What makes the biggest difference in sound quality?

People who sell speakers , sell speakers  .

The Room is it  . In big city I have found 400$ on up power cables  do help .

+1 @holmz on last post

My observation exactly. Two components and only a list of four other items are in question.

You asked Ted … Quantum Purple’s, and this is after a complete heirloom of AQ’s bought just last year. Order of purchase sequence followed by a two month pause between each for evaluation / progress, if any. Speaker Cables, IC’s and PC’s.

For others it may have been a completely different set of questioning but for me it was quite clear.

A fuse, go figure

It would be easier if the question was a poll for say fuses. (Like, don’t like, don’t care)
Then a different thread for ICs… etc.

Or a poll with the 4 things in some matrix which is either 4^3, or K-choose-N or maybe is 24 ranked options? (I would need to take off the shoes to do the maths)

But I like multiple choice questions as they are easier to sort and analyse, than open ended essay questions.

System matching is the most important aspect of great sound. Having a system of equals works in harmony with everything else. Pairing a expensive pr of speakers with less than electronics results in frustrations and miss guided assumptions that some how the speakers are flawed. With this example your assuming the speakers are the fault because they sound less than perfect; when in fact their level of resolution exceeds what your other components have to offer. Balanced system is the key. 

I think quality speakers make the biggest difference. I know folks will go on and on about amplification, source, etc., but speakers have to be quality or the sound falls apart.