Nearly all manufacturers do not advertise/exhibit their product measurements? Why?

The review of the Belden (Blue Jeans) Iconoclast XLR cable measurements appeared about the same to me as the Canare, the difference was the extreme price difference. The Iconoclast designer indicates that it should sound different due to construction matters affecting other electrical properties (such as timing). I cannot say that it is or isn’t inferior but it is noteworthy that it electrically measured in specific tests similar. If I were given it to test, I would also listen to it and to the Canare in a high quality audio system. If there is no difference, then I would choose the Canare for that system. if there is a difference, a significant one, then the tests were incomplete/inadequate. The Belden could sound worse though. Different results in other systems are also possible. If this listening comparison occurs in many systems with similar resuls, then the testing was probably adequate. My problem is that manufacturers of most cables do not provide tested measurements.

I have not heard Belden Iconoclast cables in any system. I didn’t know that they made a high end cable. When I went to their site, the cable components do not appear to vary much from more common, less expensive cables, including those made in China by Audioquest and others. Not even close to the high end cables I’ve heard. Harmonic Technology and XLO also made cables of similar complexity. The speaker cable components were even simpler. After viewing the Cardas video on cable assembly (and lack of testing), I have great reservations concerning expensive cables as well. Maybe it’s luck for the audiophile who finds a cable manufacturer who designs and assembles higher end or more costly cables that transmit sound better than inexpensive plain jane well measured cables. I’m just glad that I found a cable manufacturer whose cables do make a positive difference for nearly every system they are placed in.

As to tweaks, I say try it and if you like the sound results, keep it. Otherwise, return it. I tried many footers when a dealer continued to send them to me to evaluate. One was terrible under all equipment and about 8 others were more similar than different in effect.  None were inexpensive, ranging from $49 to $500 per footer, a broad range but cost more than most footers were in the 1980s (cones, silicone rings, springs, etc).  I think roller balls in captive devices were the next step, vibraplanes and then multi-density/elastomer type devices, almost all more expensive. 

It wasn't until I purchased the Townshend Seismic Sink that I decided to keep my VPI TNT VI in 2006.  It has terrible vibration isolation, much worse than the rubber block and spring footers of my VPI 19-4.  That Townshend is fantastic for turntable isolation (my equipment rack was not the problem, made of welded steel tubing filled with 50/50 shot and sand/dead sounding when struck).  
 

"The industry is transforming though because if they don’t measure, then I might. :)"

What unbelievable arrogance. No wonder people in the industry regard your site as a joke. You still have not answered if you actually ever check whether Yang sends you off the shelf products or cherry picked ones. This is now the fourth time I have put this to you. Scared? If you do check, show us scientific evidence that you do, else it is just your statement. Perhaps make a video showing an independent person check as you open an off the shelf product and one sent to you.
 

Yes, go ahead and measure my Synergistic Research Atmosphere X Euphoria SPDIF digital cable.  I would pay $25 to find out how it measures.  But I'm not sending it to you, you'll have to acquire one on loan from a retailer, SR or someone else using it and I will pay for the results. 

@holmz You are correct. He could have needed better fuses or IC cables or something else.

The question was:

1. how did you know it needed the power cord?
2. What is happening with the power cord that makes it better?
3. Is there a way to measure it?
4. or does it not manifest itself in a measurement?

However, several other friends tried the Pangea power cable. No go. They disliked it compared to whatever they had been using. I know how great my power cables sound on several systems and the lack of returns on 1000s sold privately. So, I lent him the less expensive, earlier model, just one and he was dumbfounded. He replaced all the power cables. He was ecstatically happy. I’m happy for him and after he also changed his pre-amp input tubes, I am happy to listen to his audio system.

Good for him.

Yes, I’m only telling fables in your opinion. Not! You can believe it’s just another story and the sound could be the same. Not!

Let me rePhrase it.

“How can I tell the difference between your story and a fable?”
How would I know whether it is true and a real thing or a psychological thing, or even just a story.

I’ve related how poorly his system reproduced low frequencies with very jagged sound and now a smooth sound up and down the scale.

OK- Is there a plot like @kota1 showed where the frequency response went from jagged to smooth?

Voices are full and forward (instead of floating in the rear and thin sounding). I was using my CDs which I am very familiar with. If that earlier system from 2019 were mine after spending nearly $1/2 million, I also would have been very disappointed. It may not be perfect but after a few changes (10X more expensive power cables, 5X less expensive input tubes) his now high end sounding system is one I would be proud to own (except it is only CD based, uploaded to a computer and thumbdrives, going through a computer directory, through a Berkeley USB something or other to the DAC, then pre-amp then tri-amped multi-box speaker system). Too much work for me, I just plop the CD into the transport (or work a little more with LPs, 78s and R2R).