"Arny Krueger" ..
"Phil Allison"

** Hang on Arny, what multi driver array has the 901 really got
?????

The answer is none. There is only ONE driver facing the
listener.

You are mixing the 901 up with the 802 PA speaker.

Phil, what are those two arrays of 4 speakers on the back of the
901? Or, am I imagining that I saw them there?

** Oh come on Arny !!!!!

OK, so we agree that there are in fact two arrays of 4 drivers each back
there, right?


** That is a red herring - Arny.



There is no significant "lobing and comb-filter effects" with a
driver array that is **NOT** facing the listener - compared with
one that is.


In most cases the back drivers on a 901 are facing a smooth wall. Lobes
bounced off a wall are still lobes.


** The lobes are spread way out by the off angle reflection and lost to
the listener.

A listener seated in the usual central position could not detect them.



Furthermore, there are those oddities where the array has a critical
distance,


** Define your terms, please.


This affects 89% of the sound coming out of a 901, if Bose is to be
believed.


** The "Hass" effect plus the extra proximity and brighter sound of the
forward facing driver normally makes it the apparent source for a centrally
positioned listener.

The other rear facing ones will produce a delayed and duller sound -
depending on the nature of the walls, distance away and their coefficient of
absorption at various frequencies. If the walls are far away and
acoustically dead then the forward facing driver dominates strongly.

The "lobing ... effects" are only going to be audible if the listener
moves their head in the direct field where the lobes exist - ie behind the
901.

The "...comb-filter effects" are audible where rear wall proximity and
reflection of sound creates them - it is not due to the way the drivers are
arrayed.

IME both the 901 and 802 suffer from *gross* IM and Doppler distortion at
high SPL levels - nauseatingly so to my ears.




............. Phil