OK, so 80Hz is the 'no-brainer' point. Nobody is going to complain about localized bass if they follow THX. That makes sense.
If I understand you correctly, the way the room interacts with the soundfield will have an effect on how/when bass localizes so its different for every room.
Here's the thing. It seems there is fairly wide agreement that most of the sound that makes a boom sound like a boom and a thwak sound like a thwak is contained in the upper bass region. I saw a few postings containing time based frequency charts of low frequency events in movies and most of the energy appears to be between 40 and 100Hz with stuff sometimes extending up to and beyond 150Hz.
It also extends down to 20Hz, but I was surprised at how little energy there is below 20Hz.
You hear a lot of complaints about missing bass slam. The solution is always get a bigger sub that digs down low, but it seems that the issue is not really down low and that the issue is with the capability higher up.
Reading the notes from a recent sub get together it was interesting that people were very impressed with some high efficiency pro drivers that did not dig down deep, yet had very strong tactile bass.
Further reading suggests that, unless its a very good driver, there is a trade of between low extension and upper bass performance: its hard to get both.
