Phronesis
Headphoneus Supremus
Volume is not Everything... My S9+ can easily make HD800S sound super loud, but it doesnt sound good at all.
P.S i think silver cables definitely add extension in both bass and highs and have faster sound, its more conductive after all. Also thicker cables can definitely deliver more bass. Read it from cable manufacturers and heard it myself.
A truly underpowered amp can drive a headphone loud, but it will distort and impact the sound. Once you have enough power, amps should sound the same unless they introduce their own 'coloration' (i.e., particular types of distortion).
I've never seen good data indicating that cables significantly and objectively affect sound, but expectations can certainly change how things seem to sound.