25% room acoustic
25 % electrical clean house grid
10 % mechanical vibrations resonance issue
15% various noise cleaning methods for the gear
( not so much the choice of cables but first and foremost cleaning the connector and the connection also isolating the component from one another electrically speaking)
25 % only for the gear quality
(Because at the end good amplifier are good and good speakers good with not so much potential differences inside one level of audio quality scale...)
My evaluation is right, " inside" each one of the 3 level of price/ quality scales in audio ... For example exchanging a 1,000 amplifier for a 10,000 dollars one invalidate my percentage ratio... Same for the speakers... If you give me the right room and electrical grid I will make low cost speakers sound like costly one that are located in another not so good room...
I also learned painfully that the best ratio price/ quality product are not necessarily the most hyped and known one ( except vintage one that are recognised legend with time passing)...Most of the times less known products are the best, not the totally unknown product for sure, but the underestimated one by most.......This is my experience paid with my money... :)