IEM Impulse Response. What does it prove? How does it translate to music?

[Fraxo]

Starting to go deeper thanks to @amirm content, I'd like to understand - what does a faster\slower Impulse Response translate to in regards to Musical content? Does it's shape matter? etc... Is it as controversial or unclear as it seems?

I enjoyed how technical @amirm is and his methods of measuring and perceiving patterns over time, therefore I'm looking to understand how Impulse Response is measured, what we actually know it affects and how to draw conclusions from looking at such measurement.

Will any of you swear by it when it comes to music listening and IEM characterizing?

Thanks!

 

[ZolaIII]

Basically you want that driver response matches the source impulse as closely as possible (ideally). You don't want it to cut before time nor that it wiggles (much) after. For example you want a square wave response to look as much as possible sqere to simplify it.
To musical gernes it translates in tempo (speed), impulses and their decal (how fast it goes down) typical for that sort of music and can drivers keep up with it and how precise of course.

 

[Fraxo]

Basically you want that driver response matches the source impulse as closely as possible (ideally). You don't want it to cut before time nor that it wiggles (much) after. For example you want a square wave response to look as much as possible sqere to simplify it.
To musical gernes it translates in tempo (speed), impulses and their decal (how fast it goes down) typical for that sort of music and can drivers keep up with it and how precise of course.

So accurate representation makes sense, but how could the impulse possibly cut before time?
Also, is that a fact that a shorter decay is more accurate? I ask as it doesn't seem toalways relate to high quality IEM\Headphones models.

And are you claiming that it's undeniably the definition of "speed"? I ask as I see many people ridicule that and relate most to frequency response and THD.

 

[ZolaIII]

Nice citra by the way. Where are you from if you don't mind asking? I used word ideally as it doesn't exist and will be biased between spead and correct time domain. Its related to all drivers and their types (dynamic, electrostatic, planar) and dependent on cone diameter when it comes to dynamic driver's in terms of their physical characteristics and limitations.

 

[Fraxo]

Nice citra by the way. Where are you from if you don't mind asking? I used word ideally as it doesn't exist and will be biased between spead and correct time domain. Its related to all drivers and their types (dynamic, electrostatic, planar) and dependent on cone diameter when it comes to dynamic driver's in terms of their physical characteristics and limitations.

Cyprus
And I must say - the impulse response is still not 100% clear to me, I feel like there's a lot to unravel as far as people disagreement and actual affect on music

 

[dc655321]

I feel like there's a lot to unravel as far as people disagreement and actual affect on music

You mean, with respect to your understanding. Impulse and frequency response have been understood for over a century, but are not easily absorbed without education and immersion, as with most technical areas.

Wikipedia is reasonable first step. But it’s only one of many…

 

[ZolaIII]

I really tried to simplify it (meby even to much). Just read the wiki page and it's far from good explained there. Anyway find more sources and read and try to find actual speaker related examples (like standing next to the larger woofer playing loud) in order to understand it more completely. Best regards and have nice time.

 

[Fraxo]

@dc655321 @ZolaIII
It's exactly what I intend to do, I'll go over wiki...
As you both mentioned wikipedia won't provide all I need - could you refer me to some extra sources which would allow me to reach a more thorough understanding of Impulse Response, FR, THD etc in regards to music reproduction and measurements?

Willing to fully nerd out on it all so I'd appreciate as many sources as you think are at a high level.
As a sound engineer I won't struggle with the material, I'm just not sure where to look in order to unravel the vast knowledge people here have on the technical aspects of hardware and measurements.

I assume you all had a journey of knowledge gathering throughout the years, it feels like it's more of a challenge than the actuall content learning... Some info is probably debatable and some is definite - so another difficulty. Willing to pay for a private session with one of the Pros here for that, but simply pointing out a list of sources in each subject would be highly appreciated.

Thanks!

 

[ZolaIII]

Well there were some discussions here on the forums before so you can start searching from there and extracting what's useful (as there were long discussions). Hopefully other people will direct you and to useful white papers (will be interesting also to me to follow and read). It's good that you will be able to experiment first hand (that will give you insight and more complete understanding). Would have been to hard for me to give you full total juicy examples in English which isn't my first language, that's why I asked where are you from (speculated it's Balkans base on citra hoping we could better understand each other on mother language [privately of course] if it's similar or related but I am afraid it's not [similar, related yes]).

 

[ZolaIII]

Impulse Response from Insertion Loss

This article explains how to convert channel insertion loss data in a standard Touchstone file into the channel impulse response for time domain simulations. It also shows how some pre-processing of the Touchstone data can help improve results by eliminating the ringing that results from the use...

www.signalintegrityjournal.com

 

[someguyontheinternet]

Amir mentioned in a video that impulse response differences are hard to correlate with audible effects.

Around the 14:00 mark here:

 

[dc655321]

As a sound engineer I won't struggle with the material

I'm not convinced of that. Sorry if this is harsh, but:

I don't know what a sound engineer is or does, exactly, but I would have thought signal analysis would be among core competencies.
Or is sound engineer an engineer in a similar sense as IT engineer or financial engineer?

As you both mentioned wikipedia won't provide all I need - could you refer me to some extra sources which would allow me to reach a more thorough understanding of Impulse Response, FR, THD etc in regards to music reproduction and measurements?

Right, wikipedia is not the final word.
But if you don't understand the math there, a "more thorough understanding" will be difficult to grasp.
Like the relationship between impulse response and frequency response, for example...

 

[Fraxo]

I'm not convinced of that. Sorry if this is harsh, but:

I don't know what a sound engineer is or does, exactly, but I would have thought signal analysis would be among core competencies.
Or is sound engineer an engineer in a similar sense as IT engineer or financial engineer?



Right, wikipedia is not the final word.
But if you don't understand the math there, a "more thorough understanding" will be difficult to grasp.
Like the relationship between impulse response and frequency response, for example...

Sound engineer commonly refers to (as in my case) to people who work "in the box" in the digital domain mainly, therefore professionalize in processing audio material, mixing music, editing, etc... It has very complex subjects, algorithms, vast knowledge which I delved into of course, but the world of measurements and hardware details is simply irrelevant.

There are many relevant terms such as the whole understanding of bits, frequency responses and much more, but when I try to associate everything to audio from my domain - hardware and sound recreation were never an issue for my profession as it's an "overkill" information that wouldn't affect my audio work in any practical way.

From past experience - when I do get into learning from a clear source I pick it up relatively easily, but unfortunately with this hardware world the info is scattered, debatable on some cases and I find myself having to pick up crumbs rather than reading\watching clear explanations from top to bottom.

 

[dc655321]

but the world of measurements and hardware details is simply irrelevant.

I am becoming even less convinced of your absorptive properties with statements like that.
An impulse response is an impulse response, whether it be a mechanical, electrical, or digital signal.

but unfortunately with this hardware world the info is scattered, debatable on some cases and I find myself having to pick up crumbs rather than reading\watching clear explanations from top to bottom.

Physics and math do not leave much room for debate.
People do pursue education and achieve careers in these fields, pursuit of crumbs notwithstanding...

Good luck.

 

[Fraxo]

I am becoming even less convinced of your absorptive properties with statements like that.
An impulse response is an impulse response, whether it be a mechanical, electrical, or digital signal.



Physics and math do not leave much room for debate.
People do pursue education and achieve careers in these fields, pursuit of crumbs notwithstanding...

Good luck.

Well I'm becoming more convinced you don't have enough of a clue about what all types of sound engineering entails... In my domain (and I've stated that) Impulse in regards to signal and decay etc would refer to filters, phasing, pre ringing, perhaps transients etc. Measuring it with equipment doesn't seem to have an exact same purpose since it has different side affects and it's absolutely redundant information when going over a certain price range with audio equipment.

I think you overvalue the necessity of the knowledge you posses in real-life audio and mixing work... It's mostly a novelty, which I'm curious about nonetheless as it's in my nature, but by no means is that the focus of all sound engineers.
If you're lacking the experience I posses (which may\may not be the case) - you would not be able to process sound and perform complex audio work, no matter how many stats you can regurgitate. And if you knew what it entails digitally - you'd know how little "noise floor", "THD+N", "Impulse response measurements" and "math" actually matter above a certain price range. YES I know what noise floor is for example, it's relevant in Microphones and other devices, Phase is highly relevant in mixing etc, but the obsession about it in the hardware context makes no sense for practical use, so it's only an expansion I'm personally interested in, and not at all a necessity to be expected.
Frequency Response, Phasing, Sound manipulation etc matters a lot, but differently, so I doubt many would be able to identify and use the right tools to improve and mix audio as an audio engineer in that field would.

I'd put my quick learning skills in "your" domain up against your ability to understand algorithms plugins and sound processing to test how well you'd performs audio work haha.
Would you know how to quantify processing in a multiple instrument mix? How to create\prevent phasing? Avoid masking? Compress accurately? Transient shaping etc.... I can go on haha.
If you happen to come from that field - good on you, if not - you'd probably learn to respect it more if you actually knew what it means and why the type of measurements you talked about are, once again - highly redundant above a certain price point.

I'm thinking - if you pull this type arrogance on me, a professional who can clearly refute what you're saying, imagine how a relatively new person in this realm would be treated.
This is why there's a distinction imo between some community members who are committed to helping and people who are here to flex...
I'd hope to see less of the latter, but this isn't the world we live in is it haha so keep at it I guess

 

[Jimbob54]

 

[Fraxo]

View attachment 196283

lol

 

[Fraxo]

Amir mentioned in a video that impulse response differences are hard to correlate with audible effects.

Around the 14:00 mark here:

Thanks for pointing it out. I guess it's still a mystery then, as he treats it as an almost irrelevant factor and the man has experience...
Not to say that it means nothing, but his perception is interesting.

 

[someguyontheinternet]

It's not just a matter of perception, but also the problems of "can it be verified?" and "can it be quantified?".
While it's possible to perceive differences, if the same effect cannot consistently and independently be replicated, it's simply impossible to verify from a purely scientific point of view.

Maybe my views are a bit skewed from having spent some time in the domain of formal verification in computer science though. It's a field some might call "pretty anal" when it comes to matters of verification.

 

[Fraxo]

While it's possible to perceive differences, if the same effect cannot consistently and independently be replicated, it's simply impossible to verify from a purely scientific point of view.

Are u sure it can't be replicated? I mean if it IS perceived, what makes it inconsistent?
Perhaps it can't be "isolated" for A-B tests, but I'd imagine that if it is creates a certain affect on the sound - then it's a characteristic factor that would be noticeable in ear\headphones according to their respective measurements. Am I missing something?
Maybe my views are a bit skewed from having spent some time in the domain of formal verification in computer science though. It's a field some might call "pretty anal" when it comes to matters of verification.

Maybe my views are a bit skewed from having spent some time in the domain of formal verification in computer science though. It's a field some might call "pretty anal" when it comes to matters of verification.

Haha possibly, I share the same impulse (pun intended) and in my field it made me become more scientific about things that sometimes were meant to be less scientifically examined, so I'm constantly working to balance the two approaches.

I will say that I highly appreciate people like u that are committed to scientific verification, as it sometimes provide the extra hard work most people won't put it.