If you don't have a wide sweet spot, are you really an audiophile?

@audiokinesis /Duke --

What I’m going to suggest is sometimes called "time-intensity trading", as the off-centerline listening locations which have a later arrival from one speaker compensate by having greater intensity (loudness) from that speaker.

Briefly, start with speakers which have a very uniform radiation pattern of perhaps 90 degrees wide (-6 dB at 45 degrees off-axis to either side) over most of the spectrum. Then toe them in severely, such that their axes actually criss-cross in front of the centeral "sweet spot".

For an off-centerline listener, the NEAR speaker naturally "wins" arrival time, BUT because of the aggressive toe-in and relatively narrow radiation pattern width, the FAR speaker "wins" INTENSITY!

JBL aimed similarly with their DD55000 Everest's (DD for "Defined Directivity"):

The design went through a fairly extensive evolution before arriving at the final configuration. Originally, the concept was to develop a "super L300" with a similar sonic character. It was given the working designation of the L400. However, that designation had a notorious past and was soon dropped (see sidebar below). The system would be designed around a new acoustic concept referred to as "Defined Directivity" (the DD in DD55000). This concept had been pioneered by Don Keele in the professional 4660 ceiling speaker. That speaker was intended to provide rectangular coverage with constant volume from front to back. Bruce Scrogin realized that mounting this horn sideways in a home system could provide constant horizontal coverage. The asymmetric design would force more sound to the distant axis compared to the near axis so that someone walking a horizontal line between the speakers would be exposed to a constant sound level.

http://www.audioheritage.org/html/profiles/jbl/everest.htm

The rationale behind this acoustic concept, to my mind, would seem less realized if it didn't entail an appreciation of a sonic correlation as perceived in the seated sweet spot, apart from offering a wider listening area to move within. Image specificity in the extreme doesn't exist in a live acoustic performance, and yet it's a devoured trait in audiophilia. To me at least the predominant takeaway in the debate about a narrow vs. wider spot is honing in on the "sweet spot" between these two dispersive extremes that most closely emulates the perceived impression of a live acoustic presentation, and this also involves for the listener to be able to move from side to side, as one would at a live performance, without seeing the sonic "image" tilt severely.

Image specificity in the extreme doesn’t exist in a live acoustic performance, and yet it’s a devoured trait in audiophilia.

Very important observation....Thanks....

Which observation make me able to say that imaging is important soundwise but LESS difficult to obtain than natural timbre perception in an acoustic settings which perception and experience are the benchmark test of not only sound perception in audio but also of musical perception....

Audio is important but music surpass it, including it .... Electronic is important but acoustic surpass it making it shine or not....

It is MY experience for sure....But the experience of any musician i suppose....

Then the main central concept is no much mainly the "sweet spot" but more the dynamical "envelope " of the sound... One concept is more deep and englobe the other in a SMALL room and this subordination is understood well by any small room acoustic experiments which demonstrate that it is more difficult and ask for more fine tuning of the parameters controls to recreate the timbre dynamical envelope over some imaging ....



If this is true,we could begin to understand WHY we never listen to speakers ONLY in a small room, but to the room itself united with the speakers...


If this is true we could begin to understand why the room could be conceptualize not like a passive set of walls but like an ACTIVATED and ACTIVE participant filled with variable potential pressures zones able to participate and recreate the timbre perception....








«There exist a hierarchy of concepts and of their function. It means that my ass is not less important than my head but serves it, not the opposite»-Groucho Marx

«Is it true for the hierarchy of angels too?»-Harpo Marx

«You bet!»-Chico Marx

«Is this means that economy is the ass and politic the head?»-Gummo Marx

«Are you a communist?»-Zeppo Marx

I once went to look at the Martin Logan Speakers. Don't remember the model. it was in the '90's I believe. The store attendant said they weren't set up properly. I don't know if that was true or not. I know this. Moving my head over 8-10 inches either side, lost the sweet spot. Standing up? Fugetaboutit! Sounded good as long as I sat completely still. Nah, Not for me. 

Great discussion. I wonder if anyone can focus on bass. With Magen pan 1.7 planar speakers I’ve lately focused on bass. Since adding two REL subs I’ve realized how much perception of image and air in a recording comes from the air pressure described in this thread. And since very low bass is omnidirectional, I think it’s more critical to my enjoyment of the system. Also even more critical is bass at lower listening levels. The loudness control. If you have powerful bass at low volumes it’s pretty compelling. I used to have to play everything much louder to get satisfying sound. Now it’s just tweaking the subs a bit. Er, well quite a bit since matching the subs isn’t easy. 

^^ see  ieLogical SubterraneanHomesickBlues for a little insight into integrating subs.

Moving my head over 8-10 inches either side, lost the sweet spot. Standing up? Fugetaboutit! Sounded good as long as I sat completely still. Nah, Not for me.

I doubt I've ever moved my head 8-10 inches either side at a live performance. Or stood up.

Properly set up and integrated, HiFi can do an amazing job at recreating a performance bet it Joe Pass playing acoustic alone, The Who or The London Phil. The trade off, due to physics, is the sweet spot is somewhat constricted.

In a live performance, if one has the ability to wander about, one will find there are gross variations in the sonic field, sometimes in as little as a foot.

It's my experience that a wide sweet spot never elicits comments like "Joe Pass is sitting RIGHT THERE!"