I just realized that Rochelle salt is also known as Seignette salt. It is a laxative, but more importantly it is a piezoelectric material, once used in microphones and phonograph pickups. Perhaps this interesting phenomenon was the motivation of the use outside of the usual. But since it converts between mechanical an electrical energy, its particles must be moving... Moving particles create noise... or heat... Perhaps it dissipates unvanted electrical energy to heat?
Problem is if the whole house is already treated then there is no longer an untreated state to compare with. If starting out fresh, I would look at the power lines with a suitably input-protected wideband RF spectrum analyzer for changes in noise, any change, up or down. Measure before and after treatment. That includes overall noise floor too.
For measurements of the amplifier output, typical spectrum analysis may not show much if anything. If looking before and after treatment, could be some change in spectral line noise skirts though. A discussion and some FFT settings to look for that effect can be found at: https://www.diyaudio.com/community/threads/phase-noise-in-ds-dacs.387862/post-7063038 ...The remainder of the thread from that point on includes some possibly useful commentary.
For measurements of the amplifier output, typical spectrum analysis may not show much if anything. If looking before and after treatment, could be some change in spectral line noise skirts though. A discussion and some FFT settings to look for that effect can be found at: https://www.diyaudio.com/community/threads/phase-noise-in-ds-dacs.387862/post-7063038 ...The remainder of the thread from that point on includes some possibly useful commentary.
Markw4 "For measurements of the amplifier output, typical spectrum analysis may not show much if anything." Exactly. If there is nothing in the measurement there is nothing to hear. Loudspeakers require actual electrical power to be applied across the terminals to produce sound. If there's no differential electrical signal of significant power at the speaker terminals, there's no audible sound coming out. Measuring the voltage across a speaker terminal is a pretty easy thing to do. So if the amplifier isn't producing a voltage and current, the speaker won't produce a sound. Of course if you connect your equipment to the speaker terminals any sound in the room will produce a voltage as the speakers act as a microphone. So I guess a person could pretend that was coming from the AC line.
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Sorry but you are ignorant about typical FFT measurements. They don't show everything because they are designed not to. What they are good at is showing PSS phenomena (where PSS stands for Periodic Steady State). Thus there are other FFT techniques that can be used to look for non-PSS signals/effects. One such technique is at the link I posted.
I'm ignorant. OK. You don't need an FFT to look at noise. Look at the voltage vs. time. If there's a signal, you can use your eye balls to see it. Go record the voltage vs time for a long while. Capture the peaks. Go look at the signal around the time of the peaks. Maybe just figure it out for yourself, as I'm so ignorant. I don't have a problem with audible noise on my power supply rails. If you do, stop the "talk talk talk" and lets see some before and after measurements for these treatments that might be interesting for people with these noise susceptible power supplies. Any well designed audio equipment should be very immune to noise on the AC line to begin with. I guess if you bought some high priced boutique equipment it may have a very bad power supply design and audio circuitry with low power supply rejection. Electrical engineers have been quantifying this stuff for years without any problem. People with no formal training in the field are often unable to do the basics.
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If an amplifier's power supply circuit is well-designed, then a normal input voltage variation should not affect the DC rails. The same thing is true of noise on the AC lines. However, if you live in an area where electrical utility problems abound, one of the best solutions is using a Sola Constant Voltage Transformer. They are also known as Ferro-Resonant transformers. They have remarkable specs over a wide range of input voltages and offer better isolation than conventional ones due to the nature of their construction. They are also amazing at stopping surges and spikes. I have used them for over 20 years, protecting the sensitive electronics in sorting machines, which typically operate in some of the worst electrical environments possible and must accurately measure microvolt signals.
I live in a rural area where we get a fair number of power dropouts that last one or two seconds each, as well as thunderstorms. I am considering purchasing one for system protection and combining it with a seal-in relay circuit so the system will disconnect on the first power blip. It would require me to manually reset after the storm passes, which I consider preferable to getting my system trashed by a lightning surge.
I expect the salts mentioned above might get you in trouble with the electrical codes or homeowners insurance. It is hard for me to imagine how they would improve things.
I live in a rural area where we get a fair number of power dropouts that last one or two seconds each, as well as thunderstorms. I am considering purchasing one for system protection and combining it with a seal-in relay circuit so the system will disconnect on the first power blip. It would require me to manually reset after the storm passes, which I consider preferable to getting my system trashed by a lightning surge.
I expect the salts mentioned above might get you in trouble with the electrical codes or homeowners insurance. It is hard for me to imagine how they would improve things.
What if someone told you that your system could have a "veiled" or "grainy" sound, but you don't see it in your measurements? I mean, what would you even look for? HD? Something else?
What if that same person told you the way you know you had a problem is because of the change in sound after you remove the problem?
Okay.
Now, what if that same person was a well-respected expert on the subject with AES publications, invited talks before professional groups, etc.,?
What if that same person told you the way you know you had a problem is because of the change in sound after you remove the problem?
Okay.
Now, what if that same person was a well-respected expert on the subject with AES publications, invited talks before professional groups, etc.,?
People tell me all sorts of things. We had an audibly failing DAC in use at club meetings for months before I made some measurements and repaired it. Most people can't hear obvious flaws in a system. Experts have brought in systems that they proudly demonstrated that had a blown tweeter in them.
In college I worked in a store that sold stereo equipment. I learned from the other sales people how to sell you anything I wanted to. You would leave with the product that made the store the most money. You would be convinced that it sounded better than the low profit produce that we only had on the display for comparison. People are easy to fool. Go watch a Penn and Teller show.
A loudspeaker requires a current flow through it to produce a sound. This is basic high school level physics. Electrical current is trivial to measure in your home down to levels far far far below what is audible. This can be demonstrated with a signal generator driving a loud speaker. Keep turning it up until you hear something. You can do this at any frequency or with noise or anything you like. Below the level you can hear, it doesn't matter what is there.
An actual expert should be able to produce ample evidence. If not, how are they an "expert" rather than a con man. There are many thousands of publications that are absolute garbage. The most respected journals in the world have some percentage of garbage that sneaks through. Was the topic of this paper exactly the same as what we are discussing here? Almost anyone can serve in leadership and or present at the AES. https://www.aes-media.org/sections/pnw/pnwrecaps/2016/dana_speakers_oct2016/
Without evidence the unquestioned reliance of an "expert" is just a logical fallacy.
https://leanlogic.online/glossary/expertise-the-fallacy-of/#:~:text=Argument based on an uncritical,feel at challenging their expertise.
There is a whole industry set up to sell audiophiles fancy expensive stuff they can show off to their friends that makes them feel they are in on something special. That's great. It's art not science. Have fun. Enjoy collecting and displaying these works of art.
In college I worked in a store that sold stereo equipment. I learned from the other sales people how to sell you anything I wanted to. You would leave with the product that made the store the most money. You would be convinced that it sounded better than the low profit produce that we only had on the display for comparison. People are easy to fool. Go watch a Penn and Teller show.
A loudspeaker requires a current flow through it to produce a sound. This is basic high school level physics. Electrical current is trivial to measure in your home down to levels far far far below what is audible. This can be demonstrated with a signal generator driving a loud speaker. Keep turning it up until you hear something. You can do this at any frequency or with noise or anything you like. Below the level you can hear, it doesn't matter what is there.
An actual expert should be able to produce ample evidence. If not, how are they an "expert" rather than a con man. There are many thousands of publications that are absolute garbage. The most respected journals in the world have some percentage of garbage that sneaks through. Was the topic of this paper exactly the same as what we are discussing here? Almost anyone can serve in leadership and or present at the AES. https://www.aes-media.org/sections/pnw/pnwrecaps/2016/dana_speakers_oct2016/
Without evidence the unquestioned reliance of an "expert" is just a logical fallacy.
https://leanlogic.online/glossary/expertise-the-fallacy-of/#:~:text=Argument based on an uncritical,feel at challenging their expertise.
There is a whole industry set up to sell audiophiles fancy expensive stuff they can show off to their friends that makes them feel they are in on something special. That's great. It's art not science. Have fun. Enjoy collecting and displaying these works of art.
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Except hearing is highly nonlinear. Whatever you hear in that test is only applicable to that test (since linearity is a required condition for valid extrapolation to other situations).
Anayway, there is already a formal test of that type and a published threshold for it. Its called the "Absolute Limit of Hearing (for single tones)." Multi-tones are more complicated. Anyway, there is a published threshold for single tones. Now, do you know what a "threshold" number means?
Markw4: Ask the expert that called it "grainy and veiled" to define the noise and distortion pattern that you could add to your signal when ever you like to cause him to hear and produce this vague description. A true expert should be able to tell you what to put in that black box to transform clear and unveiled sound into grainy and veiled sound. If not, what good is this expert. He or she should be eager and able to produce a new AES paper describing the noise and transfer function for a box that reliably adds a veil and grain to music so the world can have a clear definition for these terms.
I've spent the last two months digging into the source of the sound of vinyl records. It turns out the majority of the "sound" comes from the path traced by the stylus not being the same as the path cut by the cutting head. The radius of the stylus is the source of a second harmonic distortion. The stylus traces a path that makes the peaks wider and the valleys narrower due to the stylus radius and the contact position on the stylus changing with the waveform slope. Only a zero radius stylus would perfectly follow the path cut by the cutting head. So of course records have a sound. You can read all about that at the https://pspatialaudio.com/index.htm website. It's just simple geometry that cause about 1% 2nd harmonic distortion for a 0.25 Mil stylus at 5 cm/s on a 1 kHz sine wave played on any turntable. Is that causing a grainy or veiled sound. Many folks swear that records are the opposite of grainy and veiled, yet the distortion is undeniably there due to the simple geometry.
I've spent the last two months digging into the source of the sound of vinyl records. It turns out the majority of the "sound" comes from the path traced by the stylus not being the same as the path cut by the cutting head. The radius of the stylus is the source of a second harmonic distortion. The stylus traces a path that makes the peaks wider and the valleys narrower due to the stylus radius and the contact position on the stylus changing with the waveform slope. Only a zero radius stylus would perfectly follow the path cut by the cutting head. So of course records have a sound. You can read all about that at the https://pspatialaudio.com/index.htm website. It's just simple geometry that cause about 1% 2nd harmonic distortion for a 0.25 Mil stylus at 5 cm/s on a 1 kHz sine wave played on any turntable. Is that causing a grainy or veiled sound. Many folks swear that records are the opposite of grainy and veiled, yet the distortion is undeniably there due to the simple geometry.
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Oh, he does.
He is:
Bill Whitlock
President, Jensen Transformers, Inc.
Member, Audio Engineering Society
Senior Member, Institute of Electrical and Electronic Engineers
The slide deck of one of his talks was already posted by me, but of course it was ignored by people uninterested in the scientific facts.
The theory is in the next attached document.
EDIT: You might want to search for the words 'veiled' or 'grainy' in the first document.
Also please see the reference documents listed at the end of the 2nd document.
OK, so that is all standard electrical engineering. I would say 99% of that applies to concert or recording studio systems where equipment is spread around a large room or venue with equipment plugged into multiple power outlets creating obvious ground loops. So the professional equipment uses isolation transformers and differential outputs and inputs to reduce the susceptibility to common mode noise and ground loops. I've setup equipment for concerts and recording studios, so I'm familiar with all of that. None of that is magical "veiled or grainy" sound. It's just plain electrical susceptibility where the noise can be measured and is audible when the music isn't playing. In a home stereo you avoid all of that with short cables, quality shielding on single ended signals, a ground star, and plugging into a single outlet.
If your grainy sound is due to RF susceptibility, there is a strong RF source near by and you have a cable acting as a loop or straight wire antenna and that's easy to deal with. Twist the wire, reduce the loop area, use a ferrite bead to increase the common mode impedance or get well designed audio equipment that isn't converting the common mode RF signal into an audible signal. This is all easy to measure as the signal is there all the time, even when the audio input is not. You should be able to walk up to your speaker and hear it if it is there when the music is not playing. It doesn't magically appear only when the music is playing.
The last system I worked on that had this type of problem had a very famous and expensive tube amplifier from the 1960's. Most of the systems with these issues have a component that simply didn't follow good design practices leaving them open to receiving noise in various ways, often rectifying the RF and then adding the demodulated waveform to the audio.
If your grainy sound is due to RF susceptibility, there is a strong RF source near by and you have a cable acting as a loop or straight wire antenna and that's easy to deal with. Twist the wire, reduce the loop area, use a ferrite bead to increase the common mode impedance or get well designed audio equipment that isn't converting the common mode RF signal into an audible signal. This is all easy to measure as the signal is there all the time, even when the audio input is not. You should be able to walk up to your speaker and hear it if it is there when the music is not playing. It doesn't magically appear only when the music is playing.
The last system I worked on that had this type of problem had a very famous and expensive tube amplifier from the 1960's. Most of the systems with these issues have a component that simply didn't follow good design practices leaving them open to receiving noise in various ways, often rectifying the RF and then adding the demodulated waveform to the audio.
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Not really. You are wrong about multiple things, so your understanding may still be too superficial.
Regarding magical sound, be it grainy, veiled, or anything else. Its often not magical at all, even though some people may start calling it that. Like schoolyard name calling kids do.
That's because kids don't usually have a solid enough understanding of the physics and math. So they resort to what they do know, which is name calling and ganging up on people they choose to pick on.
Regarding magical sound, be it grainy, veiled, or anything else. Its often not magical at all, even though some people may start calling it that. Like schoolyard name calling kids do.
That's because kids don't usually have a solid enough understanding of the physics and math. So they resort to what they do know, which is name calling and ganging up on people they choose to pick on.
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Of course. That's why my systems have no audible noise. I basically spent most of my career producing solutions to noise issues in microvolt level heart monitoring systems and touch screens. So my understanding may be superficial, but I've designed lots of systems that rejected massive levels of noise. Here's the slide from you expert that clearly states that "grain and veil sound" is from poor RF immunity which is easy to quantify as it is captured in standards around the world. This is simple stuff that modern equipment handles through proper design and without any exotic boxes added on. Straight from your experts slide. Even I can read a short presentation in a few minutes. This is nothing new.
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If it's signal correlated you put a signal in, measure what comes out and subtract the input signal from the output signal. What's left after matching gain and phase of the device transfer function is the signal correlated noise. If you like you can graph it, perform some math on it, look at the peak to peak and RMS levels, frequencies, play it out a speaker. How do you do it? If it is at all relevant, it will be easy to detect.
Subtraction is a very useful thing. Here I measured the baseline noise, no signal from the left and right channels of my phono preamp, turntable, cartridge system and subtracted the left from the right channel. One channel had several dB more noise than the other. This pointed to a problem in the turntable internal wiring or the cartridge. It was ultimately tracked down to the cartridge itself.
It is useful to capture signals digitally and then view or process them with software like REW, Arta or GNU Octave.
Subtraction is a very useful thing. Here I measured the baseline noise, no signal from the left and right channels of my phono preamp, turntable, cartridge system and subtracted the left from the right channel. One channel had several dB more noise than the other. This pointed to a problem in the turntable internal wiring or the cartridge. It was ultimately tracked down to the cartridge itself.
It is useful to capture signals digitally and then view or process them with software like REW, Arta or GNU Octave.
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You can measure noise floor with and without signal. That's one valid test. (For SD dacs, a standard test to measure noise versus a digital input signal that produces a DC offset; the DC offset is stepped and a noise measurement is taken for each step. Of course the measured "noise" may not be noise at all, but it looks like it on an FFT)
You can measure changes in spectral line noise-skirt base-width. That's another valid test provided its done in a calibrated way.
A lot depends on where the noise is coming from and how its getting correlated with the audio.
You can measure changes in spectral line noise-skirt base-width. That's another valid test provided its done in a calibrated way.
A lot depends on where the noise is coming from and how its getting correlated with the audio.
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So long as we are on the subject of noise, hopefully we are all up to date on the nature of white noise, and its appearance on a typical audio FFT.
There is a graph of white noise types in this article, which may surprise some people:
https://www.edge.org/response-detail/11715
It turns out that noise can look white on an FFT, and even if at a very low level, it may or may not be audible. It all depends on the process producing the noise and its probability distribution (which is related to the phase distribution of the noise).
In the most extreme case white noise can be in the form of a Dirac Function (impulse).
There is a graph of white noise types in this article, which may surprise some people:
https://www.edge.org/response-detail/11715
It turns out that noise can look white on an FFT, and even if at a very low level, it may or may not be audible. It all depends on the process producing the noise and its probability distribution (which is related to the phase distribution of the noise).
In the most extreme case white noise can be in the form of a Dirac Function (impulse).
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Thank you for the articles/briefing. I’ve been a fan of isolation transformers for my electric guitar for quite some time now. They really do clean up the signal a lot! If you play at high gain with low distortion you probably need them. They are also great for using two amplifiers.
Back to the salt boxes, I don’t see how they apply to a proper grounding or shielding scheme. How do they work as a noise filter? What are the physics involved?
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