF, specifically this one:https://en.wikipedia.org/wiki/Schumann_resonances
>>2712529>ffmpeg -y -i ${file}.wav \ -lavfi "showspectrumpic=s=${size}:mode=separate:fscale=${scale}:fscale=${fscale}${freq}" out_${file}.pngI sort of figured out how to generate a file from ffmpeg using the one line from the script.so then I ran the recording I mentioned here >2711873this is that output, also the hum I hear is still present but only at night sometime after 21:30 and sometime around sunrise.
>>2715145it's the call to Sox that produces the sound file, but glad you reached to build it. I agree it's some very stressful noise
>>2715145last night when I got up about 03:47 I started recording in my bedroom with the mic sitting on a piece of clothing and me not on the room. here is a snippet of what I recorded.low frequency pulse about every .5 seconds peaks at about 35hz between 0 and 70hzRises and false about every 00:01:34each "throb" is about 37 seconds long spaced with about 1 minute of less throb. thing is, it doesn't sound like that to me.
>>2715353this is what the waveform looks like with volume set to full dynamic range
>>2714539> does not explain pole rotationNGMI
Not OP, but here is a spectrum with two fans that are close in RPM but are not exact. The signal at 120 Hz is not the problem, the two below are.
>>2715353I see it way much saturated concerning input levels. If you have possibility you must lower your input levels on the mixer.Good example to balance your input is to set the microphone stable in the room you will record, window opened during daylight, catch and make your levels able to listen birds whistling in your headphones without going excessive on levels.
>>2714539> or the poles are rotated.whatever it is, I want it to stop now. I cross often people in similar problems going on conspiracy theories, but that's not my kind of brewery. If it shakes and it sounds, it's recordable, trackable. The SDR radio triangulation seems a good way to go. And with same kind of battery packs, aided by a monitoring laptop, organise one raspishake for mobile sensing.
>>2715521that spectrum was made AFTER I boosted the audio to full dynamic range so you could see the pulses more clearly, this is without boosting.
>>2715591and here is a 1 minute section from the 0003
Thoughts on what might be causing this noise in my house?
>>2715532> conspiracy theoriesIt's science. Go look it up. But since you're too lazy to do that, NGMI.
>>2715629I don't think you read his post.
>>2712553ok while messing around on that site there was a binural beats tab and i really liked the sound of 304hz left and 307hz rigjht then i looked up online binural beats are used for meditation so do you think there are some good frequencies for the nervous system
>>2715652no idea what you are talking about.
>>2715597i think your house is hiding your tamagotchi
>>2715652>so do you think there are some good frequencies for the nervous systemI use to listen them on certain nights hammered by the noise, it allows you to change your mind by superimposing something else to concentrate on.I've learned Tibetan music is based on the use of some particular frequencies even down to the way they sing.https://www.youtube.com/@nrg8/videosI heard some medicine chairs use Ultrasounds to cure some pathologies. On the other hand, ultrasounds can also be used as a wave carrier, transports hammering signals at very low freq. This kind of use is a typical directed non lethal weaponery, studied by some police/army industries. Autralian police already used wave canons on protesters.
>>2715838>medicine chairs use Ultrasounds to cure some pathologiesno they dont "HEAL" they destroy tissue that is been affected, in some cases this tissue is a lot infected so getting rid of it will cause increase of overall health of the patient.but in reality Ultrasounds are most often used to break stones, be it kidney stones or gallblader stones.since those stones are often from one single chemical component, they resonance with the ultrasonic and break, but the problem is that the tissue around even if is not of the same resonance, it suffers damage also, this is why others techniques were developed in case the stones are very hard and big and more ultrasonic energy would be needed but in this case will not be beneficial because it would kill the tissue of the organ around completely.i hope i helped you guys understood it.
>>2716140>i hope i helped you guys understood it.Yep, pertinent points, able to better understand how it's used in medicine, thanks.Back to my own home, this is why, beyond the nervous hassle to the body and psychological torture of those repetitive troubles, more a "Havana Syndrome"-likealike, I'm fearful about the long term potential troubles on the stability of my building. Low noises on the right-bad frequency > resonance > crumble.
>>2716880First wave at about 25Hz had already started at 23:31 UTC, then the second wave launches (earlier picture). It presents on both launches an analog starting cycle clearly identifiable.The dots pattern recorded and shown here presents quite well that reality of a wobbling sound pulsing around 25Hz. facts: Laws related to noise are outdated in my country , do not scout below 70Hz (dbA scale), and do not take "psychic-modeling" patterns in account. It's a wide door open to FFA.
This one lets its fingerprint in the records from time to time. I interpret it more as a triphase motor starting from a nearby device, maybe a backer in the neighborhood.It's an instant start, and vanish. The problem is on >>2716893 >>2716880 pictures.Experiment: >wearing Heaphones, >Reproducing a 25Hz signal>wobbling it at 0.83Hz >same mood.Problem: low frequencies pass through everything. A Portuguese lab had fun calculating that 500m from a wind turbine, it would take 330m of wall thickness to cut its through frequencies.Only solution: find the source, eradicate the source by any means.
>>2716898It's so low in frequencies and powerful, I doubt a backer has any machinery able to produce such a wave.
>>2716880Audio trace here.It's not visually synced but chronologically it is.
>>2716961and the follow up recording.Since the 35-50€ environment microphones are of really low quality, before ordering a second Earthworks Audio mic, the 1500€ model, I will test how sound captures behave in spectral response with the 225€ models from BeyerDynamics and Sennheiser. They are told from specs to go down to 20Hz. Less than Earthworks who records down to 3Hz, with the bottleneck of the soundcard noticing 10Hz as a limit on the manual.It should be ok since what hassle there is 20Hz<H<120Hz.
Realigning my different timing figures (10min cronjobs on Audio vs constant pipe on the sismograph), I see the records are in perfect synchronicity, which is normal, but proofs also the microphone is recording with accuracy in the very low freqs.
>>2716893>>2716898>>2716931>>2716962>>2716964your posts are a dichotomy of apparent knowledge, and lack of explanation.It's difficult to tell who you are talking to, or if you are just posting information.you mention things as if everyone should know what they are. this indicates a high amount of intelligence but a lack of understanding that not everyone knows the things you know.FFA?backer?instant start and vanish?500m?also are you translating your posts? they seem like they are translated and as such a bit hard to follow.also you seem like you have a lot of money to contemplate spending $1500 on a microphone.not trolling, just trying to understand your posts.
Just to give an idea, this is the full linear spectrum by that time. A public servant following the regulatory laws for acoustic measurements, LAeq scale's shit, will never notice the slightest damage. In the meantime you can torture for free in that particular gap in law.
>>2711921this isn't soundproofing foamit's for getting rid of the echo
>>2716984Sorry to be obscure then, I try to get help from physicians able to exchange in the topic. And there is, having received good advices. I try to post a bit more on it to bring more examples.Sorry 4 my english, I'm translating with my head, and it's far from perfect. I'm sadly not super smart, else I would be in a Lab. I've been teatched to understand some particular things.>FFAFast Fourrier Transform>Baker, excuse my Deutsch>instant startan electromagnetic motor tends to have instant start>vanishdisapear>500m500 meters. ~185 yards ?Concerning the microphone, well it's an invest yes. Take in perspectives that expensive and semi-pro/pro devices can be easily sold back on ebay. With a discount it gets attractive for anyone wanting that shiny expensive mic.
>>2717000>Concerning the microphone, well it's an invest yes. Take in perspectives that expensive and semi-pro/pro devices can be easily sold back on ebay. With a discount it gets attractive for anyone wanting that shiny expensive mic.It's also the fact there is no help from public services, so I'm on my own to dig deeper, like 60Hz Anon. Trying to put forward good argues requires sadly to produce good quality measures with expensive stuff on the consumer market.
>>2717000hey don't sell yourself short. you seem to be quite knowledgeable in unix/linux. I have 25 years experience in computers going back to DOS days, but sadly I have no real unix knowledge.thanks for the clarifications. I was confused by FFA, I know what FFT is but was wondering if it was something similar.I understand metric, but was not sure if that was what you were using because the context was confused by the translation.I am curios how a baker would make low frequency sounds of high magnitude?also try posting a paragraph written in Dutch and running it through google translate, and we can see if that comes across better. or just post in dutch and I will run it through google.
>>2717000>>FFAFree For All, not FFT sorry..I meant using the FFA acronyms, that 0-150Hz is a part of the frequency spectrum where you can spill whatever you want and go mostly unseen to harm some people, by will or by simple negligence.
>>2717015yeah using acronyms is not a good idea, they have too many meanings.
>>2717009>I am curios how a baker would make low frequency sounds of high magnitude?I don't see how the same, it was an idea, thinking those works at night, but I hardly see them having machinery able to get that low.It's more a power transformer question, 3 lines evolving in synchronicity, a "zero sequence fault" ? This is where I'm lost to conclude. High Power Electrical engineering is a very narrow field.Yup, I'm fluent with Unix and have roughly the same amount of time on it than yours on Microsoft's side. I use it It since it's effective for producing a 24/7 survey chain.I also added humidity, ambiant pressure, temperatures, winds, sea levels monitoring in my chain but it doesn't give relevant results to focus on.
>>2717018wow, you must have some annoying noise you are dealing with. my low frequency warbling rumble that I hear at night is more of a curiosity than an annoyance.I have misophonia, but in this case it does not bother me. now put me in a room with someone who is loudly chewing food, and I will take a hostage.have you researched:The Taos hum?Very low, and Extremely low frequency communication? used to send messages to submarines.2 days ago I drove around my neighborhood about 1 mile in every direction from my house. I found an electrical substation I did not know about. visited the rock crushing plant (made recordings), and found a water treatment plant I did not know was there (also made recordings).my recordings showed no anomalous sounds.
>>2717021>Taos humI will read about>Very low, and Extremely low frequency communication? used to send messages to submarines.Yes but it does not match, since they communicate like this for far many years than this trouble emerging. There is a VLF antenna for such communications 150km away. They spread their signal in the atmosphere/ionosphere. It leads to Radio-HAM, an interesting topic allowing to understand things. The ARRL handbook is a solid base of many knowledges, I would like to recommend. That said on radio HAM, and since appart from the recorded audio noise, the ground is shaking - seismograph don't lie - I'm wondering about OFDM signals used by PLC, and potential spills of noises in the ground. How ? Unshielded cable carrying 20kV < v < 90kV and that disgusting signal (>>2713736 picrel).>a water treatment plantNoisy thing as well. Being a neighbor, besides the smell, can be hard for ears -> for nerves -> for brain.Once in the woods, next to a river, I found a water quality test station, also a noisy experience: It was a 6 square meters tiny house, with a small electrical transformer, a vent system to prevent things, and the real measurements system + its sucker plunged into water. 90dB straight for birds and boars.
>>2717033VLF (3-30khz) and ELF (3-30hz) is used because it can travel through the ground and underwater. ELF antennas can be 22.5 to 45 kilometers long. ELF transmission can travel around the earth several times before dissipating. they can also develop standing waves.I think china uses them, the US may still have some.There are also natural sources for them.
>>2717033>a water treatment plantall water treatment plants in my city are completely enclosed, so smells cannot get out. no open settling ponds.
Why do I refer to PLC that much ? problems started by then. This is a reality that I ignored at the beginning, not subscribing to expressing doubts about this technology. Using it myself, but at far higher frequencies. I was leaning toward other potential responsibilities. I canceled them little by little. Ultimately the more I dig, the more I come back to it. In my country, exploding power transformers has become a normality since. A reality in line with the conclusions a fair amount of researchers (I'd say roughly 20 university labs worldwide) have formulated. I possess all of their works. The missing point on the equation is that low freq noise.Or maybe it's something else entirely that I'm not able to see.
>>2717042imagine inside.30km away, I sometimes pass on the road next to a metanizer, it stinks nearby beyond a good distance.
Fucking humming sounds
>>2713501>Many houses have a shitty ground, or a bad bond to neutral, or multiple places where ground is bonded to neutral. Electronic equipment, power supplies, can intentionally leak a tiny amount of current to groundOk I checked ground with picrel => 34 ohm. It's a fair+ value.All my computers are on residual-current circuit breaker with a detection to break on DC leakages, tested that feature with success.I still have to check for Neutral.I realize I forgot a point of interest: There is a 3phase cable cut in 2 parts on the facade of the opposite building. Cable ends are in contact with a zinc's gutter.I witnesses 5 times those 6 months, when the day gets raining, that some electric arc bangs the street with noise and flash, just like in https://twitter.com/TheInsiderPaper/status/1729158638705725828This morning was some major bang, with colorful patterns lighting though the window.3 times I alerted the grid company, and they don't give a shit about. I will alert local authorities when they seems deaf and see if things gets better once fixed. I also have a 3phase cable, touching my own gutter, this one is uncut hopefully, but touching still => potentially coupling RF.
