I think that the question "what the heck is this all about" is really not any clearer now than it was a thousand years ago. They had their theories which seemed plausible to them as we have ours. We still don't understand the sole existence of the universe any bit more. We can only measure much more now and see a bit more far.
But that's what was the debate about, wasn't it. What would be the other phase effects?
I agree. If and only if you introduce an additional all-pass filter into a full-range speaker that has transient prefect response, or rather flat mag and phase, throughout the full spectrum. And devoid of room.
Have you made all-pass comparisons on such a speaker system?
Like said before, headphones simply don't cut it for such a test imo, due to an inability to impart low end transients.
And, i think any phase audibly test needs to be done outdoors.
Maybe a room masks phase into near inaudibility, and everyone says so what to phase. That's not the point and is not a valid excuse for dismissing phase audibility, imso.
The point is determining the true science of the ears' phase perception, and what is the best testbed we can conceive to discover that.
I've yet to read a phase audibility study that had a convincing speaker/test setup.... and in the right environment, to compare to.
Would love to see any, if other's have....
I won't belabor this any further...as all i can continue to repeat is, so far i don't think we've reached any conclusive science ...
....been more placebo science so far 🙂
I like to see it as the more we understand, the more we realize how much greater there is still to understand.
Yes sir. Must include them all.
I'm kind of surprised anyone would think otherwise.
Flat mag and phase across the spectrum...
Why do we make understanding its various measurement identities so difficult..???
Those identities being, transient perfect; perfect impulse, step, spectrograms & waterfalls; good square waves throughout the spectrum as long as higher harmonics are available....etc.
I don't want to dig any deeper into the "transient perfect" thing in general here either (with DSP you can manipulate the phase both ways - towards transient perfect or towards more phase distortion, and it can be pretty well isolated, IMO). I'm only interested in what's related to horns in particular as perhaps it's still not clear to me what you guys are talking about.
How should long and narrow horns help with this? That is what was mentioned. I see it as almost unrelated.
How should long and narrow horns help with this? That is what was mentioned. I see it as almost unrelated.
I probably didn't follow the "debate." I consider non-minimum phase, such as diffraction, to be a phase effect not related to crossovers.
So the horizon is in fact more and more distant. Seems almost like receding to me... 🙂
Has it ever occurred to you that a staggering amount of 'officially published' (so-called) science, is actually based on fraudulent practices?
A former editor-in-chief of 'Nature' frankly admitted this.
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From that paper:
"All horns present a discontinuity at their mouths.
[...]
A discontinuity in a horn’s expansion produces a reflection. A fraction of the sound power reverses course and returns to the compression driver where it is partially absorbed and partially re-emitted, often several milliseconds late. This process is, of course, regenerative, once again producing a decaying series of arrivals. Low frequencies tend to reflect more strongly than high frequencies, so the reflections are most prevalent in the lowest octaves of the horn’s usable range. It is this precise phenomenon that produces an audible artifact commonly described as a “honk”."
Interesting, who would have thought about that... 🤔
Fortunately it's in fact possible to design horns without such discontinuity.
And of course it can be corrected by EQ (aka a "preconditioning filter"). But it actually needs to be done...
"All horns present a discontinuity at their mouths.
[...]
A discontinuity in a horn’s expansion produces a reflection. A fraction of the sound power reverses course and returns to the compression driver where it is partially absorbed and partially re-emitted, often several milliseconds late. This process is, of course, regenerative, once again producing a decaying series of arrivals. Low frequencies tend to reflect more strongly than high frequencies, so the reflections are most prevalent in the lowest octaves of the horn’s usable range. It is this precise phenomenon that produces an audible artifact commonly described as a “honk”."
Interesting, who would have thought about that... 🤔
Fortunately it's in fact possible to design horns without such discontinuity.
And of course it can be corrected by EQ (aka a "preconditioning filter"). But it actually needs to be done...
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About 1.5 years ago you made a comment in your thread including this phrase "...when this madness is over", remember?
At that time the madness had only just begun, as you probably realize by now.
The apparent horizon is simply created 🤐
This phenomenon, the name of which doesn't come to mind right now (but can be found in your as well as this thread), is described in Markaski's thesis in relation to higher order modes.
It's called resonance. Reflection and subsequent superposition (over and over again).
Worldviews are spread through politics + mass media.
This 120-year-old book is a good start to understanding what I'm referring to.
Attachments
The excerpt from the Gunness paper that you reacted to is certainly not about "astigmatism" (after all it comes from a paragraph called "Horn Resonance"). As usual, I don't have a clue what you are trying to say.
The linked paper presents a case correcting the discontinuities' effects, via FIR filters, not regular EQ (minimum phase).
I don't remember if the paper ever specifically mentions a FIR filter, but ever example in it it is about impulse inversion to fix time domain problems.
Or in the case of crossovers, fix their phase rotation. All that equals FIR loud and clear.
The author, Dave Gunness, is now at Fulcrum Acoustics, and touts what they call 'Temporal EQ', which includes a FIR filter designed to offset horn discontinuities that reflect back from the throat. https://www.fulcrum-acoustic.com/audio-technology-insights-resources/temporal-equalization-tq/
FA offers processing presets for a number of the more common proaudio processors, which include the FIR filters for processors with FIR capability.
https://www.fulcrum-acoustic.com/support/processor-configurations/
So they've actually done it, in spades.
And I routinely, automatically do it.
I think one on the reasons I keep finding it has paid larger dividend to work on processing more than on mouth discontinuities, is that the throat reflections do get mitigated via impulse inversion that spans their relevant time frame. Takes a little work to sort out the wheat from the chafe, but it's quite doable.
Would I do away with any discontinuities if possible before processing? Hell yes, of course.
But it seems pretty clear to me, there's more than one way to skin the discontinuities effects...
To correct a resonance you need to use a minimum phase filter. Both FIR and IIR will work if done properly, that's not so important, both have their pros and cons (I would use IIR). There's really nothing special about it that could prevent anyone from calling it an EQ - technically it's still the same thing.
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