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Extreme Snake Oil

Geert

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What should be the power than?
A 0,5dB rise in voltage corresponds to a ratio of 1,059254. Translated to power (quadratic relationship) it's a factor 1,122, not even close to double (factor 2). And you measure an even bigger difference.
 
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kongwee

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A 0,5dB rise in voltage corresponds to a ratio of 1,059254. Translated to power (quadratic relationship) it's a factor 1,122, not even close to double. And you measure an even bigger difference.
70dB SPL on my phone, it drop to 65dB SPL with just -0.5dB on tone generator. Forget to mention dB SPL.
 

antcollinet

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70dB SPL on my phone, it drop to 65dB SPL with just -0.5dB on tone generator. Forget to mention dB SPL.
The whole point of dB is they are equivalent. If the system is reasonably linear, and you are measuring anechoically, then 0.5dB input voltage change should result in 0.5dB of SPL change.

If you are in a room with reflections, and the phone (or just you, or anything else) are moving, then all bets are off. Even so, if you are seeing 5dB SPL change for 0.5dB tone change - then there is something wrong with your system, or with your SPL meter.
 

Geert

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if you are seeing 5dB SPL change for 0.5dB tone change - then there is something wrong with your system, or with your SPL meter.

Just moving the phone half a foot might throw of the measurement.
 

kongwee

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The whole point of dB is they are equivalent. If the system is reasonably linear, and you are measuring anechoically, then 0.5dB input voltage change should result in 0.5dB of SPL change.

If you are in a room with reflections, and the phone (or just you, or anything else) are moving, then all bets are off. Even so, if you are seeing 5dB SPL change for 0.5dB tone change - then there is something wrong with your system, or with your SPL meter.
So if I move my phone away double from my iMac, you still can keep 1:1 of dBu to SPL?

Also in word because of reflection, from -0.5 dBu and add 0.5dBu, will be boost hell over 5 dB SPL. What seem tiny on graph will be sufficient on ears.
 
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antcollinet

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So if I move my phone away double from my iMac, you still can keep 1:1 of dBu to SPL?

Also in word because of reflection, from -0.5 dBu and add 0.5dBu, will be boost hell over 5 dB SPL. What seem tiny on graph will be sufficient on ears.
In a room - if anything is moving - your measurements are meaningless.
 

Geert

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Also in word because of reflection, from -0.5 dBu and add 0.5dBu, will be boost hell over 5 dB SPL. What seem tiny on graph will be sufficient on ears.

No it won't. A cable boosting a frequency range by 0,5dBu will also boost SPL in that range with 0,5dB, room reflections don't change that.
 

Galliardist

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Everybody recommends better specs, whether they can hear the difference (almost never) or not (almost always).
@amirm doesn’t necessarily. If you look at the recommendations list you will find the Wilson Audio TuneTot is recommended over other “better measuring" speakers. The sample measured with quirks but passed a controlled listening test.
You'll also find recommended electronics with a range of measured responses in the index.

And if you poke around the site, you'll find recommendations for different devices for different needs. I don't think your stereotyping applies here.
 
OP
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Spkrdctr

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A 0,5dB rise in voltage corresponds to a ratio of 1,059254. Translated to power (quadratic relationship) it's a factor 1,122, not even close to double (factor 2). And you measure an even bigger difference.
Geert, you went all sciency on us. Good thing I had my morning coffee to read this otherwise I could have fallen out of my chair! :)
 

Adi777

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"The audibility of the influence of cables is due to backward intermodulation. For example, if we mix two over-acoustic frequencies f1 - 1001000 Hz and f2 - 1000000Hz, we get the sum of these two frequencies f1+f2=2001000 and we get the difference f2-f1=1000Hz (1khz) and this signal is heard as the influence of the cable by mixing the signals."


Could any of you relate to this? I'm guessing it's BS, but I'd like to respond to the author of this text. I'm curious what he'll reply to me.
 

symphara

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"The audibility of the influence of cables is due to backward intermodulation. For example, if we mix two over-acoustic frequencies f1 - 1001000 Hz and f2 - 1000000Hz, we get the sum of these two frequencies f1+f2=2001000 and we get the difference f2-f1=1000Hz (1khz) and this signal is heard as the influence of the cable by mixing the signals."


Could any of you relate to this? I'm guessing it's BS, but I'd like to respond to the author of this text. I'm curious what he'll reply to me.
Sinusoids don’t sum like that. There are plenty of lectures online.
 

egellings

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"The audibility of the influence of cables is due to backward intermodulation. For example, if we mix two over-acoustic frequencies f1 - 1001000 Hz and f2 - 1000000Hz, we get the sum of these two frequencies f1+f2=2001000 and we get the difference f2-f1=1000Hz (1khz) and this signal is heard as the influence of the cable by mixing the signals."


Could any of you relate to this? I'm guessing it's BS, but I'd like to respond to the author of this text. I'm curious what he'll reply to me.
It looks implausible to me. An effect, if any, would be too microscopic to notice.
 

Adi777

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@symphara Hi, he answered me:

"I did a quick skim without getting into the math. Well, interesting. But this only proves that a large amount of superimposed interference produces harmonics. Well, if the signals are summed up, the signal becomes more rectangular. And the rectangle is 100% THD."
 
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