Side firing bass designs - Pros & Cons?...

Interesting perspectives here. My perspective is similar, with a couple of exceptions.
I have quantified a type of speaker distortion, which I have listed with my attorney, as a theoretical concept paper, which details a new quantification of distortion unique to dynamic loudspeakers. I have up to this point called it, in its working form ADD, or Air Displacement Distortion.
Let me explain.
In creating sound, all dynamic, and electrostatic, to a much lesser degree, but for the sake of comparison punch the air in the direction of the listener. I first noticed the great differences that the Pipedreams had, in presenting bass, with much less apparent (to me) distortion in the deeper bass than many other speakers which have good bass reproduction and bass extention. Their woofers are vertically loaded for those who are not familiar.
In working on a model, I started to experiment by switching from one speaker to another, comparing this displacement differential, since the Pipedreams subs, again, point vertically, and are not punching air in the exact direction of the listener. All the other speakers, of note, in replicating bass tones of say an upright,double bass, accoustic, seem to have an accompanying 'sound' which is not part of what I hear when I hear that instrument; so I concluded that the throw of the woofers (distance they move from their rest position) in the front firing woofers created an apparent air displacement, sound, unique to, and constant with this presentation, whereas the Pipes did not. That led to other comparisons, all of which took hours on end. I have concluded several things, too lengthy to list here, but they are, in essence, and in capsule this:
Electrostats, sound smoother, (albiet obviously less dynamic) since they don't punch the air, therefore, creating this amusical driver air displacement 'sound'. They move the air more like (I am supposing) their real accoustic counterparts, i.e. instruments. Even a concert bass drum is displacing air to the sides, when struck. So rarely is the air 'assulted with such force, than in the bass, and with large front firing woofers.
When we discuss phase coherence, and such, we have to consider that the drum is naturally coherent, even though the sound is loaded to the sides in the room, relative to the listener, assuming that he or she is in front. I am going to do more work on this, but some input would be welcome.
I am sure that driver noise, another, similar issue is also part and parcel of the difference that people report hearing in stats, versus dynamic speakers.
Remember, this, as most audio work is not completed, therefore not emperical, but at this stage suppositional again, at this stage of its development. I think back on the Maggies, with limited displacement (relatively), and similar to stats, and horns,(perhaps) and how different, and more lifelike they can sound...sometimes. The Sound Lab Electrostatic has 22 square feet or air pulsing in phase at all frequencies, for example, but moving air a slight amount, but in great volume (not as it relates to loudness, but amount of here). And regardless of individual tastes, most people love their sound, generally reporting it to be less distorted. This is consistant with the Air Displacement Distortion Theory. The SL's sound more polite, and maybe, less accurate, in some ways, dynamically. Thoughts and ideas are interesting here because of the obvious link to my theoretical work.
Also, one final thought, I owned the Mahlers by Vienna Acoustics, and liked their bass, not for the reasons that some do, but because they did not assault the ear the way some front firing woofs do, again, perhaps supporting this theory. I have many more hours to work on this, to finish a white paper theory, but it is interesting to me to contemplate. On the whole, at this time, I think, and am close to concluding something which may be obvious but rarely spoken of, "Driver Noise", which is part of ADD.
Thoughts? Further Ideas? Grant money?
Larry

Thanks. It took some time, years, in fact to quantify what is so obvious after we 'notice it'. I am pretty convinced that the distortions are of another order, (hence the idea for the paper)and of more significance, than just harmonic distortion, even though what you say is accurate, (usual for you Sean). When I think of harmonic distortion, it is more easily placed than this, since this has been part of our universal listening experience most of our lives. It's funny, but when some people would go bonkers over Stats, or Maggies, over the years, I wouldn't quite understand the magnitude of their objection to that pervasive distortion that drivers were making. I am pretty sure it is several forms, hence the new name ADD. ADD will be a combination of harmonic, transient intermodulation, and on and on...
When I look back, the people who loved Maggies so much, or Stats, so much, were usually newbies, (this is simply my isolated experience, and first hand retrospective observation, not emperical) who did not embrace universal driver distortions like the rest of us have. They only knew that it sounded more 'right'. From that perspective how can I disagree? The MBL's have much the same allure, as well as the original Heil Air Motion Transformer, which squeezed the air, rather than slam it. (I guess finesse wins again in some reality huh?).
I have a lot of work to do on this, but as I think about it,
I was enamored with, (and still am) the Pipedreams speakers for much the same reason, (forgetting bass here for a minute, and degrees of taste and particular 'audiophile bias') since they have 80 plus drivers moving fractionally the distance of typical speakers. Moving what has to be almost at the sonically invisible, magic point of distance from rest position. Think of the relevance of comments we all hear and use, relative to, "effortless" and "lifelike" that we hear in descriptions of well done multiple driver array systems. This is no colossal accident, but further potential evidence of the validity of this driver motion distortion, which I am working on and have (potentially) quantified.
Thanks Sean, your system that you are working on sounds interesting.
Von Schweikert Audio, and I (don't get me wrong it's Albert's baby, that's for sure)have been talking about a system which employs multiple woofers, in two separate towers, (limiting great excursion distance) with 11 drivers per mid/tweet towers, which hopefully will be released at the CES in Vegas, in Jan., 2004. The same thing as some older systems such as the Original IRS (I think it was Infinity Reference System). But back then, with limitations of crossover excellence and driver technologies, (not a criticism just noting the twenty year gap in time/technologies) it seems that they sounded a little confusing. But to replicate that today, with better drivers, that is exciting to me.
Best,
Larry

Yes,
The distortion I am quantifying is not anything like the original signal created, therefore is a whole new form of distortion. Just like harmonic distortion, or transient intermodulation distortion, in amps. But this is created by the drivers. Their amusical, and unique sound is audible, which is part of the premise. That "noise" keeps us from hearing the recording independantly. So, if distortion is defined as "any change from the original..." this is fundamental to that.
You know, I personally have always had some issues with the Maggies and the Stats, but there WAS the better parts of their reproduction that were undeniable. Also, horns, which have colorations, but do not smack the air that we can hear like a dynamic driver...so that change has SOMETHING which we all have grown accustomed to, and we just filter it out. Sort of like television. Someone made a comment to me that: audio in its own way is much more perfect than video. You can actually close your eyes and listen and imagine that you are there, but nobody ever claims that video could EVER be mistaken for the real thing. Say you put a camera on a part of a scene, and introduced the video signal into the equation, and balanced the color, brightness, and everything perfectly; you still could never, NOT NOTICE. I had to agree with them in principal. ALTHOUGH, that really kind of enforces my point about audio; in that we block out the unreal parts. I further contend that this is part of LISTENER"S FATIGUE. The harder our brain has to work to recreate the real thing (a piano through speakers versus a real piano) the more fatigued we get. This is why sometimes our system sounds poor, and other times it sounds great. We are the X factor, our brain's willingness to 'complete' that incomplete equation, or not complete it. Think back, usually when you are mentally fatigued,sometimes that's when if you try to listen, and get in that perfect groove, wherein you can 'pretend' it's real, but your brain is not willing to do so, you just end up turning it off in frustration.
So, this annoying driver 'noise' is always in evidence, we just have 'learned' to disregard it. Bass, being the most obvious of all, because of the displacement severity, was the first place I really honed in on it.
Thanks for reading.
Larry

Was any alcohol involved in that story, you know, the nightly nip? HA!
Larry

Dawg,
That, my friend is an excellent question. The Pipedreams use a proprietary 'series/parallel' wiring configuration which ameliorate the lobing effects which is what you are asking about. Otherwise comb filter effects would cause a disturbing cancellation, pattern, which would make them very non linear.
The designer, who I know, won't talk about it in any detail, and I am honor bound to not discuss it more than I have mentioned already.
I hope this is enough to answer, what I consider to be a very good, and intuitive question.
Best,
Larry

I think the key here is, 'minimized'.
Loudspeakers are all imperfect to me, versus real music.
The pipes do some things really well. Mostly micro, macro dynamics because of the drivers redundancy, plus the lack(make that lessening) of the earlier mentioned driver air displacement distortions.
The designer is tight lipped enough on this that he may have come up with the formula to make his filtering less than previously thought possible. Who knows?
They are great, though, in some ways, not all, of course.
Larry