Most important component??

Speaker, Amp.

The faulty one!

Beyond faulty components the speakers are by far the most important. They introduce the most distortion and in any system and for a given room may or may not work. Name me any other component that can reduce total distortion by 10% or more.

I don't believe that speaker wire make any difference, as long as it meets basic requirements regarding resistance versus lenght. If the resistance of a wire is .09 ohms over it's length it will make a very small contribution to the electrical path comparing the 6 or 8 ohms of a traditional speaker. Even if it measures .5 ohms it will simply take a little more power to drive the speakers to a given level. There are many articles out there to substantiate this view.

Ron

Single driver speaker running full range with no x-over. Not as good as an optimized wave-guide speaker but considering the trade-offs, a good substitute. Greatly reduces the necessity of room treatments.
My system is in the living room so I can't make it into an anechoic chamber. So beamy single driver reduces room reflections in the H-F. Reflections in the L-F give the bass some body.
2nd would be Jaybo's suggestion of CD / LP quality. Sadly that is out of our control.

For me it's the room&speakers,more the room then anything.My room is OK(14.5'x22').But I know if it was bigger my speakers would really be able to do there thing.

Is the reason CD players, as opposed to Cd/redcordings, rank so low becasue there is relatively little variability in their quality and level of competence to do their job?

The source,always has been always will be.Doesn't matter what you do downstream it begins at the beginning.