... like gravity and Q.E.D... and no one thinks those are actually "real".They're just a theory, after all.
... like gravity and Q.E.D... and no one thinks those are actually "real".They're just a theory, after all.
I do!Do you agree with the above calculations?
I have no problems with squares and no problems with waves, just with square waves. Waves have no corners, squares do.... like gravity and Q.E.D... and no one thinks those are actually "real".
I may well be wrong in my view, I am not an expert in such physical details.
The difference to your view is difficult to describe and very probably formulated "unphysical" or simply wrongly by me. Will try anyway
You are only looking at the time offset of the "wave front" at the temperature-related different sound velocities c1 (343 m/s at 20°C) and c2 (349 m/s at 30°C).
What also changes is the wavelength at a given frequency:
⁁1 = c1/f
⁁2 = c2/f
So something else is happening.
With the change in speed of sound, the time it takes for the sound wave to reach the microphone changes. This means that the "phasor for each frequency" is at a different "position" when the measuring microphone is reached after 5m at a different air temperature. This then causes the frequency dependent phase shift.
The phase shift ΔΦ (caused by change in propagation time) is then:
ΔΦ = 360° * Δt * f
Δt = d/c1 - d/c2 (d = distance)
Here again how Klippel describes the phenomenon:
View attachment 338310
Source: Klippel GmbH
If an expert like @René - Acculution.com is reading this, it would be nice if you could set the record straight about how wrong I am (before I write any more BS? and have to correct countless posts ).
Indeed a real square wave is not really squareI have no problems with squares and no problems with waves, just with square waves. Waves have no corners, squares do.
On a graph, a square wave doesn't look like wave to me, it looks like broken coordinates - anything BUT the wave. Shouldn't appear in nature. And it doesn't.
What confuses me equally, if we look at the graph, is that at the same time point (X-coordinate) there are several points of different intensity (Y-coordinate). How to understand that? Apparition?Indeed a real square wave is not really square
Thanks this is great, it might by like this I buy this explanation .I think Zapper made the right conclusion:
My calculations are all based on let's say an ideal point source. In that case the distance traveled for all frequencies is the same and so if the speed of sound changes by temperature that is also the same change for all frequencies. So all frequency components of the signal coming from the point source will arrive at the same time: waveform will remain the same.
But! In a not ideal sound source each frequency can originate from a slightly different position and can have a different distance traveled to the observer.
In that case if the speed of sound changes this will results in a different delay per frequency component and will distort the waveform.
It definitely doesn't hurt, but physical alignment is not the whole story, since there's usually still a crossover which also introduces phase distortion. This is one reason people say digital crossovers are better.Thanks this is great, it might by like this I buy this explanation .
It also another argument for an idea I had ...
Here it goes for others to scrutinise:
Your better have a coaxial driver when trying to build a “ phase corrected “ speaker ( or what to call it ). This will improve real world use cases as it’s mimic a point source better . It’s not perfect in that’s its not a point it has dimensions . But it’s not two different non point sources which is worse .
It definitely doesn't hurt, but physical alignment is not the whole story, since there's usually still a crossover which also introduces phase distortion. This is one reason people say digital crossovers are better.
With coax speakers I have always asked myself what is the location of the acoustic source of the larger speaker.Ok active coax speakers then
I’m personally not convinced that it’s very audible and how much so given other compromises.
But phase correction is cheaper and works better in active speakers and may not demand so many other compromises that it makes it a fools errand . ( like true first order slopes in the xover )
Anecdotally something audible happens when I activate the phase correction in my kef LSX , but I don’t have the means to determine if it’s a side effect or the actual phase correction I hear it could be either or both . These things stick together so something with dispersion or fr response may also change when this is active?
And why is it an option and not on all the time if it was unambiguously better ?
It usually introduces some extra delay, which you might not want if you're watching videos or gaming.And why is it an option and not on all the time if it was unambiguously better ?
Maybe the extra delay can introduce problem when integrating sybwoofers externaly , not using the speakers own sub out ?It usually introduces some extra delay, which you might not want if you're watching videos or gaming.
For my part when I turn it on/off on my LS60s I can convince myself I hear a difference, but I wouldn't bet much on being able to pass a blind test. You can definitely hear a difference in the moment before the two speakers are both on the same mode, but I bet that's mostly from a slight difference in delay time.
My calculations are all based on let's say an ideal point source. In that case the distance traveled for all frequencies is the same and so if the speed of sound changes by temperature that is also the same change for all frequencies. So all frequency components of the signal coming from the point source will arrive at the same time: waveform will remain the same.
Probably off inventing the first light bulb.The OP seems to be MIA or maybe KIA?
A real square wave is a mathematical abstraction. To actually make one you would need infinite bandwidth.What confuses me equally, if we look at the graph, is that at the same time point (X-coordinate) there are several points of different intensity (Y-coordinate). How to understand that? Apparition?
The OP seems to be MIA or maybe KIA?