planning a "macrodynamics" in headphones experiment

[someguyontheinternet]

Motivation:
The topic of "macrodynamics" has come up in the DCA Stealth thread and I would like to investigate this a bit more. To do so I require some information so that I know which products and what musical content I should include in my experiments. The same topic has also come up at the thread at headfi so I was also able to gather some information there.
These kinds of fuzzy topics always annoy me until I manage to mentally wrestle them away or exert enough effort into research to calm my anxiety.

Hardware setup:
From what I have gathered so far it appears that Focal headphones are supposed to excel at this quality while DCA headphones are supposed to represent a lack of this quality. I will focus my initial experiments on the Focal Elex and the DCA Aeon RT closed since I already own these. An added benefit is that Amir has measured both of these headphones so speculations for the source of this quality can be based on existing measurements.
As recommendations for headphones come in I will check which of them I can test at local stores (or buy for myself if I like them). However since my resources as a single person are limited I would like to invite others to replicate my experiments, if they have the resources and time to do so.

I'm planning to use the RME ADI-2 DAC using XLR interconnects into a Monolith THX 887 with the single ended output (since I don't have balanced cables for DCA and Focal). After initial experiments I can also go the extra step and pick up some XLR terminated headphone cables as I was planning to do so in the future anyway. I believe that this setup should be sufficient to guarantee that the headphones will be by far the most contributing factor to any "coloration" of the sound in my assessment.

Playback setup:
I am planning to use Deezer HiFi on my Windows PC or CD files (if I can find some) for playback. I'm not quite sure if it can be argued that going beyond 16/41 may make an impact so I also want to ask for input on this aspect and will adjust my plans accordingly.

Arists that have been mentioned at headfi to check for this quality are Marian Hill and Joni Mitchell. Since this is a relatively small sample size, but easier to vary than headphones, I would like to especially request more examples for test tracks/artists.

I want to test both with stock tuning and EQd with Equalizer APO using the AutoEQ settings.

I'm not quite sure how I should approach listening volume as the Elex seems to distort a lot more at 114dBSPL. I will stay far below that level for my initial tests at least.

Closing:
Lastly I am just a (relatively) normal guy with an interest in accurate music reproduction. I don't have particularly trained or "golden" ears and I think that I should be reasonably close to the "average" listener.
Any input is greatly appreciated and I will try to incorporate feedback that I can reasonably accomplish given my available time (not a lot) and resources (enough for a couple of reasonably priced extra pickups).

 

[solderdude]

I don't feel Focal headphones have more 'slam/oomph/punch' than DCA headphones.
My P.O.V. is that it has to do with headphone sensitivity.
The DCA is notoriously inefficient and you need to turn up the volume a LOT compared to the rather sensitive Focals.
So when plugging in sensitive headphones and DCA for instance you have to set the volume to other settings.
A lot of smaller amps will not driver the DCA so loud you can make Amirs earlobes shake while efficient headphones will.

That doesn't mean some headphones do not sound more or less dynamic than others. There definitely are differences.

And another thing... what needs to be established first is what which reviewers describes as what kind of thing.
Dynamics in electrical, digital, studio and perception are not describing the same effects.
That needs to be set in stone and agreed upon IF this is an attempt to quantify some descriptors.

It is a similar effect as people claiming high gain settings sound more dynamic than lower gain.

So.. its a fun experiment but one would have to measure SPL for this to mean anything.
Once you have the idea something sounds a certain way your brain will surely help you.

This is the problem between any subjective finding and measurements.

I do get various headphones to measure and often when listening to them the first impression often is not the same as a later impression or after time getting used to it. Opinion later on can still vary when having listened to another one for a while.

Subjective opinions (slam, punch, and whatever other nice description) are dependent on many factors. That's the reason why there is no (or little) hard correlation to measurements.

This basically also is the whole discussion between Amir and Resolve. I get both their standpoints. Both make sense. I agree with both.
Amir is of the standpoint (just like Rtings) that one should only look to measurements to evaluate. Resolve does both but relies more on impressions in his review. Amir to measurement facts.

I am in between. I measure and listen but rely more on measurements. The reason for that is the same as Amir. You can't trust impressions. Regardless how good one is.

For instance, Tyll made videos, so do many others like Z etc. I also heard quite a few they review and the few reviews I have seen of headphones I know or tested are not the same. Not even between reviewers. So take impressions for what they are.. personal findings. You may agree with some, you may not.

Facts are 'facts' also isn't fully true either. Measurements made on the same rigs often correlate well (when done correctly) but between setups they don't. Let alone target curves and interpretations as well as seal influences and positioning on the head.
Also these 'facts' contain errors and not everything that may require specific tests are done (correctly) either and maybe some test protocols (signal types) for electrical equipment is less suited for acoustical and maybe some tests still have to invented or improved.

In short: correlating measurements to perception often is impossible to do due to the brain/ears/gears/conditions/individuals/tastes/recordings used.

 

[Zensō]

I don't feel Focal headphones have more 'slam/oomph/punch' than DCA headphones.
My P.O.V. is that it has to do with headphone sensitivity.
The DCA is notoriously inefficient and you need to turn up the volume a LOT compared to the rather sensitive Focals.
So when plugging in sensitive headphones and DCA for instance you have to set the volume to other settings.
A lot of smaller amps will not driver the DCA so loud you can make Amirs earlobes shake while efficient headphones will.

That doesn't mean some headphones do not sound more or less dynamic than others. There definitely are differences.

And another thing... what needs to be established first is what which reviewers describes as what kind of thing.
Dynamics in electrical, digital, studio and perception are not describing the same effects.
That needs to be set in stone and agreed upon IF this is an attempt to quantify some descriptors.

It is a similar effect as people claiming high gain settings sound more dynamic than lower gain.

So.. its a fun experiment but one would have to measure SPL for this to mean anything.
Once you have the idea something sounds a certain way your brain will surely help you.

This is the problem between any subjective finding and measurements.

I do get various headphones to measure and often when listening to them the first impression often is not the same as a later impression or after time getting used to it. Opinion later on can still vary when having listened to another one for a while.

Subjective opinions (slam, punch, and whatever other nice description) are dependent on many factors. That's the reason why there is no (or little) hard correlation to measurements.

This basically also is the whole discussion between Amir and Resolve. I get both their standpoints. Both make sense. I agree with both.
Amir is of the standpoint (just like Rtings) that one should only look to measurements to evaluate. Resolve does both but relies more on impressions in his review. Amir to measurement facts.

I am in between. I measure and listen but rely more on measurements. The reason for that is the same as Amir. You can't trust impressions. Regardless how good one is.

For instance, Tyll made videos, so do many others like Z etc. I also heard quite a few they review and the few reviews I have seen of headphones I know or tested are not the same. Not even between reviewers. So take impressions for what they are.. personal findings. You may agree with some, you may not.

Facts are 'facts' also isn't fully true either. Measurements made on the same rigs often correlate well (when done correctly) but between setups they don't. Let alone target curves and interpretations as well as seal influences and positioning on the head.
Also these 'facts' contain errors and not everything that may require specific tests are done (correctly) either and maybe some test protocols (signal types) for electrical equipment is less suited for acoustical and maybe some tests still have to invented or improved.

In short: correlating measurements to perception often is impossible to do due to the brain/ears/gears/conditions/individuals/tastes/recordings used.

Great analysis, thanks for this.

It seems there are two things that severely limit the testing of headphones: the complexities around HRTF, which limit the accuracy of objective results, and the fallibility of human perception, which limits the accuracy of subjective results. Taken together we’re unlikely to ever have a level of accuracy in headphone testing that compares to speaker and electronics testing.

 

[jae]

I'd say a more "accurate" or "controlled" way of doing this is not with music but would be with more simple series of tones you are in full control of, that are modulated and manipulated in various simple ways. You'd probably have to run trials with many different bands and combinations of bands. If you can't hear or discern "macrodynamics" between two headphones like this then we can assume there's probably no way it will be obvious in actual music that is heavily masked, and that you are attributing this sensation to something else.

The problem with doing this experiment is that there are way too many practical limitations and things you have to control for. You would have to accurately level match each headphone with a multimeter. If you wanted to control for a variable such as FR you would have to accurately FR match but that introduces all kinds of unknown error or anomalies, distortion etc. You should also ideally have to account for your own in-ear measurements as well, or account or major design differences between models. Human auditory memory is also extremely short/non-existent and the only way around this is playing each stimulus one after another in quick succession with minimal delay, which is not exactly possible or practical to do with headphones (you would have to take one off and put another one on over and over and accurately seat it each time with an identical fit and seal). Plus this isn't even accounting for any inherent error and biases of a sighted experiment that does not have any other controls.

It simply makes the most sense to trust the measurements if they are done well, and weigh them heavily in the decision making process. Find whatever headphone you like or you have and see how it measures in various aspects and compare it to other headphones you may like that vary in other ways. Find out what is similar between the measurements and what is different, and use the deductive process to find what you like in a headphone, and use this info to make audition or purchasing decisions, or even to decide which headphones you prefer for a specific use case like gaming, listening to certain genres, critical or relaxed listening, etc.

 

[someguyontheinternet]

Thank you for your comments so far.
I think I should elaborate on the approach I want to take with this as well as the potential challenges I have identified (which have also been commented on).

The most prominent difficulty I see in problems of this class is the lack of structured information. Only when enough data exists can reasonable conjectures be made. While the existing measurement approaches for headphones should cover most (if not all) characteristics a headphone can exhibit, I think it is important to attempt verification for the completeness of our data.
Characteristics like soundstage are among those that can be speculated to show indications in measurements, but we are not sure if it really is the case and which measurements exactly influence those characteristics in what way. For all we know there might also be different ways in which certain characteristics can be induced which further complicates the analysis.
To use the soundstage example specifically: Amir has brought up the conjecture that messiness in group delay at mid-frequencies may be one way to induce this characteristic. However the DCA Stealth does not exhibit the same messiness in group delay, but still appears to show this characteristic. We can conlude from this that either the group delay has no impact on this characteristic whatsoever or that there may be multiple ways in which this characteristic can be achieved.
Crucial to these conjectures however is the existence of useful data and useful data can be gathered if experimentation to find a consistently reproducible test has been done. That is why it is subjectively sensible to me personally to attempt this even if it should turn out to be fruitless.

For these kinds of "hidden" or undiscovered correlations I personally found it helpful to start by assessing unstructured information first. From the unstructured information common denominators may provide the data necessary to carry out more controlled experiments.
In this case I want to start with actual music, because it offers by far the biggest pool of information. From there I want to identify common denominators and start picking apart what frequencies, legths, delays, etc exactly are necessary to evaluate the characteristic (if it exists). Since differences can exist in the test setup I would have to progressively identify and eliminate possible variables. Every experiment has to start at some point though even if a perfect setup is not feasible given a certain time frame and limited resources.

The problems of tonality and volume matching have been correctly pointed out already. I am also pondering how exact I need to make these given my goal. The most exact would of course be ideal, but I think doing a rough approximation and a more exact calibration may yield additional data on the scope of this characteristic. My guess is that if it shows at both rough approximations and exact calibration, that may indicate a characteristic that is inherent to a quality independant of tonality.

In the end I guess I'm seeing a problem and no point at which to start the analysis. My experiences from doing my degree and analysing problems at work have resulted in the tendency to start by making things more tangible, even if it is only by a little. Every little step will ultimately lead to better data which in turn leads to better conjectures which in turn will result in better understanding and experimentation.
It all has to start somewhere though.

 

[Jimbob54]

I think you need a readily understandable and translatable definition of "macrodynamics". It's not a concept I can identify with. Once we get past bass, mid, treble, imaging and soundstage im a bit lost tbh. Let's not go down the audio plankton route!

 

[dc655321]

I think you need a readily understandable and translatable definition of "macrodynamics". It's not a concept I can identify with. Once we get past bass, mid, treble, imaging and soundstage im a bit lost tbh. Let's not go down the audio plankton route!

Amen.
Start by defining "macrodynamics". With physics.

 

[maverickronin]

I wonder if this is supposed to be the same thing as bass slam, because it doesn't seem to be dynamic compression.

I've always perceived slam as the amount of vibration from the headphones which is coupled through to your head which would be a function of the mass of the diaphragm and the pads' and headband's influence on its transfer.

 

[Doodski]

I think you need a readily understandable and translatable definition of "macrodynamics". It's not a concept I can identify with. Once we get past bass, mid, treble, imaging and soundstage im a bit lost tbh. Let's not go down the audio plankton route!

I googled the term(s) and found this stuff here and here. It appears to be more of a musical reference to the musicians playing louder or quieter.

 

[Jimbob54]

I googled the term(s) and found this stuff here and here. It appears to be more of a musical reference to the musicians playing louder or quieter.

I can understand how you could start to relate microdynamics as defined there to headphone response, how it handles transients compared to another rig. Macrodynamics as defined there is purely a performance /recording concept then.

 

[Longshan]

I googled the term(s) and found this stuff here and here. It appears to be more of a musical reference to the musicians playing louder or quieter.

Must be another example of folks making up terms then acting like these are common ideas.