I don't think you and I will have any trouble keeping our conversations civil and respectful. And if you do see me crossing the line, please call me out on it!
Thank you for that link, it was very helpful in understanding your perspective. I think there may be a misconception which hopefully I have not contributed to:
A distributed multi-sub system DOES NOT cancel modes! (There IS a technique that cancels modes, but this isn't it.)
And, imo, modes are not the enemy! It is the
relative scarcity of modes in the bass region that causes the major peaks and dips in the frequency response of most rooms which stick out like sore thumbs, and which a distributed multi-sub system seeks to address. This is somewhat counter-intuitive, so let me start out higher up the spectrum:
If you look at an ungated and unsmoothed in-room frequency response measurement, in the midrange and high frequency region the measurement itself looks like grass. There are so many peaks and dips from the in-room reflections that they run together like a field of uncut grass, and effectively form a continuum. They are so numerous and close together that the ear/brain system does not hear them as separate events.
The lower we go in frequency, the further apart and therefore the more potentially audibly distinct the individual peaks and dips become. Somewhere in the 150-250 Hz ballpark (it varies from room to room), these room-induced peaks and dips become perceptually dominant, and this is what we call the "modal region". The larger the room, the lower the frequency at which the room-interaction peaks and dips become dominant.
If the room is large enough, like a concert hall, it has SO MANY modes in the bass region, and they are SO CLOSE TOGETHER, that the in-room measurement still looks like uncut grass, with the reflections effectively forming a continuum, just like what happens at midrange and treble frequencies in a small room. This is a primary reason why bass instruments sound so much better in a concert hall.
With an intelligently-distributed multisub system the net result is a much denser in-room peak-and-dip pattern, which approximates the in-room bass behavior of a much larger room. The semi-random-phase summation of multiple different peak-and-dip patterns reduces the relative size and spacing of individual peaks and dips. No we don't get the "grass", the "continuum" that happens further up the spectrum, but we do get an arguably useful improvement.
Here is acoustician Matthew Poes comparing a distributed multi-sub system to bass trapping in the subwoofer region (south of 80 Hz). This was recprded years before he became a dealer and started selling speakers. He gets his point across in about 30 seconds from where the clip is cued up to:
So a distributed multi-sub system is not canceling out room modes; rather, it is approximating the greater modal density of a larger room.
