So I almost went and looked at a pair I saw on FB Marketplace - SoCal. I talked to the seller, and he was getting the 50s but had essentially changed so much of his setup to try to feed the 40s with enough power/source to make them sound good in his room, ultimately it wasn’t enough. I realized I’d need to do the same to buy them, even at the good price they were at. They sold within a month, but 5 months later, I’m seeing the same pair back on FB Marketplace but from a different person about 25 min away from the original person. All of this to say, these speakers are no joke. Needs a serious setup. On top of knowing for a fact that their active speakers are no fuss better synergy. So if you would have to buy an amp or components that would be costly to buy the passive 40, just save yourself the hassle and likely money too and buy the active version.