You’re shopping, and it seems you are shooting in the dark. (Which is fine, if that is what you really want to do.)
The general question of what constitutes synergy in an audio system is unproductive. You will get a set of answers that is completely unusable, given the variance in products and listeners.
You need to be specific in using a search for synergy, or "perfect" sound. Focus on one item, the speakers, I suggest, and work from there. Genres of speakers include Panel, Open Baffle, Dynamic, Horn, Omnidirectional, etc. and hybrids of these.
Finally, be aware that unless a person has the capacity to hear hundreds of systems and dozens with a particular product, then the acclamation of synergy or perfect sound is to be weighted as such. Simply because someone thinks a match is good, in no way means it is ideal, or cannot be vastly improved. The systems I built years ago with speakers I would not listen to today. The common factor in the advancement of synergy is one thing, better components and cables, which are often much higher priced. Hence, the question, only partially facetious, $5K, $20K, or $75K synergy?
So, I recommend you hone your search to start with a speaker. If you make the "wrong" decision of the speaker that moves you, then you can have a system with excellent synergy and it still won’t wow you. Give some consideration to this. :)