I saw some video of a guy who had a crazy sub system in his SUV and people would get in it for a few seconds and it would literally make them disoriented. I had 3 12 inch subs in my car in high school... that was plenty. Also cringy looking back. I ended up going with Emit 50s for the LR, Emit 25C for the Center, Emit 10s for the surround LR, and I forget the sub woofer model but I was told it was a very good one. I am still running them through an old Yamaha HT 5840 still. I don't need to turn them up much due to the size of my living room. Even with the open concept downstairs they're plenty powerful even at 86 sensitivity and 600 watt receiver.
Gladiator was the very first movie I watched once I had the system connected. Didn't have any issues. I'm not sure what "level" this HTR 5840 is. My parents gave it to me when my last one short circuited in a storm and they were upgrading theirs. I assume at 600 watts it's pretty entry level, at least now. I'm using 16 gauge speaker wire. Dunno if that helps.
Cool, I recall Dynaudio being a pretty good brand, but haven't heard any of their speakers recently. Regarding your previous question on efficiency, the spec is the measured loudness of the speaker when you give it 1W of power when measured at 1meter distance. This means the Dynaudios will be quieter (86dB) vs. a speaker with higher sensitivity (eg 89dB). The reasons for this will largely come down to the speaker design, and it makes logical sense that a larger floorstander speaker with a tweeter and multiple speaker drivers would be less efficient due to having additional circuitry and associated power losses going through additional internal cabling or PCBs. The component choices by each manufacturer will also affect this. For example Klipsch uses a horn tweeter design (which I'm not a fan of), that are extremely efficient and have a high sensitivity rating. Another thing to keep in mind is that dB is a logarithmic scale, so an increase in 3dB actually requires double the amount of power. Another variable is human hearing, where I think 3dB increase is generally recognized as the minimum requirement to actually tell a difference, and a 10dB increase would roughly be thought of as being double the loudness. Generally speaking I think most decent receivers should be perfectly fine unless you are someone who likes to listen at 'reference' levels when watching movies. It can be way too easy to get sucked into the snake oil side of audio, so I wouldn't worry too much about it unless you're seeing issues.
