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Iceman 16

Does rfi makes a system sound brighter?

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Before I start please I don’t really want this thread to become never ending cable debate. I’ve asked this question cause I’ve done some power cable mods. I’m using Viablue X40 bought from Germany and diy Furutech and IEgo plugs on each ends. Now I’ve search and read some reviews about “screened” or shielded mains cable in which the shield is connected to the ground (mains plug only). The difference I’ve noticed was that the sound became less bright or lively

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Just now, CnoEvil said:

At a "guess", I would say that RFI would make the sound slightly harsher (which is different to brighter).

What would the the logic there?

I don't know enough to comment but the discussion needs to be about mechanisms for the much higher RFI frequencies to have an impact at audio frequencies.

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Super Wammer

Mains cables are not a particular interest of @Fourlegs but he knows a thing or two about RFI.

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Posted (edited)
1 hour ago, MartinC said:

What would the the logic there?

I don't know enough to comment but the discussion needs to be about mechanisms for the much higher RFI frequencies to have an impact at audio frequencies.

I'll leave that one to Fourlegs.

Ps. I found this explanation on the Atlas Website: https://www.atlascables.com/assets/files/pdfs-technical/DNA_of_Atlas_Power_Products-Apr13.pdf

Edited by CnoEvil

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Posted (edited)
13 hours ago, Iceman 16 said:

Before I start please I don’t really want this thread to become never ending cable debate.

Triumph of hope over experience?

But, yes, I'd tend to agree removal of 'noise' often results in a 'calmer' presentation which may be perceived as superficially duller or even less 'impressive.' FWIW, I think it's quite well expressed here:

https://darko.audio/2019/04/a-short-film-about-cd-playback-w-hegel-ps-audio-pro-ject/

Edited by notevenclose

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Hi,

I think it is entertaining that the discussion of RFI present on cables (power and speaker cables) causes the system to sound bright, or harsh, whatever the adjective.

Yet, when it comes to class D which outputs significantly more higher frequencies from 20kHz+ into the speaker than class A/B, and usually uses a switch mode power supply, that class D is seen as neutral, or transparent, or clinical - all adjectives i have seen to describe class D.

The manufacturers of class D even restrict the measurement bandwidth of class D amplifiers to ensure that their figures look good, saying that no one can hear above 20kHz, so this approach is ok. No one bats an eyelid at this. Not even the so called golden eared reviewers.

The energy in RFI is 1,000 to 1,000,000 times less than the crap put out 20kHz+ from a class D amplifier.

I suppose we should not let facts get in the way of peoples perception. :D

Regards,

Shadders.

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13 minutes ago, Shadders said:

Hi,

I think it is entertaining that the discussion of RFI present on cables (power and speaker cables) causes the system to sound bright, or harsh, whatever the adjective.

Yet, when it comes to class D which outputs significantly more higher frequencies from 20kHz+ into the speaker than class A/B, and usually uses a switch mode power supply, that class D is seen as neutral, or transparent, or clinical - all adjectives i have seen to describe class D.

The manufacturers of class D even restrict the measurement bandwidth of class D amplifiers to ensure that their figures look good, saying that no one can hear above 20kHz, so this approach is ok. No one bats an eyelid at this. Not even the so called golden eared reviewers.

The energy in RFI is 1,000 to 1,000,000 times less than the crap put out 20kHz+ from a class D amplifier.

I suppose we should not let facts get in the way of peoples perception. :D

Regards,

Shadders.

Assuming that's as universally true as you're suggesting, it's only really relevant to anyone who actually owns a Class D amp. Whereas I imagine pretty much everyone will need mains cables.

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Dealer

RF noise does cause brightness, harshness, loss of bass definition, muddied mid range etc etc but it had to get to somewhere that it can do damage by causing intermodulation distortion in sensitive analogue stages.

If it is environmental RF noise then appropriate screening can help to keep it out (but not all screening works with RF frequencies). Screening will do no good if the noise has already got into a conductor or into the ground plane.

One does not actually hear the RF noise itself as it is way above audible frequencies and that is why it is the intermodulation distortion effects which are heard. (Think also of how radio waves carry signals by FM (frequency modulation) to partly explain this process of the RF noise being audible.

Many say that modern kit has sufficient isolation or filtering to mean that RF in mains or inputs is not an issue but this is rarely enough. Speaker wires can act as RF aerials and then feed the RF noise back into the amplifier where it can cause intermodulation distortion.

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Dealer
22 minutes ago, Shadders said:

I suppose we should not let facts get in the way of peoples perception. :D

Regards,

Shadders.

Well you certainly don't. Entertaining as ever but a very loose understanding of the issues unfortunately.

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1 minute ago, notevenclose said:

Assuming that's as universally true as you're suggesting, it's only really relevant to anyone who actually owns a Class D amp. Whereas I imagine pretty much everyone will need mains cables.

Hi,

The point is, even with the class D noise on its output etc., that no one makes any comment on this, and praises the class D clinical/transparent/neutral sound.

For RFI which is 1,000 to 1,000,000 times less noise, it is a discussion point, where some people may believe RFI is an issue.

So, if you cannot hear the class D amplifier noise issues, then how on earth can you hear RFI which is 1,000 to 1,000,000 lower in power, and is by its definition, outside the human hearing range (RFI is 30MHz to 10GHz - https://www.jmkfilters.com/faq.htm)

Regards,

Shadders.

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Dealer
6 minutes ago, Shadders said:

Hi,

The point is, even with the class D noise on its output etc., that no one makes any comment on this, and praises the class D clinical/transparent/neutral sound.

For RFI which is 1,000 to 1,000,000 times less noise, it is a discussion point, where some people may believe RFI is an issue.

So, if you cannot hear the class D amplifier noise issues, then how on earth can you hear RFI which is 1,000 to 1,000,000 lower in power, and is by its definition, outside the human hearing range (RFI is 30MHz to 10GHz - https://www.jmkfilters.com/faq.htm)

Regards,

Shadders.

The effect of RF noise is made audible by it causing intermodulation distortion on the audible range. No one is suggesting that one hears RF direct and to suggest that it is not an issue because the frequency of RF is outside the frequency of human hearing is to completely misunderstand the physics of what is happening.

It is not a matter of BELIEVING that RF noise is an issue. It is a fact which is well understood.

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7 minutes ago, Fourlegs said:

Well you certainly don't. Entertaining as ever but a very loose understanding of the issues unfortunately.

9 minutes ago, Fourlegs said:

Many say that modern kit has sufficient isolation or filtering to mean that RF in mains or inputs is not an issue but this is rarely enough. Speaker wires can act as RF aerials and then feed the RF noise back into the amplifier where it can cause intermodulation distortion.

Hi,

Unless you live under or within 1 mile of a radio transmitter (not a mobile base station), then the noise introduced into a speaker cable is of such low power density, that the thermal noise density of the feedback resistors etc., exceeds the power density of the induced signal within the speaker wires.

Any intermodulation that may possibly occur, is therefore non-existent.

As long as the casework of the equipment is metal, and the lower voltage connections (RCA/Phono) still have the screen connection, then there will be no induced noise. The thickness of the screen or metal casework is sufficient to ensure that the at the relevant power and frequency, the skin depth is significantly lower than the cable screen or metalwork thickness.

Regards,

Shadders.

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Super Dealer

RF could be a factor if your equipment is extremely poorly designed .

Keith

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I’ve just watched this video from Paul of PS Audio.

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