Who said anything about me having a system like the one I described? FWIW, I don't. I listen about 10dB below reference in my great room. However, I do plan to put something you would definitely consider excessive in my basement HT that I'm getting ready to start construction on.
I did car audio for over 20 years- I don't think I'll consider it completely excessive. I also had a pair of EV 30W woofers in a fairly small room and didn't think that was excessive, at all. It was actually very well balanced and Holy Crap!, it went lower than anything I have heard, effortlessly. It wasn't like a rap system, it just hit every frequency. I only wish I could have brought them into this house.
I could feel the helicopters from 'The Wall' outside while I stood outside.
If anything, having this number of subs and being able to reach those frequencies is great but I'm not sure how much software contains info in the sub-20Hz range unless it's a test disc, caused by distortion or special effects. For a studio to put information in that range without stating it is irresponsible, at best. A system that can't reproduce these frequencies to the point of audibility wastes every bit of power demanded of it and can damage the speakers in the process- it's no different from playing a warped record without a subsonic filter and I don't know of anyone who would want to do that on a system that could actually reproduce it. This also means that, because they would be catering to less than 1% of the audio market, there's no reason to put anything there. I'm also pretty sure that there's less than a handful of recording studios that can reproduce these notes and if they can, they're not using this ability because most master for smaller speakers.
If you have other people living in the house, I would honestly consider completely separating the music/theater room from the rest of the house. I would also isolate the room from the foundation. This would also be the perfect opportunity to use non-parallel walls, in order to minimize standing waves.
