Earl has waveguides on his woofers now? I’ll have to check it out . . . 🙄
Consider the case of sidewall reflection. The “apparent” source location will be determined by the “stereo image” formed by the direct sound and the reflected sound (I’ll leave it to you to figure out the relative amplitude and delay of the two for any given wall/room). Now consider a speaker that is directional over one part of its range (no reflection) and omni over another part (direct plus reflected). The apparent physical location of the loudspeaker changes with frequency . . . and you believe that has no effect on the “stereo imaging”?
Point being that it’s not the same even in one speaker when directivity is not uniform. It is the reflections which change it . . .
The room and the speaker are a system. It misses the point to blame the room when the speaker illuminates it unevenly.
+1
Had an interesting experience in that regard a couple years ago setting up for a performance at California Theater . . . there was a high pitched tone coming from somewhere in the hall. It took the better part of an hour to find it . . . it was a "low battery" annunciator in an emergency lighting panel in the upper balcony area. On stage and in the hall it was coming from . . . everywhere. I suspect that had it been pulsed it would have been located in minutes . . .
I wonder if it's easier to locate pure tones outside with few reflections? I've never done the test.
Does anyone know?
Does anyone know?
Don't know why you're saying that. I had responded to this very general statement of yours:
Doesn't answer the question why a uniformly radiating speaker would generally perform better?
That's why acoustic symmetry at the listening position is of utmost importance.
Of course does the speaker and the room form a system. I didn't say otherwise.
But why would a uniformly radiating speaker generally perform better?
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Easier, but ground bounce can still make the location ambiguous depending on distance and frequency.
Indoors, standing waves can actually make the amplitude of the sine wave louder in areas distant from the source.
For days I heard a tone when near the end of my hall like kitchen, it would increase in about the last 1/4 of the room, then be gone when exiting.
I finally got out a portable RTA to see if I was imagining the tone, sure enough it was where I heard it, but there seemed to be no source there.
Wandered around the room watching the tone come and go on the RTA, finally found an intercom "call" switch was pushed on, activating a piezo buzzer in a fiberboard road case at the opposite end of the kitchen some 30 feet away from where the tone was loudest.
The RTA mic could pick up the tone only within a few feet of the box on the floor, the box re-radiated the tone over a large surface area.
Without the RTA, I may not have found the source before the battery died..
We can look back at Pano's files for a clue. For the >700 Hz only pan, there was something wrong. When the entire spectrum was panned, it was completely coherent.
Directivity in the lower octaves eliminates early reflections and gets rid of confusing cues, like in the full spectrum pan. The illusion is more believable.
The LX521 imaged well, but it was nothing like Pano's system. The tone and timbre of the LX521 were much better compared to Pano's. This is surprising because a reflection coming from the direction of direct sound (true for OBs) will be perceived as a coloration in the amplitude response.
You really can't see the connection? You think "acoustic symmetry" matters but the radiation pattern into it doesn't?
I suppose that if you think pointing a directional tweeter at the "far" wall while the woofer reflects from the "near" wall enhances "imaging" you wouldn't . . .
I haven't said that such a scenario is better, I've asked why a uniformly radiating speaker would be better . . . ?
You keep repeating that as if:
a) repeating it makes it true
b) it means something
c) that's what matters
Let go of that notion, and consider more generally what happens when the frequency response (even the presence) of reflections differs from the "direct" sound. The polar response of the loudspeaker has significant impact on that (except in an anechoic room) . . .
You just need to hear such a speaker, Markus. And it will quickly make sense. It's like headphones, except reflections are present, but they are late enough that they can be rejected.
And I've answered . . . it is because (the direction of) the real (physical) source (direct plus reflected) remains constant over frequency.
Could you describe the speakers you heard? I'm not talking about OBs. I would say directivity up to 200-300 Hz, DR ratio of 10db or more, L-R level matched, and you sitting away from boundaries.
That's not an explanation but merely what you believe. Why is it important that "(the direction of) the real (physical) source (direct plus reflected) remains constant over frequency"?