network cable sounds different(ABX TEST)

[uusuke]

https://www.mobile01.com/topicdetail.php?f=348&t=6953606
Some people claim to be able to tell the difference between Ethernet cable
And passed ABXTEST
The reason may be due to the 60HZ hum(Data comes from smartphone recordings)

Is this a common situation or an extreme situation?

Try my best to write a simple summary​

​

goldbingo(author) use Lumin T1 + Heidelberg 120 Gold , ATC SCM11 V
and Recording using smartphone
network cable use "AIM NA7"&"ordinary cable"
Then listen to the recorded file(abxtest)
can distinguish

AIM NA7 Website link

Then another one (Volf) use"LINKOMM Cat8" & "ordinary cat5"
Bluesound PowerNode + Focal Aria K2 906+ iphone15(for recording)

"LINKOMM Cat8" & "ordinary cat5"
Record 5 times each
get

A2 A3 A4 A5 has 60HZ HUM
B1 B2 B3 B4 B5 does not have 60HZ HUM
There is something abnormal about A1

 

[SIY]

Or a badly set up test. The translation is a bit tough to follow but it looks like they used iPhone recordings?

 

[Berwhale]

There are many threads on ASR discussing network technologies and why they don't have any impact on sound (unless something is seriously broken).

e.g. https://www.audiosciencereview.com/...ble-does-it-help-with-network-streamer.48659/

 

[audio_tony]

Any test (apart from tests of speakers / headphones of course) made by recording the output from a speaker simply cannot be valid.

There are just too many variables, e.g. did the occupants of the room stand / sit in the same place for each recording?

Was the ambient noise the same for each recording (almost certainly wasn't).

Tests like this are just a pointless waste of time.

 

[MaxwellsEq]

The test is hard to follow in translation, but it looks like a CAT8 cable was used. In which case they probably created a ground loop with the screen, which will degrade the signal to noise ratio and may be audible. The charts seem to suggest this. CAT5 is usually unscreened, can't create ground loops and is more than good enough for domestic audio

 

[uusuke]

Any test (apart from tests of speakers / headphones of course) made by recording the output from a speaker simply cannot be valid.

There are just too many variables, e.g. did the occupants of the room stand / sit in the same place for each recording?

Was the ambient noise the same for each recording (almost certainly wasn't).

Tests like this are just a pointless waste of time.

I agree with you,BUT I noticed 60HZ hum

The test is hard to follow in translation, but it looks like a CAT8 cable was used. In which case they probably created a ground loop with the screen, which will degrade the signal to noise ratio and may be audible. The charts seem to suggest this. CAT5 is usually unscreened, can't create ground loops and is more than good enough for domestic audio

Cat8 has metal connectors
It may be the problem

 

[DVDdoug]

60Hz hum shouldn't come form the cable because hum is "analog" and the data is digital. And Ethernet connections are transformer isolated at both ends (so you shouldn't get ground loops).

 

[Berwhale]

I agree with you,BUT I noticed 60HZ hum


Cat8 has metal connectors
It may be the problem

There is quite a bit of information about galvanic isolation of Ethernet in this thread: https://www.audiosciencereview.com/...ic-isolation-of-utp-cable.38310/#post-1350034

 

[kemmler3D]

It sure looks like one of the cables caused a ground loop. I understand this is not supposed to happen, but it's not exactly rare to get a defective cable, either.

 

[Barrelhouse Solly]

In general, assuming the cable and associated hardware are working properly, I think it's impossible. Network cables transport binary code. As long as the high and low pulses are identifiable to whatever is receiving them there should be no effect on how they're translated into sound.

 

[Blumlein 88]

Tons of issues. The main thing though is the title should be, 60 hz hum detected in ABX test. Not exactly an earth shattering result.

 

[radix]

One cannot willy-nilly use shielded cables. You need a proper grounding infrastructure that prevents ground loops. Unless they floated the ground on one end, they likely introduced a ground loop.

Apart from data centers or very noisy manufacturing environments, there's little need for shielded cables in a home or even office environment.

 

[antcollinet]

One cannot willy-nilly use shielded cables. You need a proper grounding infrastructure that prevents ground loops. Unless they floated the ground on one end, they likely introduced a ground loop.

Apart from data centers or very noisy manufacturing environments, there's little need for shielded cables in a home or even office environment.

I don't think I've ever seen stp cables used outside of a heavy industrial application. I agree - simply not needed... and for audio, counter productive.

It is typical audiophilia ignorance...... Ah, shielded must be better, and lets spend at least $500 on a patch cable.

For audio networking the cheapest nastiest unshielded patch cable will work better than any shielded one due to the non proliferation of ground loops.

 

[MaxwellsEq]

60Hz hum shouldn't come form the cable because hum is "analog" and the data is digital. And Ethernet connections are transformer isolated at both ends (so you shouldn't get ground loops).

They mention CAT8 which is screened and can cause ground loops.

 

[MaxwellsEq]

There is quite a bit of information about galvanic isolation of Ethernet in this thread: https://www.audiosciencereview.com/...ic-isolation-of-utp-cable.38310/#post-1350034

They mention CAT8 which is screened and can cause ground loops.

 

[MaxwellsEq]

In general, assuming the cable and associated hardware are working properly, I think it's impossible. Network cables transport binary code. As long as the high and low pulses are identifiable to whatever is receiving them there should be no effect on how they're translated into sound.

They mention CAT8 which is screened and can cause ground loops

 

[Berwhale]

They mention CAT8 which is screened and can cause ground loops.

Yes, I know. But rather than state the obvious 'it's your cables mate', I prefer to provide an educational reference.

In order to understand why Shielded Twisted Pair (STP) cables may be worse than Unshielded Twisted Pair (UTP) cables for audio applications, one needs to understand how galvanic isolation works for the signal wires and how this is separate from the shield which can link two devices electrically and provide a path to ground.

There seems to be a widespread belief (stoked by marketing) that CAT8 is 'better' than CAT7 which is 'better' CAT6, etc. and that STP is 'better' than UTP, when the reality is that CAT5e UTP is all most people require. I recently upgraded my home network to 2.5GbE and it's working perfectly well over the CAT5e I installed 15 years ago.

 

[somebodyelse]

60Hz hum shouldn't come form the cable because hum is "analog" and the data is digital. And Ethernet connections are transformer isolated at both ends (so you shouldn't get ground loops).

Only the signal pairs have transformer isolation. If there is a shield present it is usually connected to ground at both ends, which is why it may form a ground loop.

 

[Verig]

This is one very clear case where "being better" really does not translate well to home (hifi) application.