because those components have that signature compared to straight wire. And this signature cannot be measured. Same with all audio wires. Some sound dull, some sound neutral and some sound bright (as well as other characteristics......mostly which CANNOT be measured).
Why? What is the physical mechanism that causes a passive length of wire to have a "sound signature"? If there is a physical mechanism, why can’t it be measured?
How do you quantify "neutral", "bright", "dull"? Compared to what? Hint: you can’t. These are all subjective descriptions with meaning only to you. Others may have a different interpretation, thus, your claim is true for a population of 1- you.
We can measure the objective performance and studies have shown correlation with those measurements with subjective opinions of "quality".
More "you can’t measure it, but trust me"....Praise the lord...
Do I like the fact that the LSA shows more roll off at lower impedance loads?....no, I don’t.