I'll put a few cents in on this one
The first and most important thing to remember with time and phase aligned multi-driver arrays is that they are made to sum properly at a certain point(s).
If this T&PA speaker is a 2-way design, there will be a single plane that slices through the speaker at which any point on this plane will be equidistant from both drivers, this is the plane of proper summation.
If this T&PA speaker is a 3-way design, there will be a single ring of points around the speaker that is a certain distance from the speaker. This only holds true if the acoustic centers of each driver are in a single line. If they are not in a single line, i.e. the midrange is farther back or forward, there will be a singular point where the output from all drivers sum properly.
All of this holds true only if perfect first order crossovers are employed, extending at a minimum of one octave past the crossover point, preferably two octaves. There are other ways to do this will 2nd order slopes and filler drivers as well, but John K's site is best for this:
www.musicanddesign.comNow, if you are not listening on this plane, on the circle, or at the point of proper summation, you will have the compounded effects of non-proper summation: 1) frequency response aberrations due to different arrival times at and around the crossover point, and 2) non perfect T&PA.
Also, every reflection off of every surface will have this effect applied to it as well. The two most prevalent things that color the sound reproduced are the mirror image of the speaker below the floor surface and the mirror image off of the ceiling. Lets take the floor for example. In a 3-way system with a woofer near the floor, a midrange centered maybe 36 inches up and a tweeter centered 42 inches up, the initial arrival times at the listener can be all perfectly aligned with first order slopes, but the reflection off of the floor will be totally out of whack. The path length for the woofers reflection will be very short, the midrange longer, and the tweeter longest. The same goes for the ceiling reflection, but in reverse order. The reflections will all have the colorations of the off-axis response of the driver then filtered by the reflective properties of the surface they reflect off of.
Listening to this speaker what you will hear will be: (Bar | denotes time delay, brackets [] denote frequency response abbaration due to floor reflection and off-axis response, braces{} denote frequency response abbaration due to ceiling reflection and off-axis response)
Woofer Midrange Tweeter | [woofer] | [Midrange] | [Tweeter] | {Tweeter} | {Midrange} | {Woofer}
You get the idea....
It is my opinion, that a much more balanced, coherent, sound can be had when designing with much more attention paid to off-axis response smoothness, lack of cancellations in the off-axis, and having the same time coherence at off-axis angles.
The Ronin 1.0c does not use first order crossovers, so phase coherency is not possible, however, the disc, ring, and point analogy above can be expanded to almost any point that is less than about 70 degrees off axis with regard to proper arrival times for proper summation in the crossover region.
This also means that all reflections arrive at your ears properly, and not skewed in the time domain like other phase and time coherent speakers.
The Ronin 1.0d with its linear phase digital crossovers is time and phase coherent on and off axis with the same foundations for even power response in the Ronin 1.0c.
Odds are pretty good that if you have really liked a T&PA speaker before it was just a plain old good crossover design, with good drivers, good cabinet etc. The only time the T&PA really holds true when you aren't in an anechoic chamber is with coaxial drivers combined with first order slopes or linear phase digital crossovers.
Hope this helps and properly conveys my opinion on the subject since it originally asked for manufacturer input.
Regards,
Paul Hilgeman
Nomad Audio
P.S. The Gravy thing - Well Said
