Do not confuse speaker "rated" power with what you need. Do they play loud enough for you? Any hint of clipping on a loud transient? Cymbal crash etc? Be realistic in the peak level you actually play at. Movie special effects or symphony front row? WHO concert level? ( For the latter case you probably have hearing damage and it does not matter)
You can get an idea by using various on-line calculators that input speaker efficiency, listening distance, desired overhead, etc. Decent understanding, but it does not take into account the effective impedance, and hence current requirement due to phase vs impedance. Some speakers, like the Keff R3 are absolutely brutal and bigger power is needed.
I run my bookshelves in a large room with a 60W MOSFET with a HUGE power supply and filter bank. For fun, I tried my Schiit REKKR (2W) and it did folk music just fine. I also tried my workshop amp, FOSI V3 which is in reality about 30W and it fell on it's face, not for power, but for load variance issues. Well, it is an $80 amp!
You can also give the Hegel power supply some breathing room by putting a good correctly sized cap in-line with the amp input. Depending on input impedance, give a 20 Hz first order roll-off. This will help with reducing compression from transients, though the Hegel does have a decent power supply. Far more critical on a Rotel or something where the forgot about putting in filter caps.
I also support multiple subs. Not for power, punch, or distortion, but for smoothing out the room nodes. A single 12 will play loud enough to bust your ear drums. It is smoothing the response that matters.
Any wavelength smaller than the box dimension is basically omnidirectional. Just to be clear.
FORGET all that, and dump the 160 to me for a couple hundred bucks and buy a 1000W Crown :)