I don't think the first two posters understood the question. It sounds like you did actually change something (speaker placement). That might be responsible for the improvement you hear.
Upgrade phenomenon
What do you call the improvement to your system that you get after you’ve made a new purchase, but before you’ve even received the new component, speaker, cable, or doohickey? I shifted my speakers a tiny bit. I looked at the GIK website and took some room measurements to investigate room treatments. I bought my first new tube power amp after months of agonizing and research and saving spare change (and maybe a little embezzlement, but that’s a secret). I bought some new cables. But I haven’t changed anything yet, just placed the orders. Is my system just happy because I’m finally giving it some TLC and buying it presents?