Originally Posted by DS-21
I don't think you're correct on either of your last two points. His position on BM is conditioned on using speakers that work with his theories, which is to say large cone-area, high-efficiency, closed-box mains with reasonable LF extension (into the modal region, say at least down to 100 Hz anechoic loudly, cleanly, and with low compression) for mains.
Which means Dr Earl Geddes theories are not applicable to 90+% of people on planet Earth since I think it's reasonable to assume that 90+% of people on planet Earth don't
own sealed main speakers.
And while he's changed his approach based on subsequently-acquired knowledge - which is what one would hope anyone would do, right? - the fact of the matter is his old approach (run the mains with no LP, cross the subs up high using an "LFE+Main" or "DoubleBass" setting on the AVR) works damn well with most program material.
That idea just sounds barbaric. You are needlessly
increasing distortion by using the LFE+main, whether your mains could handle it or not, since an argument could be made that the speakers would be better off without it.
As for "full range speakers," pretty much by definition nobody can make a reasonably sized speaker that plays at high, uncompress SPL from DC-20kHz.
Claiming a speaker is 'full range' which hits down to 50 Hz is simply asinine for so many different reasons. You literally have to redefine the word 'full range' to such an extent that it loses all meaning and value. Even if you don't agree that 'full range' encapsulates LF content down to 20 Hz (and below), you have to at least
agree that 'full range' is whatever content is covered by speakers set to 'large', and that is anywhere from 5 Hz to 20 kHz. Obviously the Summa can't handle that, and it certainly isn't 'full range' by most peoples definitions, therefore it isn't 'full range' by most peoples definitions. Only Dr Earl Geddes will claim that his pro-audio speakers are full range which is a contradictory claim in and of itself.
And such a speaker wouldn't even be that useful.
Of course it would be ! The more sources of low frequency reproduction the better
, remember ? That was Dr Geddes mantra. His slogan. His signature. The more LF sources you have in a room, the smoother the response will inevitably be.
However, I agree with you that a 'full range' speaker would be useless.....for HT applications if you use several dedicated subwoofers, since the same speaker would be better off having it's LF capability nuked and high passed to a capable subwoofer that could
handle such levels with lower overall compression and at higher overall levels.
So being able to get stupid loud cleanly at 40-50 Hz - which the sealed B&C woofers in his Abbey and Summa certainly should be able to do!
I don't agree that the 'Summa' can play stupid loud at 40-50 Hz. I would say that the lower limit would be 50 Hz and then, like all sealed designs, act like a high-pass filter below resonance, so 12 dB/per octave below 50 Hz baby ! And the Abbey is less capable than the Summa, so I wouldn't expect great LF response or capability down low. I would expect impressive mid-to-upper bass impact but for a design like the Abbey and Summa, that's par for the course.