Interesting thread…no science here but my experience is Ethernet cables can both make or not make an audible difference. I feel it depends on many different variables. Modem/router and their quality and power supplies, switch, optical isolation, Lan filters, power quality/conditioning, streamer quality and more. It seems to me it’s all about removing line pollution/noise. If you have a revealing system and have done an excellent job cleaning up these variables the cable may not make a noticeable difference. If not, then the cable quality and it’s shielding should make a notable SQ difference. I have a pretty revealing system and have cleaned up the above variables. I have tried several different low/mid level ethernet cables and have never heard a SQ difference. Now for those with super high revealing expensive systems with very high end cables improvement may be gained.… I don’t have experience at that level. I have made a few changes and ordered 2 different pairs of higher end cables to try one more time to see if improvement can be heard. Note: I have heard very noticeable differences in improved SQ with all other cable types especially upgrades to USB and IC’s.
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?