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

A lot of these so called true audiophiles think fuses, wires and speakers that have a FR that looks like the snake river provide the best listening experience. Give me a pair of Genelec the ones set up right and you can have a wider sweet spot than the size of your head,  sacrificing nothing.

By way of background: The ear localizes sound by two mechanisms: Arrival time, and intensity. If the arrival times from both speakers are identical, the image will be shifted towards whichever speaker is loudest. And if the intensities are identical, the image will be shifted towards whichever speaker’s output arrives first. With conventional speakers, as you move off to either side of the centerline, the near speakers "wins" BOTH arrival time and intensity, thus the image shifts towards the near speaker, often dramatically so.

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.

I will use your excellent post to illustrate a listening experiment of mine suggested by this japanese article research to me... Adding then to your information the idea of 4 critical thresholds linked to LEV and ASW...



https://www.researchgate.net/publication/223804282_The_relation_between_spatial_impression_and_the_l...




My experience is simple and improve greatly the " imaging" but also the "encompassing sound effect " factor or the auditory source width (ASW) and the listener envelopment (LEV)

I use small Helmholtz pipes of the right volume and neck ratio near the tweeter and near the bass driver but in an asymmetrical fashion between the 2 speakers... One speaker tweeters is linked to 2 Helmholtz  different pipes near the tweeter, the other not.... One speaker is linked with the Helhmoltz  2  different pipes, near the bass driver not the other speaker... The difference of timing of these frequencies between the 2 speakers illustrate this 4 thresholds law which spoke about the japan scientists... This experiments is mine and not in this article...

The effect is huge and explained by the japanese article on the law of the first wavefront linked to their 4 tresholds law in audio....

This is my last experiments and device... I will put it in my audio thread: "miracles in audio"... Where i described my audio journey...

COST: PEANUTS...

Effect: imaging way better and also better timbre....

Conclusion : imaging is not ONLY the result of  the structural electronic engineering of the speakers like suggested in this thread erroneously and ONLY their location , but first and last mostly the result of the law of the first wavefront and of their 4 tresholds in acoustic...


I will repeat the definition of Toole of the law of the first wavefront in his main work :

«In audio in the past, the terms Haas effect and law of the first wavefront
were used to identify this effect, but current scientifi c work has settled on the
other original term, precedence effect. Whatever it is called, it describes the
well-known phenomenon wherein the fi rst arrived sound, normally the direct
sound from a source, dominates our impression of where sound is coming from.
Within a time interval often called the “fusion zone,” we are not aware of
reflected sounds that arrive from other directions as separate spatial events. All
of the sound appears to come from the direction of the first arrival. Sounds that
arrive later than the fusion interval may be perceived as spatially separated
auditory images, coexisting with the direct sound, but the direct sound is still
perceptually dominant. At very long delays, the secondary images are perceived
as echoes, separated in time as well as direction. The literature is not consistent
in language, with the word echo often being used to describe a delayed sound
that is not perceived as being separate in either direction or time.Haas was not
the first person to observe the primacy of the first arrivedsound so far as localization in rooms is concerned.»

Sound Reproduction The Acoustics and Psychoacoustics of Loudspeakers and Rooms Floyd Toole Chap.6 P.73

Anybody who thinks they have a wide sweet spot either does not know how to evaluate an image or has no sweet spot at all. High frequencies blasted all over the room does not constitute a sweet spot. It is all about the image not dispersion. 

@misogyn,

another completely useless post, that. You excel at harping without contributing

I don't agree with that mijostyn.  Imaging comes from both volume cues (predominant in most multi-channel studio recordings by far), and timing from a proper stereo microphone setup which is rather uncommon.  This is a long post, but all relevant.


With good dispersion and non-symmetric toe in, you can get reasonably accurate volume cues over a wider range.  That provides two significant mechanisms for location,  1) Relative volume level,  and 2) Frequency dependent head shading. 


What you can't compensate for is timing, but there are two issues, a) Was timing even captured, and b) Can timing be conveyed with speakers in a traditional two channel audio setup, both because of the extreme accuracy needed in head placement, and the inability to prevent sound from one speaker reaching the opposite ear.

0.1" of head miss position = 1. 6 degrees of timing inaccuracy0.5"  = 8.2 degrees2"  = 32.7 degrees


So lets say you are sitting 10 feet back from the center line of your speakers at 60 degrees. A 2 degree toe-in difference only represents about 3.8 degrees of image movement, and the movement will be true for all sounds. I.e. the image shifts left or right.  If the toe-in is symmetric, 3.8 degrees represents moving your head left-right about 3".  At 5 degree toe-in difference, you are looking at 10 degree offset, and about 7" of side-side head movement (14 inches total range). You just moved from the best seats, to pretty good seats.

Of course much of this is all literally fuzzy anyway. When you have your speakers at 60 degrees, head shading to both ears creates an improper center image. You may have recorded timing information, but because you have no cross-talk cancellation, you have a secondary timing event about 0.2 seconds later confusing the brain on whether that is the event, an echo, etc. The singer (continuous tones) are properly placed, but perhaps a bit fuzzy due to aforementioned issues of shadowing for volume, and the drum hit off to the side, gets confused in the false secondary timing event.

Oh, so it is easy ... ya no. There is one other huge issue in capturing timing difference in stereo microphones. You are now playing back the same signal delayed in time between two speakers. Guess what that does when it hits the head?  Filtering!  Comb filtering effects will be evident and significant as the fixed timing delay reinforces and cancels depending on the frequency.   Oh, but it gets even better ... I mean worse. Where timing only contributed spatial cues at <1,500 Hz, those new comb filtering effects you generated are now across the frequency range. You think you widened the stereo image, but really you created an auditory illusion of space that is not representative of the timing recorded.  The timing becomes a level difference perception.  *** Note that now, head accuracy becomes far less critical ***


And just to be clear, stereo speakers attempting to reproduce timing can't place the image outside the speakers (see crosstalk above).  Of note also, timing only really works at <1,500Hz, and predominantly <1,000Hz.  So to all those "phase" "phase" "phase" people, less posting, more learning, and for those buying or making speakers, keep the crossover out of the 200-1500Hz range if you can.

So what can be done?
- Signal processing akin to noise cancellation, but in this case, to reduce cross-talk
- Headphones with signal processing to replicate the body functions (head shading, reflections, etc) that are lost without an audio field.