However, how much of it is actually under 30 Hz or so? In other words, how much is actually sound that you wouldn't be able to hear out of a set of M80's?
This is a pretty subjective question... It depends on the music. Using a pipe organ CD, like you said, the answer to that scenario would be quite significant.
I primarily listen to classical, there is a pretty good amount of material in the lower range in classical, depending on the composer. Like J.B. said, one of the big factors is the ambient sound. This is where the experience becomes more than just numbers. Sure, the M80's play down to 30hz, with that being said. There is a HUGE difference between the impact of a sub at a given frequency as compared to a pair of towers. I would say impact is the best way to describe the difference. Before my LFR's, i used a pair of M60's for many years. When i added my first 600 it was nearly night and day.. Again, the whole experience like J.B. referring to.
I guess you could liken it to a bookshelf speaker that "plays" down to say 40hz, as compared to a tower that "plays" down to 40hz.. the tower is going to have a whole lot more impact than the bookshelf.. This is where the experience becomes more than just a numbers game... Kind of like your amp experience, on a piece of paper, there "shouldn't" have been a big difference... but the real world experience can be vastly different than the numbers on a page would sugest.
I think i am starting to ramble now... So, i am going to stop with the hopes that i answered your question. If i didn't i'll be more than happy to try again!
