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Noise reduction -why the rage now ?

Is it better science ? Or more needed today with the ’surge’ of switching power supplies, smart phones and Wi-Fi routers ? Then, higher-frequencies in digital interfaces -now megahertz and gigahertz.

The problem with the "needed more today" theory is that one, listeners are hearing things they never heard before. One report is from Paul of PS Audio (on his blog) stating that a 4K power cord transformed his system. Yet he sells a Power Plant.

Two, many reports of lower noise (in the last 10 years) were in systems with linear power supplies, not switch-mode.

Three, for digital, many people were using AES/EBU or i-squared interfaces. These don’t have the noise concerns of USB.

Fourth, many people listen at night. They know better, due to the problems of a noisy day-grid.

Yet, there it is -large gains from the latest power conditioners, ground blocks and after-market power cords. To me, today’s science is much better at doing this. Along with the "need today".
jonnie22

Showing 12 responses by geoffkait

geoffkait's avatar
geoffkait
23,365 posts
 
Gee whiz, isn’t it obvious I’m disputing this? This conversation can serve no purpose any more.
geoffkait's avatar
geoffkait
23,365 posts
 
The digital signal is not the waveform either. Good try, though. Better luck next time.
geoffkait's avatar
geoffkait
23,365 posts
 
The “signal” is alternating current and voltage virtually all the way from the wall outlet and power cord to the speaker terminals. The “audio waveform” per se doesn’t make its appearance until the speakers produce it. Prior to the speaker the signal is voltage and current. It’s not music until the speakers produce it.

I have not seen any studies regarding your question how RF or vibration affect the signal in wires.
geoffkait's avatar
geoffkait
23,365 posts
 
As I said, the signal in electronics and wire is not the audio waveform, it’s an electromagnetic wave. Let’s call it theoretically a PURE electromagnetic wave. Unfortunately that PURE EM wave is subject to INTERNAL and EXTERNAL interference from RF and vibration, which produce NOISE or DISTORTION in the audio signal. This is why it’s necessary to reduce as much as possible ALL SOURCES of RFI and vibration. There is no substitute for Signal to Noise + Distortion Ratio. 🤗
geoffkait's avatar
geoffkait
23,365 posts
 
I went to a Jimi Hendrix concert in MD outdoors in a thunderstorm once. He was picking up a local radio station playing a guess what? Jimi Hendrix song, was it Foxy Lady?, on his electric guitar. Hendrix held his guitar up to the microphone so everyone could hear Foxy Lady, “Thank you, thank you.”
geoffkait's avatar
geoffkait
23,365 posts
 
I suspect you missed my points. My point is that RF is not in the audio bandwidth. And the audio signal is not the audio waveform.
geoffkait's avatar
geoffkait
23,365 posts
 
williewonka
One might argue that the EMI/RFI generated by digital gear like phones is way above the human audible spectrum and some will debate their impact on sound quality - but I hear no evidence of sound quality degradation if I place digital devices close to components OR cables.

>>>>>This brings us back to the question: What is the signal? And why is it subject to RFI/EMI, which is not only above 🔝 the human audio spectrum, it’s not even in the same spectrum? 😀 (One is the acoustic spectrum, the other is the electromagnetic spectrum.)

One might also ask why seismic vibration interferes with the signal, too, even though it’s below ⬇️ the human audio spectrum; at least it’s in the same spectrum. 🤗 By inspection the signal in all the electronics and wire is not the audio waveform. ♒️ Hope this helps.
geoffkait's avatar
geoffkait
23,365 posts
 
You say no, I say yes, you say hello, I say goodbye. 
geoffkait's avatar
geoffkait
23,365 posts
 
The number of cellphones, tablets, TVs and wireless networks has dramatically increased in the last 40 years. Plus the number of RF producing microchips in audio components have increased dramatically. You don’t have to be a rocket scientist to figure it out. RF is by definition high frequency. Hel-loo!
geoffkait's avatar
geoffkait
23,365 posts
 

Huh? The article you linked actually states the RF problem is getting worse. To whit,

“Nevertheless, the RF noise problem is increasing. Although most devices pollute less than their predecessors, we have far more of those devices. Other sources, such as the power grid, are expanding as wind farms and solar households connect to it. Such devices need to switch large amounts of DC power at a 60-hertz or an even faster rate whenever they feed excess generated power back into the grid. If not done properly, this could also feed large amounts of noise into the power grid. This risk is magnified when the solar and wind systems operate without expert maintenance inside millions of ordinary homes.”


geoffkait's avatar
geoffkait
23,365 posts
 
millercarbon
When in fact the worst kind of noise is the sort that gets interwoven right into the signal.

>>>>>Gee, you don’t say? Why, it almost sounds like you think the signal is the audio waveform. What is this signal you speak of? 
geoffkait's avatar
geoffkait
23,365 posts
 
As long as your cell phone is still working you’ve got an RFI problem. If you could see RF your whole room would be lit up like a Christmas tree. 
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