I was going to reply point by point, but I'll just report here the one thing you said that I think is the crucial point of our contention.
You said:
Doing different kinds of visualizations, filtering or "massaging the data" to be more psychoacoustically meaningful are additional processing steps that happen afterwards, most of which is done in the frequency domain.
That may be. Yes, smoothing of the amplitude response does happen in the frequency domain (how else could it be?), but it's not the first thing that happens. The very first manipulation and what it is applied to determines what comes first. So is there any manipulation before frequency smoothing? And what is that manipulation applied to?
Yes, there's time domain gating and weighting, applied to the raw IR. And that's all I have been trying to explain to you. The raw IR comes before (it doesn't matter if the raw IR itself comes from a DTF/IDFT process used to deconvolve the measured signal generated by a sine sweep type of excitation. The raw FR from which you may - or may not - end up calculating the raw IR would indeed come before the IR, but going through a pass in the frequency domain to calculate the raw IR is not a necessary step, conceptually speaking).
I'm sorry but I'm really getting annoyed by your replies where you change things around in yet another attempt to prove that you're not wrong and sprinkle in more confused statements.
How else could it be done? Well, study signal processing and you will find out.
What you say happens before does not usually happen before. The raw IR also does not come before. I explained it like 4 times now.
Lastly, if you move the goalposts and now set the starting point to after the measurement was done, processed and stored in the form of an IR then of course the IR will be the starting point for any processing you'll do afterwards... and it's still equivalent to the frequency domain data, the FR, as I have also mentioned several times so this persistence on the "IR being first" doesn't even make any sense.
You should have dropped this topic when I had to explain to you that the FR is magnitude and phase, is a transformation of the IR, contains all the information, etc. or when you realized that reflections are contained within it as well.. but instead you decided to attack me instead and allege that I don't know these things. It's sad and wrong.
What matters is the psychoacustic FR, I think we both agree to that. Personally, when I say FR, I do mean FR (both amplitude and phase response), but that's another story...
In some of your responses you did, in others you didn't, but it's fine. I understand what you're trying to say.
Only after you derive a first version of the FR from the gated raw IR, you then smooth it in the frequency domain and that's your psychoacoustic FR... and if you kept track of the phase response too (instead of throwing it away as you seem inclined to do, or at least not too bothered by it) you may even recalculate another IR (this time yes, from meaningful FR to meaningful IR. FR would come first in this final step).
What on earth are you on about? Where have I been inclined to throw away phase data?
I actually spoke out against that - so again the complete opposite of what you allege.
If you refer to any statements I made regarding min phase systems then I have to tell you that you don't understand that in those systems the magnitude-phase relationship is clearly defined and therefore you can throw away the phase data because it is redundant. But headphones are only approximately min phase, as I've mentioned before as well. The closest you'll get is probably with single driver in-ears.
Incidentally, at this stage, rather than the IR, a step response is actually more telling (because it's easier to interpret).
A step response is even more prone to misinterpretation because of how strongly it is affected by non-flat FR in the bass range. Innerfidelity did that years ago and people started reading magical bass characteristics out of such graphs because they don't understand what they're looking at.
I've offered similar criticism against showing IRs for the same reason.
There are better ways to visualize, though even CSDs can be misused and misread (just like the ultra smoothed FRs that some manufacturers provide, but we've talked about that already).
The raw IR comes (or should come.. again, not every measurement software is up to speed with psychoacoustics, unfortunately) before any final response graph you end up seeing at the end (both in the time or frequency domain) that has anything to do with how we actually perceive sound.
Nah, after the measurement software recorded the test signal you could stay completely in the frequency domain for the whole process and produce smoothed FR plots without ever converting into the time domain. If I used your language then I could say "don't confuse the process with the concept", but this whole discussion has turned into a charade a few posts ago so let's just move on.
I really hope this clears the waters.
Yeah, I'll skip over some other things you said, let's move on!
Sure, but find me a software (if it even exists) that uses white noise as excitation and outputs both amplitude and phase response and I'll show you a software that took an unnecessarily complex way to achieve those results. I'm not aware of any software that goes that route.
As I stated a few times by now, white noise as excitation signal is indeed useful, if you are only interested in the steady state amplitude response and nothing else.
The steady state amplitude response is better than nothing, I guess, but technology is way past the point when you would use that to measure speakers and claim it has any truly meaningful psychoacoustic value, wouldn't you say? It wasn't intended as a nasty remark (persecution complex much?). What measurement software do you use? Are you sure you're up to speed with what is technically possible to do, in the field of headphone/speaker measurements? It sounds to me from your replies that you aren't, in all honesty.
Most professional measurement suites support a list of different excitation methods. Some hobbyist applications don't. If all you ever used and know is e.g. REW then I don't fault you.
Regarding you again mixing measurement with psychoacoustics: those are two separate things. And even if they weren't then your statement still wouldn't make any sense because (pink) noise is a better approximation of music than a sine sweep.
Of course your remark was intended pejoratively, you just confirmed it. That has nothing to do with a persecution complex, just you alleging things in an attempt to make me look worse and yourself better. This has been the theme of your responses from the get-go. Of course you don't know what I know and what I don't, what I do, what I used... and it sounds to me that you don't care as long as you're right, in all honesty.
And with that I think it's better to bow out. It seems that you don't need any input on how to better evaluate/visualize measurements having it all figured out already.
