Originally Posted by FOH
Wow, thanks,..all these ideas are swirling through my head as I read your post. I have no reason to believe the coherency of the SH products isn't a strong attribute, but I keep thinking directivity/pattern control is significantly responsible for what you're experiencing. Obviously, top to bottom, it's the sum of all the design aspects that contribute to what a listener gets out of a SH experience. However, I'm just thinking that focusing that energy toward the LP, keeping any destructively smearing early energy off the other surfaces in the room gets way ahead of the room equation from the start.
My concerns are any potential listener fatigue, and the somewhat ragged response in the frequency domain. Are these valid concerns in your opinion? When one views a FR of a normal speaker in a normal small room, the FR @ the LP is highly ragged. Peaks and nulls of 10-20db, and even more are common. This response is an aggregate of the native FR and the room's destructive influences. So, my question is do you feel the SH gets out ahead of this, and it's rough native FR is a non-issue due to it's directivity/pattern control?
Ivan has already made the point about comparing unsmoothed, "hair-and-all" graphs with graphs published from a lying-with-graphs marketing philosophy.
Here is an additional fact: running a TEF sweep through the SM60M's in-room, produced a graph very similar to the graph posted on the Danley site, the differences due to room absorption and less than ideal speaker placement.
To be clear, the peaks and valleys did not always match exactly but the general pattern was very consistent with the ground plane (or hoisted in the air) measurements from the Danley site.
But what was surprising was that the Danley's delivered in-room a very close match to the response posted as its nominal response, that the Danley actually delivered to a real world listener's space a very close approximation of what was advertised!
This is a remarkable achievement, if you have actually swept small rooms with high resolution equipment, not going by the graphs produced from an auto EQ/room correction system. The short duration sweeps that the automated calibration algorithms characteristically use severely limits their accuracy, BTW.
The Synergy design actually shocked me with how close to its nominal response it brought to a severely compromised room. An indication of a superior idea is when it succeeds in the most challenging conditions, not how well it can be propped up by a heroically ideal demo room.
The most notable fact from that live in-room sweep is that it displayed the same characteristic frequency response as the response posted on the Danley site! AND that the in-room peaks and valleys stayed for the most part within +/- 4dB from 200Hz to over 13,000Hz, showed that the speaker's response dominated the room's response, the speaker's directivity and its uniform "illumination" of the space within its coverage pattern providing a more predictable response.
Of course, directivity is an important aspect in a small room. Directivity alone however, cannot explain the coherence by itself. Inevitably, in a small room (HT sized), there WILL be reflections. Unless the room is over-dampened with treatments (try enjoying music in an anechoic space!), there will be late arrivals mixing with the direct waves. In my untreated room, I am delighted that the 4 Danley system's coherence dominates. A room properly treated using diffusers/bass traps would still benefit from this coherence.
I am speculating that the most critical factor that makes or breaks this coherence effect, is the impossible-to-fake, time and spatial alignment of the drivers' output, aiming at reproducing a point-source with directivity.
When the inevitable mixing of direct arrivals with reflections occurs, the hypothesis is that the greater off-axis timbral uniformity AND the original point-source time alignment of the reflected and the direct waves combine to make the convolution by the ear-brain to recreate the original soundscape easier to resolve, by starting with fewer errors from greater coherence at origin.
The last adjective I would use in regard to the SM60M's response would be "ragged"! I can only speak to the SM60F/SM60M and the SH100 models but the words that I would apply would be: smooth, neutral, transparent, musical, efffortless, NON-fatiguing to the max!
My test of a sound system is how you feel after a 6-8 hour immersion session; other than flat-butt syndrome, the 4 channel Danley system has the least listener fatigue of all the systems I have owned.
There is something very important about this true phase coherence in time and space to our audio processing capabilities, that makes what is a self-trained perceptual skill in all of us, the skill of recreating a realistic space from imperfect audio cues, easier to apply, requiring less processing effort on our parts. This extra ease and relaxation translates to extra involvement in our perceptual recreation, the feeling that there is more "there" there!
If frequency response anomalies are considered to "color" the sound, what then does time smear and the disjointed response in time and space of multiple drivers do to the sound?
Slice the sound image into separate chunks like a Benihana chef?
I return to the word coherence as it has a precise denotation in laser engineering and has the clear connotation of every piece of the whole being in sync with every other piece until there is only the whole.
In short (too late!
) it is my conclusion that whatever this coherence is, it is more important to great sound recreation than a "ruler-flat" frequency response. A near flat response UNVARYING from on-axis to all the way to the edge of the pattern is much more audible and of greater impact on imaging and the life of the music than a "flat-on-paper" on-axis response.