First speaker to reproduce a 60hz sq wave

[Deleted member 48726]

That's what I was wondering a while ago. But this is what I like about ASR, one just needs to start a conversation just passing by and be gone

That's actually okay. The meat is in the discussions. And sometimes a topic is explained in a new way so I actually end up getting (some of) it eventually. I save bookmarks of different topics explained in different ways.

 

[KSTR]

Now comes the crucial point, if the measurement conditions are not changed (the mic and the measurement software are left completely unchanged), a phase shift occurs due to the time offset (because of the difference in the speed of sound at 20°C and 30°C) which "distorts" the plot of the square wave.

I think that's where your misunderstanding is. As long as the speed of sound is constant vs. frequency -- which it is to almost 100% perfection -- it doesn't matter if it is not constant vs. temperature or humidity or whatever. The plot of the square stays exactly the same, except for the different time-of-flight offset.

To avoid this, a fixed time of flight (reference point) is assumed for all measurements (then the correct relative sound generation off-set between the drivers is in the measurements) - for example, the time of flight of the on-axis measurement of the tweeter (and tweeter voice coil as rotation axis for all measurements).
If measurements of the tweeter are carried out and then the measurements of the midrange driver, phase deviations between the tweeter and midrange driver may occur if the temperature of the measuring room increases, as the time of flight is a fixed value.

Obviously you get errors when assumed time-of-flight does not stay constant during measurements with regard to inter-driver phase relationships. But that's either easily avoided in practice or irrelevant vs other errors. IME wind is your worst enemy for far field measurement, especially outdoors.

 

[René - Acculution.com]

Exactly what @KSTR just wrote. If there is no dispersion, you will have your square wave, since a constant time delay does not cause distortion. The only problem you have if there is no dispersion is to assume an incorrect sound speed when eliminating the phase associated with the time of flight.

 

[Adis]

Actually there are conditions where odd amplitude harmonics are all aligned. Certain places are known for this due to currents, wind, and boundary conditions like profile of the shore.

If I did not know that a square is a geometric shape, I would think that it is physical...

 

[Adis]

A real square wave is a mathematical abstraction. To actually make one you would need infinite bandwidth.

It's an oxymoron, in my book.

 

[fpitas]

It's an oxymoron, in my book.

Lol. Well, it is used sometimes in mathematics. No one ever said you can produce one in real life, any more than you can produce the unit impulse function.

 

[ctrl]

Thank you @Hayabusa @Zapper @René - Acculution.com @KSTR for the tutoring...
Will later correct my wrong statements... nobody is perfect

The only problem you have if there is no dispersion is to assume an incorrect sound speed when eliminating the phase associated with the time of flight.

In my example above no one corrects the time of flight after the 10°C temperature rise - it stays always the same, the measurement equipment is not aware of the temperature change, same as my ear.
As I said, first measurement and calibration at 20°C at 5m distance, a nearly perfect square wave is measured. Then 10°C temperature increase and measurement without changes and as you all have now made more than clear to me, nothing changes in the measured square wave.
Because "a constant time delay does not cause distortion".

 

[René - Acculution.com]

There will be a change in the phase related to the change in time delay from a change in sound speed. But it is not really relevant as the square wave is retained. You just go from one constant delay to another (assuming no dispersion) which has the same effect as measuring at a different distance on axis, where the square wave is also seen. This is why the phase related to distance is often desired eliminated to get to the transducer phase.

 

[ctrl]

There will be a change in the phase related to the change in time delay from a change in sound speed. But it is not really relevant as the square wave is retained. You just go from one constant delay to another (assuming no dispersion) which has the same effect as measuring at a different distance on axis, where the square wave is also seen.

Yep, that's where I was totally wrong, as you all kept trying to make me realize, my error in reasoning.
I thought because the time of flight is not corrected after the temperature increase, the phase frequency response is no longer linear (in the measurement) and therefore the square wave is displayed distorted.

 

[Mr. Haelscheir]

Sorry to necro, but this seems like the appropriate place to share and discuss

which someone did link in https://www.audiosciencereview.com/...ilder-line-up-announcement.16835/post-2278823. All that talk about combating IMD and purported Doppler distortion (as far as I can understand from the explanation in the video) when (in my simplified understanding of sound propagation) a mere twitch of your head will incur distance differences from the drivers and hence phase incoherence orders of magnitude worse than said Doppler distortion.

 

[Hayabusa]

interesting! so its a 16 way speaker...

 

[Audionaut]

I read through this thread because it popped up in the news section and I found the headline interesting.

But: Is there a precise description of the technical functionality of the speaker mentioned in the title anywhere in this thread?
I didn't find anything, but maybe I missed something.

 

[Mr. Haelscheir]

I read through this thread because it popped up in the news section and I found the headline interesting.

But: Is there a precise description of the technical functionality of the speaker mentioned in the title anywhere in this thread?
I didn't find anything, but maybe I missed something.

The OP was only really active in the first two pages, most discussion addressing the claim of superiority through being able to "properly" reproduce a 60 Hz square wave. I'd say the video covers about as much beyond what was covered in this thread as someone in the industry would be willing to divulge, which points to it being a fancy 20-way speaker (including the subwoofer; he sometimes uses drivers of the same size, but he did state in his thread that none of the drivers duplicate the same frequency band).

 

[617]

Sorry to necro, but this seems like the appropriate place to share and discuss

which someone did link in https://www.audiosciencereview.com/...ilder-line-up-announcement.16835/post-2278823. All that talk about combating IMD and purported Doppler distortion (as far as I can understand from the explanation in the video) when (in my simplified understanding of sound propagation) a mere twitch of your head will incur distance differences from the drivers and hence phase incoherence orders of magnitude worse than said Doppler distortion.

Love it, totally insane. We're going to miss these guys one day.

 

[kemmler3D]

none of the drivers duplicate the same frequency band)

This sounds more like an exhibit at a children's science museum than a serious HiFi product...

The basic idea makes sense from one perspective... Get rid of IMD/ Doppler, okay... But the trade offs involved in a 20-way crossover... Not easy to manage I am sure.

Maybe it really is amazing? Maybe it sounds crazy? I can't really guess from looking at it.

 

[Tell]

I'm just very sceptical about the whole thing, I mean doesn't the dispersion of each speaker null out towards the sides, but then some of the sound will reflect of the driver above and below it in quite uncontrolled ways?

 

[617]

I'm just very sceptical about the whole thing, I mean doesn't the dispersion of each speaker null out towards the sides, but then some of the sound will reflect of the driver above and below it in quite uncontrolled ways?

Everything about it is insane. The inability of a woofer to stop and start instantaneously was already addressed by an innovation called a low pass filter. I just respect the follow-through. I don't really understand how the whole thing works, to be honest he didn't explain what bandwidth each driver, or are the drivers not playing different bandwidths but different fundamentals and using their own natural distortion to reproduce the harmonic series...

 

[dasdoing]

I mean, if you split a signal into fundamentals and separate fundamentals and than distribute them you don't need a crossover. no clue of course how this thing works

 

[Mr. Haelscheir]

I mean, if you split a signal into fundamentals and separate fundamentals and than distribute them you don't need a crossover. no clue of course how this thing works

To me, it's just taking the concept of multi-way speakers with digital crossovers and expanding it well beyond necessary to be 20-way.

 

[kemmler3D]

I mean, if you split a signal into fundamentals and separate fundamentals and than distribute them you don't need a crossover. no clue of course how this thing works

That's arguably a crossover, just in DSP and to the maximum possible degree.

are the drivers not playing different bandwidths but different fundamentals and using their own natural distortion to reproduce the harmonic series...

I don't think this is possible, lots of music has lots of inharmonic content, e.g. any song with drums. And even if you could somehow use harmonic distortion from a driver to reproduce the sound of an instrument well, it wouldn't work for most other instruments.

Not to dredge up that whole Timbre thread, but the phase of each harmonic compared to lower harmonics affects the sound of an instrument a great deal. Individual harmonics also need to vary in amplitude over time relative to the fundamental. You can't control those things independently in distortion products just using the fundamental.

If you don't actively control every aspect of the sound you can't reproduce the sound. Relying on distortion, as a type of resynthesis engine, even in a very advanced way, would not work.

This is just a 20-way speaker with some confusing marketing flim-flam jargon around it.