Please help me understand

If i take a vision test and have 20-20 vision does that mean I can see colors?

"If i take a vision test and have 20-20 vision does that mean I can see colors?"

no, but you could take this test and check if you do:
http://www.opticien-lentilles.com/daltonien_beta/new_test_daltonien.php

each manufacture when designing amps/speakers/preamps etc - are largely basing their testing on measurments and actual listening - now, depends on the equipment they have available
(the rest of) - it might sound perfect with what they have.
But it does not mean that it will sound same with other combination (for example Accuphase preamp with McIntosh power amp and reverse - just does not sound as good as manufacture match - if manufacture match, then sound is good on both but different). Simply speaking - each equipment has some kind of "equalization/sound proceesing" circuitry that will effect actual output. After that is up to the buyer to decide if they like it or not...
There are sound correction device (like McIntosh MEN220) that tries to compensate for all the equipment/room and make the output more listener "friendly" - but in some cases it can not.
As mentioned before about Bob Carver - yes, it is possible to make 2 different amps sound exactly same using different components - but why? if it was the case, then we would not need all the audiophile forums and discussions.....
so trying to achieve perfect sound by swapping components - it is a endless job, every time we change some component, we gain somewhere and loose somewhere else - but all this keeps audiophiles busy and generates nice profits for manufactures

Rok2id,
Who`s discounting science?it can explain alot but not 'every thing'. Certainly we`re able to detect audible characteristics with our ears that can`t be verified by measurements(yet), Why is that so hard to except. We can measure many things we could`nt 30 years ago and I`m sure in the future we`ll measure things we can`t today. In the mean while we have ears to rely on. Rok2id I`ll assume when you audition and decide to purchase your'audio' components you listened to them rather then just read the measurements and buy based on that criteria alone. Science is great but it does`nt at this stage have all the answers.

"The human ear is more sensitive than any measuring tool."

My post was primarily in response to the statement above. It should be self-evident that human senses, among the animal kingdom, SUCK!! we build machines all the time, to see, hear, smell, and detect things that human senses cannot. We have systems on submarines that can ID other subs by the sound they make. I am sure a machine can be built to ID every amp on the planet, based of that amp's output of a known input. But, who would want to do that? My post may have been an over statement, but if people say they can hear wire and amps and all the rest, FINE! Just leave science out of it.
Just food for thought, your family pet 'hears' more of your high-end system than you do. :) Maybe we need a K-9 audiogon hahahahahah those would be some interesting threads!!
Peace.

Another point not really mentioned much here is that equipment designers do not just use measurements/science, they also use their ears, and they design something that sounds good to them. The vast majority of them understand that it is all about the music and how it sounds, which is ultimately more of an aesthetic choice rather than a scientific one - a choice made with their ears, not their numbers.