The top plot doesn't need a vertical axis scale, the bottom scale is clearly frequency.
You can see the peaks and troughs, it's that that matters.
It's a 3 dimensional plot where indeed one axis is frequency which is important.
The other axis is time and possibly not of importance and seems to have emerged from sweeping the band.
Were narrow noise bands used or was the signal wobbled ?
The amplitude plot is rather important IMO.
I mean it makes quite some difference whether or not peaks are just 0.1dB or 10dB higher than the reference.
Is the top 100dB ? 90dB ? and the bottom... is it 0dB SPL ? 30dB ? 60dB ?
It also matters at which SPL was tested and the circumstances (echoic or anechoic, distance from speaker etc.)
Without that info I see no need of publishing plots or info as it says little to nothing.
I end up making my own test CD which tests any sound system including masking artefacts, because I couldn't find anything like it anywhere.
I call it the "beast" CD, because in a very short time it uncovers all the defects of the reproduction chain with no mercy spared.
Care to share the tests and results ?
Which defects are uncovered that a current measurement suite doesn't ?
Being as the source is generated from a DAW and the results are fed back into it, (with either DPA or Neumann mics), what you see is absolutely what you get.
What goes out is 0dB no changes possible, what comes back is usually anything but.
That is what you are hearing chaps (but I measure that too!!).
Aren't all acoustic measurement systems doing that ?
They know what is sent out and capture what is reproduced ?
What is different with your setup ?
Additionally.
You can measure the amplifier output waveform + amplitude as fed to the speakers, and/or a resistive dummy load, and plot it, so by process of elimination one - minus the other is the speaker system.
What is innovative is doing it in STEREO simultaneously not mono.
Isn't that called a null test ?
I have been null testing amplifiers and cables since I was about 20 years old (damn that's 35 years ago) and made my own null tester back then.
Used stereo music signals for that under real load conditions which differs from test tones.
Somewhere on this site I have a picture of my first null tester.
You get the room acoustic signature by using the same methods exactly, moving the mics from speaker proximity to the so called ideal listening spot. I use it to get plots of each individual element and introduce corrections as I go along.
There will sure be a difference in signal.
How do you solve the length difference between the differt drivers ?
Split it up in bands ?
Do you use anechoic room or reverberant room with fixed layout or your own living room ?
What do you do with the results ?
Base time and frequency corrections on it ?
Any targets you prefer to correct to ?
How do you handle sharp peaks and nulls ? Ignore or correct ?
How narrow are the bands ?
Isn't that similar as to what all digital room correction DSP's are doing and if not why is your approach better ?
Masking tests are by far the most interesting, as it tests for masking one tone behind another in phase, then the masked tone is deliberately phase shifted, resulting in the masked tone becoming audible and moving across the room.
Could you eleborate on this ?
I also made a set of tone sequences which tests people's hearing.
The results of those are considerably more advanced than you get from a commercial hearing test in a shop.
(I went into a shop to check btw).
They generated some serious suprises, because you can plot it all out.
It's very revealing to test sound engineers hearing, because it then generates curves which can't be falsified.
Women simply hear a lot better than men, especially before the age of 30.
2 groups of people appear at extended hearing risk.
1 subject was alcoholic, with serious hearing defects.
In the same family an adolescent girl who should have excellent hearing at her age, showed signs of typical "mp3 deafness" to a range of frequencies between 800-950hz.
That was very worrying.
Hearing tests in shops and from audiologists usually only test the lower hearing limit in the important vocal range.
It says something about that individuals hearing but little about actual hearing loss.
To determine hearing loss one would have to sweep the whole band and have references from younger years.
These tests say nothing about peoples hearing abilities at various levels.
There is another snag here.
One can test ones absolute hearing and test for nulls here and there.
You will find everyones hearing differs, certainly if one also tests for spatial effects using speakers.
That's all fine and dandy but stills says nothing about hearing abilities and level of training nor what those individuals 'focus' on.
I for one can't stand hum and ticks. Am less bothered with low level pink noise in recordings but hate more white noise levels even if lower in amplitude.
For me tonal balance is of utmost importance but to others this may be very different.
Another thing it doesn't account for is the human brain and the way incoming signas are procesed and references are set.
Example: 2 people with completely different hearing and preferences both will hear an instrument (or band) exactly the same and knowing it is real build a reference.
They arguably will hear a different tonal balance and have preferences.
Yet, when they listen to reproduced sound they will hear the same as the reference when reproduction is flat.
Arguably when we change something that idn't detected by person A but is by person B then person B will be the only one hearing the difference.
This could be caused by room, driver or headphone driver aspects.
regradless, both different hearing people will still be able to tell bigger tonal differences when both have had equal training in what to look out for.
My own study was based on how hearing changes before and after playing a musical instrument.
Lots of the results were counter intuitive.
THAT is interesting research I haven't come across.
I would expect instruments, amplitude levels and frequency bands as well as time of exposure and time of day to have influence.
Your final comment I don't agree with.
The whole point of optimised sound systems is they should be AS CLOSE AS POSSIBLE to the original sound.
I agree IF that is ones goal.
People who use tube coloration or in transducers, or tone control or processing to get more personal enjoyment in music I would not dismiss as being erronious in the way THEY prefer tp enjoy music.
There are lots of people enjoying vinyl (I am not one of them) just because they prefer the horrible alterations the original recording has undergone or the coloration of their playback gear and claim to have better enjoyment of music than NwAvGuy type of listeners.
TASTE is what this comes down to though arguably, in a sense of reproducing as close as possible to the original waveform, they are deviating from that signal.
BUT since all recordings are a mere mediocre 'catch' of what once was played the question is whether or not such is needed for 95% of all recordings out there.
Only for a very small percentage of well recorded material one could more or less 'demand' as good as possible reproduction.
A funny side effect of these audiophile recordings are that they usually sound very good on even mediocre systems.
That's why in demos and shops they use that type of music.
Granted on excellent systems those recordings are bliss to 'audiophiles/purists' but will probably sound equally 'good' to most people that aren't 'trained' for this.
One view isn't necesarily 'better' than the other.
In the end... with music and individuals all that is important is that the individual ENJOYS the music.
I tend to think that musicians enjoy music more and focus less on 'technicalities' where people like you (and me) enjoy music more when technical perfection is neared where yet the majority of people on this globe don't really care about quality as long as it sounds the way they like it and the way their equipment looks like.
Hence teh variety of equipment out there and vastly differing tonal balances.
Fascinating subject .. BUT IMO there is no 'right' or 'wrong' unless one looks at it from one certain angle.. even then the right and wrong is only that in the eyes of the beholder.
Tastes differ and don't make anybody wrong or right. They just differ in opinion.
As you can see from what I wrote here, there is a whole world of difference between what measures properly and what people appear to tolerate, which is usually a grossly distorting system.
I have never been more shocked than when listening to stuff in those "hi end" audio auditorium shops selling systems upwards of 100K, when their listening rooms are crap, with speakers not even placed right, with amps that sound horrible, acoustics completely screwed up, and sample CDs or vinyl which are even worse.
I fully concur with the sentiment.
I am just not bothered by it anymore.
Just listen to it and take the possible errors along in my evaluation.
If one knows how 'room effects' can change sound then one can hear 'past' it to a certain extend.
I used to get wound-up by such gross misleading and stupidity myself but have learned that people are just people and really like to be fooled, they just don't want to know it.
Nowadays I just talk along with the 'expert salesmen' and have my own opinion.
I don't vent it to them not even when asked ... why ? they don't really care ... al that matters is SALES and they will say anything to get a sale.
Lighten up, do what you like and let others do what they like and the world looks a lot better.