2. cables
  3. 195218-198226

How can different CAT5/6 cables affect sound.

While is is beyond doubt that analog cables affect sound quality and SPDIF, TOSlink and AES/EBU can effect SQ, depending on the buffering and clocking of the DAC, I am at a loss to find an explanation for how different CAT5 cables can affect the sound.

The signals over cat5 are transmitted using the TCP protocol.  This protocol is error correcting, each packet contains a header with a checksum.  If the receiver gets the same checksum then it acknowledges the packet.  If no acknowledgement is received in the timeout interval the sender resends the packet.  Packets may be received out of order and the receiver must correctly sequence the packets.

Thus, unless the cable is hopeless (in which case nothing works) the receiver has an exact copy of the data sent from the sender, AND there is NO timing information associated with TCP. The receiver must then be dependent on its internal clock for timing. 

That is different with SPDIF, clocking data is included in the stream, that is why sources (e.g. high end Aurenders) have very accurate and low jitter OCXO clocks and can sound better then USB connections into DACs with less precise clocks.

Am I missing something as many people hear differences with different patch cords?

retiredaudioguy

Showing 1 response by nubiann

nubiann
32 posts
 

I don’t speak from huge experience but you may know from my previous posts here, following much research many seemingly dumb questions asked, I have taken a deep dive into the world of Streaming, finally settling on the Lumin X1.

My direct experience since has been interesting, first I had to overcome the issue of connection my router is in a different part of the home from my Lumin so I had to use the TP Link powerline which to its credit worked first time and provided a stable Ethernet connection. I had a Cat cable not sure if it was a 5 or 6. I think Cat 6 but it was fine to get the Lumin streaming.

Whilst I didn't at first notice any significant noise, I changed after a while to a CAT 8 cable, not for speed or bandwidth, more for noise rejection. My own research had prompted me to try.

Cat6: Typically, unshielded or UTP (Unshielded Twisted Pair), though Cat6a may be shielded.

Cat8: Always fully shielded (usually S/FTP – Shielded Foiled Twisted Pair).

My intention was in one change to reduce or eliminate the possibility of crosstalk and EMI

The result was notable not in the way I had expected. It was more about the move more towards a blacker background that’s how I describe the reduction in noise. It made me speculate that its not about the bits it’s about the removing the interference and maybe crosstalk in non-shielded.

My thoughts moved to perhaps trying the Lumin’s Optical in Via SFP & Optical Fibre input. This intrigued me but I knew it could involve some difficult threading of 20 metres of Optical Fibre back to my router.

I tried short CAT8 cable into a Ethernet to Optical Converter then using a short a High quality/purity optical fiber cable to the Lumin. The logic being complete isolation from noise and the vagaries of ethernet cables.

I have listened to a good few hours using the optical solution and the gains are obvious and positive. I note how music just appears in the sound stage from total quiet, its eerie sometimes but never anything but impressive.

I cannot comment as to the Ethernet vs Optical sound differences except to say noise rejection/isolation definitely gave the optical connection a clear edge.

As to the sound vs analogue. The only comparison I have made recently is the best Royal Scam stream I could find vs the Acoustic Sound UHQR 45rpm Vinyl played via a much-modified Linn LP12 Sondek. I can confirm that it wasn’t really close. The vinyl completely destroyed the streamed version.

So, I am not naive to think that is it Vinyl beats Streaming, I know from other streams that it depends on the quality of the stream vs the quality of the analogue media and the capability of both sets of reproduction hardware but the limited experience has taught me that in this the age of digital that my record player can and does still utterly engage me.

That said the Lumin X1 has opened up a whole new world and way of listening. It can sound astonishingly great and often does.

I now know I have different ways to listen to an appreciate music and that’s the big win here for me.

So the ethernet cable discussion doesn’t really come down to bits, for me it’s more about noise specifically crosstalk and EMI.

I hope sharing my experience so far helps.

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