^
There is no one correct time alignment at low frequencies because different frequences "arrive" at different times. What can be done is finding the best phase alignment within the crossover region though. And of course there's also the best compromise across multiple points in space too.
There is no one correct time alignment at low frequencies because different frequences "arrive" at different times. What can be done is finding the best phase alignment within the crossover region though. And of course there's also the best compromise across multiple points in space too.
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Yes. exactly my point.
But given the complexities and the challenge the brain has in reconstructing a coherent image from the sound forces of multiple subs, I think we are better off letting the sound remain "natural" without adding false timings from black boxes that are meaningless, arbitrary, and/or non-computable to the brain AND which conflict with all the other position cues. That way, the brain has a fightin' chance of making sense.
This may be what Earl was finding.
(With a single speaker box and/or drivers at slightly different distances, maybe there is some value in time-alignment..... as the tenth or eleventh most important thing to tweak on your sound system.)
Ben
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Markus
No complaint here. In that example the delay works well. I have just not gone to delay as a solution and I have always found a good result.
I am very surprised that both channels benefitted equally by the delay. I would guess that is a rather fortunate coincidence that would not always happen so nicely.
Is there a HP on the mains? That would explain it since I never use a HP on the mains and the phase issues between it and the subs would cause both channels to benefit equally.
No complaint here. In that example the delay works well. I have just not gone to delay as a solution and I have always found a good result.
I am very surprised that both channels benefitted equally by the delay. I would guess that is a rather fortunate coincidence that would not always happen so nicely.
Is there a HP on the mains? That would explain it since I never use a HP on the mains and the phase issues between it and the subs would cause both channels to benefit equally.
Some part is direct, lots is not. For sure, when you think about the kinds of instruments (and halls) that originate such sounds hardly worth fussing over getting drivers with a meter (or more) of alignment. Even if you could figure out how to manage the geometry for even a single seat.
Ben
True, the first curves are horrible. So are the second.Here's an example how adjusting delay improved the crossover region between sub and L (green)/R (red) - upper curves are unoptimized, lower curves optimized:
But here we are getting into the illusion that a freq curve by a mic at one location (when we hear from two locations) tells the whole story of what playing bass instruments sounds like. Again, alignment might be helpful in perfecting a system as the dozenth thing to try.
Ben
Ben
At low frequencies the spatial variation of the sound field is rather small. It all depends on the wavelengths involved - some ten feet at 100 Hz.
I have found extremely good correlation between the steady state LF sound field at the listening position and the perception of bass. It works for low frequencies. Completely different for higher frequencies.
I would say that more often than not, what works at low frequencies is the exact opposite of what works at higher frequencies. That's what makes the transition region so interesting.
At low frequencies the spatial variation of the sound field is rather small. It all depends on the wavelengths involved - some ten feet at 100 Hz.
I have found extremely good correlation between the steady state LF sound field at the listening position and the perception of bass. It works for low frequencies. Completely different for higher frequencies.
I would say that more often than not, what works at low frequencies is the exact opposite of what works at higher frequencies. That's what makes the transition region so interesting.
And Markus76 reduction of frequency response deviation in the crossover transition region from around 17 dB to 8 dB by using delay is not just interesting, it should be easily audible as an improvement.
Right. I got caught up in making my point that the difference is smallish.
Tell me, markus76, would you have preferred if I said, "the first is a trivial badness, and the second is a trivial less badness.?
Which words makes your point? You can't have it both ways.
My view of the first is this: not textbook great but typical of typical rooms. And the second, nicer curve, a bit.
weltersys, you are right to eyeball and report the numbers 17dB and 8dB. But the reality is that the sound processing mostly just took a very little slice out of two very narrow bands and improved the peak of their losses... which tends to be inaudible.
Hearable?
After looking at these curves, I bet everybody (who is friendly to that point of view) would immediately hear gigantic differences in sound. Unless tested blind.
More exactly, I bet for carefully selected test sounds, many people could say the two situations seem different. But I also believe that no little group, present company excepted, could easily agree on what's better or righter.... or couldn't be made to their better liking with an old fashioned tone control.
Ben
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Ben does not "kid", Ben "trolls".
He has been talking about getting DSP, it is possible he may someday time align the rest of his system to the corner horn and actually experience the difference alignment of the crossover region can make, but I'm not holding my breath
. Art
Attachments
Ben,
Time alignment problems are not repairable using tone controls.
Use of EQ when the problem is in the time domain is like polishing a turd, the stink is just spread around.
And I made no personal attack, just observation that you were not kidding, that you were, as usual, trolling.
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I have to agree. He clearly doesn't know what he's looking at and how to relate measurements to perception. That's probably simply a lack of experience?
Ben does not "kid", Ben "trolls".
He has been talking about getting DSP, it is possible he may someday time align the rest of his system to the corner horn and actually experience the difference alignment of the crossover region can make, but I'm not holding my breath
Art
Time-align a big corner horn and mid-room-standing meter-square ESLs... and a giant mid-wall OB sub with a highly irregular baffle board... hope you can hold your breath a long time... or can do the math.
Ben
I use measurement tools for time alignment, and even then, I don't try to hold my breath during the process, which can take an hour or so.
If you would like to hire me to time align your system, and hold your breath during the process, be my guest, but I'll take payment in advance
.Mindless bullying is in bad taste here. If you have no technical point to offer, better save the personal bullying for other forums.
Sometimes anonymous people on the web think they can say things they would never say elsewhere.
Ben
Stick to technical arguments.