Everything matter in the audio chain. Tests prove it!

Yawn. 🙄 News, no. Perhaps in the 70's...

See ieLogical CableSnakeOil for some of the reasons why.

Duh. My ears have proven "Everything matter in the audio chain" since I started stereo.  Including power and environment.

All those charts and graphs and my ears still has the last Hear Say,

The room and listening environment have more influence in the sound than cables ever will. You can't fix poor acoustics and/or poor speaker placement with band aids.

Their measurements seem to be done at 11,0dBu level, which corresponds to 989mW on a 8-ohm speaker. Although the graphs are very dynamic-looking, they will fit into a leeway of 0.2dBu, which corresponds to about 40mW on the 8-ohm speaker.

Will that be audible? The author claims it will.

As Albert Einstein said , not everything that counts can be counted.

Technics showed a graph over 30 years ago on one of their integrated amps 

and a pretty clean sign wave, vs a Airtight. Vacuum tube model . And stated Vacuum tube  is now obsolete , sonicly SS equipment at the time under even a bit of distortion was gritty and bright ,where the vacuum tube rolled off with even harmonics and smoother , SS amplification has come along way in 30 years and sounds very musical  , graphs  are good but don’t tell the whole story ,

also your Room can play a huge part of the equation  damping the room of 1st reflections ,bounce reflections ,Bass nulls  treating your room  should be on your short list.