It was largely accurate, it just reeked of a sales pitch or AI.
It just reeked of 'not what we want at ASR' to me.
We have plenty of real intelligence here.
It was largely accurate, it just reeked of a sales pitch or AI.
Slight correction: frequency-dependent phase is normal and is not directly equivalent to group delay; group delay is the (negative of) the change in phase over frequency. If the change in phase over frequency is linear, then the group delay will be a constant (single number), and all frequencies will be delayed equally.The technical term for “frequency dependant phase” is “Group Delay”.
Slight correction: frequency-dependent phase is normal and is not directly equivalent to group delay; group delay is the (negative of) the change in phase over frequency. If the change in phase over frequency is linear, then the group delay will be a constant (single number), and all frequencies will be delayed equally.
HTH - Don
Only if it were that easy. I could not yet find a single tool that unwraps phase correctly for all possible impulse responses and Matlab's unwrap is one of the worst.you unwrap phase
Agreed! It gets especially bad where there are multiple wraps between measured points.I could not yet find a single tool that unwraps phase correctly for all possible impulse responses and Matlab's unwrap is one of the worst.
This is true. What I've found is that you're usually fine as long as you exclude any part of the phase response that has close to no energy in the spectrum.Agreed! It gets especially bad where there are multiple wraps between measured points.
Reading this and trying to understand all the different terminology and theory and possible issues is challenging and makes me want to try some speakers with first order crossovers. I know that higher order crossovers are easier and the mechanical requirements of the drivers much lower so much cheaper drivers can be used, but if modern materials and engineering were applied to the drivers and the enclosures and the wave guides would it really be that much harder and more expensive? Seems like first order filters eliminate a lot of potential issues and problems. Unless of course the OP is correct and phase does not matter.
Interesting, how does that work if a first order filter doesn't change the phase of either signal of a pair? It make sense to me that mechanical differences in the drivers could cause relative phase changes but electronically it seems like they should stay in phase? Filter theory reminds me of thermodynamics where intuition is not helpful.First-order crossover filter pairs are also not in-phase at all frequencies.
Here is a simple first-order crossover with low-pass (LP) and high-pass (HP) filters at 1 kHz. The HPF starts at 90 degrees falling to 0 degrees at high frequency, while the LPF starts at 0 degrees and falls to -90 degrees. The phase is not the same though the slopes are the same.Interesting, how does that work if a first order filter doesn't change the phase of either signal of a pair? It make sense to me that mechanical differences in the drivers could cause relative phase changes but electronically it seems like they should stay in phase? Filter theory reminds me of thermodynamics where intuition is not helpful.
Their sum (at least with one of the two choices of polarity a) s+w0/s+w0 and not b) s-w0/s+w0) is exactly one with zero phase. So in total, the phase is unchanged. It is often said that you can only do this with first-order, but that is not true. You can do it to any order, but as m-way, meaning no longer two-way.Interesting, how does that work if a first order filter doesn't change the phase of either signal of a pair? It make sense to me that mechanical differences in the drivers could cause relative phase changes but electronically it seems like they should stay in phase? Filter theory reminds me of thermodynamics where intuition is not helpful.
How about fitting a 3D Heyser spiral curve based on the magnitude and phase of the target transfer function?Exactly, which is why I say endlessly that you unwrap phase, then do a first-order fit, and subtract that out. The remains is the frequency-dependent part that is not pure delay.
That simply shows the phasor with its time dependency multiplied to it.How about fitting a 3D Heyser spiral curve based on the magnitude and phase of the target transfer function?
View attachment 399934
That simply shows the phasor with its time dependency multiplied to it.
In my opinion, absolutely yes to this point, as this was my own experience, being highly critical and "knowing" that this should not be audible. When several instruments had to 'hit' (whatever the musical term is) at the same time, you could hear them "in-sync" in one setting (Kii3s, phase linear), and not in the other. Very subtle, yet something that made all the difference in the blind test, and perhaps something you could grow sensitive to(?).So maybe you could spot a single passage there phase shift is pronounced, even in a very, very subtle manner.
Phase is tricky to understand. Perhaps this helps: https://audioxpress.com/article/simulation-techniques-misconceptions-in-the-audio-industry
It is tricky, byt your example points to a miniscule difference in presentation. So it just might be itIn my opinion, absolutely yes to this point, as this was my own experience, being highly critical and "knowing" that this should not be audible. When several instruments had to 'hit' (whatever the musical term is) at the same time, you could hear them "in-sync" in one setting (Kii3s, phase linear), and not in the other. Very subtle, yet something that made all the difference in the blind test, and perhaps something you could grow sensitive to(?).
Regarding phase, all of the information regarding delay is hiding in it. If there is any 'strict' delay in a system, there will be a corresponding linear phase. This goes into the so-called Excess part of the phase, that might contain some other non-minimum aspects. They add up, as I illustrate below, where the excess phase from a LR4 filter (allpass system) can add to the phase from a delay and make up the total phase.
View attachment 399974
Phase is tricky to understand. Perhaps this helps: https://audioxpress.com/article/simulation-techniques-misconceptions-in-the-audio-industry