Well, so far we have people who think 5e is better than CAT7 and the other way around. But, the data supports that SHIELDS are NOT going to IMPROVE the signal quality, but the very opposite in a noiseless world. The math and calculations show exactly that. SHIELDS are a benefit ONLY if you have noise sever enough to drop the Ethernet error correction to below the requirements, which is exceedingly rare.
CAT 7 uses the fact that removing internal pair-to-pair NEXT allows an improvement in S/N that exceeds the DAMAGE the shields do to impedance uniformity and return loss performance. RL (lost by reflected energy) gets worse, but the S/N gets better so there is an overall improvement. For FTP, or overall shielded cable the shield hurts internal NEXT by up to 6 dB on average. That fact means you have 6 dB MORE noise to be shielding to break even in performance. The advantage has to be from high terrestrial interference. The internal design of the FTP cable pairs and shield is super critical to work well as the NEXT is not going to be as ultimately good as UTP. But, it is still well above what Ethernet requires to meet BER standards. Generally, if you start with CAT 6 UTP and apply a shield, it is 5e internal Shannonâs law BW cable, But, it wonât change with higher external noise so thatâs the reason to use it.
The basic tenant is simply how far above the noise is the signal? The signal DOES NOT KNOW how it got to the level it is any more than the noise does. Shannonâs law (the cableâs theoretical BW) is based off of where the signal and noise are.
A shields geometric variation from the core components negatively impacts the cable impedance, and signal transfer and eventual BER erosion, far more than the pairs C-C does (see the graphs). But, if we DO NOT have a shield, the C-C is more important and the influences on RL for the same error in geometry and are less severe (graph). How much does the impedance CHANGE with each mil of dimensional variation? External shields are far worse than C-C.
The closer the ground plane (shield) to the core components, the more severe the variation impacting the cables stability. But, this RL signal and attenuation loss (shields INCREASE attenuation!) has to be measured AGAINST the internal NEXT and external noise. So does all the bad stuff still represent more good stuff with the bad? If you have NOISE than yes, it can. No noise obviously means no. All Ethernet cables have some internal NEXT ânoiseâ so even with no external noise we have some inductive signal ânoiseâ.
CAT7 was popular in Europe for several good reasons. They canât throw miles of cable away. Cableâs were made as good as possible so they stay in service longer. This means 22 AWG to offset shielding effects on attenuation was used, and both INTERNAL / EGRESS and EXTERNAL / INGRESS shields were designed in from the start.
Once the NIC card sees the data relative to the noise it has no clue if it was CAT5e to CAT7 that got it there. None. It sees the Shannonâs law BW levels and the BER that follows that value.
I use Ethernet power-line adapters, W10 PC to a Bridge II with 26 AWG UTP stranded patch in my DS DAC. This is worst caseâŚon purpose. It sounds wonderful. Yep, the changes are SOURCE derived, not the bit stream. Audio does not come remotely close to exceeding 10baseT Ethernet BER requirements for bit perfect error free streaming.
A cableâs ultimate performance is simply the Shannonâs law BW
Belden series 1200 = 1.2 gb/s
2400 = 2.4 gb/s
3600 = 3.6 gb/s
4800 = 4.8 gb/s
It does not matter HOW you get there, the S/N determine how the bits and BER will end up. Since Digital is really analog superposition to create our square waves, Ethernet cable is measured in the ANALOG domain, too. Every test is analog. And yes, this can be directly mapped to digital eye pattern tests to show the signal to noise performance.
I hate to bring data to the table of beliefs, but thatâs what I do. ICONOCLAST does that. Rs indeed shows the impact of the BW linearity over lesser designs. It is MEASURED. So getting that right, and keeping R, L and C low requires unique designs. And, digital cables are like that, too. There are unique designs to increase the Shannonâs law BW and they are indeed measurable. Cableâs are not like us, they donât whine, cry, laugh or smile. They are a product of their design, period. We can measure that. Even attributes we canât yet measure are STATIC and will be consistent from location to location once proper inspections are defined.
Even with those âundefinedâ attributes the remaining ones have to be better to remotely work better. Iâve never seen this to be the case. I no magic variable that means we can toss one we currently know to impact transmission of analog or digital. None. Better is better.
Digital cables are hardly ignored. Ethernet has some of the best cable in the industry mass produced to keep costs down. This is a good thing, too. We all benefit from the high barrier of entry. Belden uses unique designs as physicals is indeed electrical. No way around that. This is NOT an opinion. It is physics.
I would use DT600e or 4800. 600e uses superior internal NEXT and 4800 uses superior attenuation with big copper to arrive at the same Shannonâs law bandwidth. They will work IDENTICAL delivering digital data! Where 4800 is useful is if you use POE and need low DCR for power over Ethernet. So again, differences can be MEASURED.
Hope this helps you all understand all this, it isnât easy and no one really wants to make it so in Audio. I will never have a $3,000.00 digital cable, or even more dollars, as the Shannonâs law BW driven BER says we donât need one. When we do, the VOLUME will drive the price. True, we can make placebo cables in small QTY that will indeed be $$$ but why? It isnât better just more costly. which is true, but I want cable that WORKS better not just to be expensive. ICONOCLAST does cost more, but it is MEASURABLY better, too. I would love for it to be common enough to drop in price.
The digital stream is defined at the AD. It can not CHANGE the âsoundâ or something really creepy is going on. It streams 0 and 1âŚperfectly. The DA can indeed alter the sound as firmware changes the filters responses. This is NOT the cable in any way. The DS DAC has had several firmware changesâŚand the cables remained the same yet the sound changed. It is the FILTERS alterations, not the cable or Bridge II.
Analog cables have been ignored, so I took the time to re visit them and improve ONLY measured performance. That remains in the design, hear it or notâŚthey are better. Digital has already been under intense pressure to improve and measurements show exactly that. So called audio digital baffles me as there are no repeatable improvement so whoâs to say it improved anything? Oh, trust your ears. I do. I hear nothing using 5e and up digital cables.
Best,
Galen Gareis
I hoped final streaming sound is easierâŚand Ethernet cabling is just one aspect.