[castleofargh]

So just as a sanity check, I did some manual tone sweeps with my most bass-capable headphones and a few others for contrast.
I am definitely able to hear/feel tones down to about 8-9hz (and up to about 16.5kHz)

Interestingly, most of my headphones and even IEMs had severe roll-off or simply cut off altogether around 18-20hz.
Two of my headphones in particular with stunning bass capabilities could produce pulsating sensations or tones 'audibly' down to 10hz, but below that needed an increase in volume to compensate for natural transducer roll-off.
I could 'feel' these pulsations down to 4-5 hz quite vividly, but below that it's difficult to know if they are tonal vibrations or just the transducer crapping out at the lowest extremes, so for arguments sake we can ignore everything below 5hz.

So I am starting to strongly suspect that either the 'accepted standard' of human hearing starting at 20hz is somewhat grossly inaccurate and needs updating, or I am an outlier of the norm and have highly sensitive bass hearing.
... or perhaps some of these so-called 'hearing tests' are done with inappropriate transducers that are simply not up to the job.

Interesting either way it leans, there's still so much we don't know about audio and hearing. As a science, it's in it's infancy in comparison to others.

a few things to define before attempting to conclude anything:
- what do we define as hearing? everybody can feel his lungs shaking from some strong sub frequency rumble, or totally perceive a earthquake moving the ground at the frequency of a few hertz. but does that count as hearing? in my opinion it doesn't. I'm not trying to reject the fact that we experience something and that it's related to sound or sub frequencies, I'm just saying that to me hearing has to do with ears. it's a way of clearly defining what I'm talking about, more than an argument about reality.

- are your "tests" ensuring that when you're hearing or feeling something, it's effectively the frequency you're sending as a tone and not a side effect of that signal?
mega warning 3000 /!\ I have neither the right equipment nor the proper knowledge required to know that I've measured this properly!!!!!!!! but I couldn't find a clear example on the web with an IEM so I made one ^_^.

here we're looking at a tone of 18.3Hz being played in my er4sr(not exactly the bass heavy IEM^_^) so that the output would be a little below 95dB SPL at that frequency. first thing I have to say, is that this is louder than I ever listen to music. at this setting the 3kHz area would be like 20dB higher, so it's loud but still a value we consider when thinking about driving our gears and looking for the right amplifier.
the numbers show the harmonics created by the IEM when playing that 18.3Hz tone that loud. so 2 is 18.3X2=36.6Hz 3 is at 18.3*3=54.9Hz etc.
you can read in the little window that the 2nd harmonic reaches 1.69% and 3rd 2.29%. which is pretty high for IEMs because the tone is loud. at more reasonable levels that I usually use to do my frequency response and THD graphs I'd be around 1% THD for the 18Hz tone on that IEM. but for some full size headphones or speakers/subs, being well above 1% THD at such frequency is absolutely normal. I'm just saying this to try and put things into perceptive for those not familiar with harmonic distortions. as for the cause, well it's simply that the driver for various reasons will not move following exactly the amplitude variation of the sine wave(small differences in amplitude and/or phase due to; air resistance, the driver trying to retract to its resting position, previous air waves still bouncing around in the area, etc), and that will effectively mean the creation of new frequencies.(which is more obvious when we know that any signal can be decomposed as sums of sines. then any shape that's not a pure sine is going to be that sine wave plus some other sines, math says so).

so back to our numbers and what they actually mean. the third harmonic is in this particular case the loudest frequency after our original test tone of 18.3Hz, and 2.29% distortion is a weirdo way of saying that it is 33dB quieter than the original tone. so here let's round up the all thing and say that I'm getting a 60dB SPL 54.9Hz sound(among others, but that one is loud and something everybody in a reasonably quiet room could notice). it comes out of my IEM despite how I only sent a 18.3Hz tone into it. and by now I hope it's clear that hearing something doesn't necessarily mean hearing the initial frequency, as several others may also reach audible levels.

this is only one of the possible explanations I mentioned last time, but this post is already way too long so I'll stop there ^_^.

 

[GREQ]

1. The increased volume would blow your head off

This is simply not true.
Since you won't take my word for it...
Here are my measurements of my HD650 (blue) and HE-500 (purple), and my two other VERY bass-capable headphones (orange and red).

At 3-4hz, you can notice that the amplitude is still within hearing for the two bassy headphones.
HE-500 and HD650 both cliff-dive at 10hz.

Not devils advocate - just putting a measure of realism into the conversation. What you’re doing is listening to single tones, and you increase the volume until you hear it. But if you were listening to actual music -
Plus I thought we’d already established that practically no musical instrument goes that low anyway - so what’s the point? Even a bass guitar sits at 40Hz. A pipe organ could go down to 10Hz, but unless you are exclusively listening to baroque playing dubstep ........ I think you get the point

This is totally irrelevant, since established musical notes represented by tones in Hz is not the whole recording or sound of an instrument when you consider all the percussive sounds created when playing instruments.
Saying "what's the point" is just ignorant. If the transducer isn't capable of producing what should be 'felt' because it's there in the recording is basically admitting you don't care about the whole recording.

 

[Brooko]

Disengaging - little point in continuing this. Enjoy your music

Oh and as far as graphs go - unless you're using an isolation chamber, and proper equipment, you won't get reliable graphs. So again (to your original question) - very little point in measuring something which will be wildly inaccurate.

 

[Fuzzy789]

I'm going to be the dissenting voice here.
What do you mean by "full and exciting?" When I think of a "full" sound, I usually am thinking of bass response; and when I think "exciting" I think both bass and treble. Maybe you mean something different by those terms, but an IEM, in my book, can do those things just as well as any on- or over-ear. There are only two reasons that an IEM wouldn't have the same bass response as a full-sized headphone: 1) it's just not within its signature; or 2) you're unable to attain a proper seal. Driver size is only part of the equation.
To my ear, the only way that a full-sized headphone really "beats" an IEM is in soundstage, and even that, for me, is only a narrow margin. I'm probably not as much of a soundstage hound as a lot of Head-Fiers, as I've never really desired more than my HD 650 of DT 1990 could provide-- both of which could pretty generously be described as "intimate." From my experience, the UM Pro 50's soundstage is not that much narrower (if at all) than either of those open cans, but the HD 650 and DT 1990 are more three-dimensional and realistic.

And for me, the convenience factor of an IEM is HUGE and should not be discounted. My open headphones sound amazing at home, but would be useless if I took them outside. Even my PM-3, which were marketed as being portable, are not nearly as real world portable as my IEMs.

Yeah, an IEM isn't going to rattle your skull the same way an over-ear will. But then, an over ear can't hit you in the chest like a subwoofer can, and a subwoofer won't shake the world to pieces like a passing train. This is kind of like saying apples are better than oranges because you can't make an apple pie with an orange.

I'm not trying to argue that you or others shouldn't prefer full-sized headphones to IEMs, and maybe you're just hearing things differently from me, but I just can't see how an across the board statement that full-sized are better than IEMs is justifiable.

The only reason i would accept if they can't get a seal with IEM's, Because with something like a ER4 a proper fit and seal is everything. I honestly like my ER4SR more than my SRH1540,

 

[GREQ]

Disengaging - little point in continuing this. Enjoy your music

Oh and as far as graphs go - unless you're using an isolation chamber, and proper equipment, you won't get reliable graphs. So again (to your original question) - very little point in measuring something which will be wildly inaccurate.

A moot point.
Bass measurements are extremely accurate compared to treble measurements which even on professionally isolated high-end rigs are said to be 'wildy inaccurate'.

 

[castleofargh]

A moot point.
Bass measurements are extremely accurate compared to treble measurements which even on professionally isolated high-end rigs are said to be 'wildy inaccurate'.

strictly compared to treble(basically anything above 10kHz), yes, bass can be many times more accurate.
now as to being actually accurate in general... not so much. we could start by how you have to make sure you have the proper settings(stuff as trivial as creating a window that can encompass a full period of the low freq. not hard, but not something the average curious amateur is going to know about). then we can look at how easy it is to affect the amplitude at those frequencies with the slightest change in seal. there we have something pretty similar to upper trebles, where the manipulation directly impacts the results. with headphones, depending on the pads you'll have great differences on different placement, and yet some more if you let the pads settle for a while or not. on IEMs the tip used, the type of coupler that may or may not hold the tip correctly, how the guy making the measurement might have bothered adding putty of whatever to keep the IEM at the reference plane he has created for his rig or create his own seal over the tip, etc. we can already see that in the sub 100Hz area, and the lower we go the more dramatic the impact of any small change.
then you can ask yourself why microphones aren't all certified from 0Hz to XkHz even when they come with their own individual calibration file.
and all that doesn't even bother with the matter of actually hearing those freqs which you seem to have decided you could because of a dubious way to test that.


as I said before, getting a graph is easy, getting meaningful stuff on it is another story. so if you wonder if there is something almost full scale at 10Hz or nothing to find until maybe -60dB, then I'd suggest that any mic can tell you that much, kind of the same way most mics can tell if there is basically something or "nothing" at 18kHz. but looking at any graph below 100Hz already tells you just as much. if you think you need more specific information, the answer I would give is that at least with my cheapo rigs, I cannot ensure the results to be correct. I can't even bet on an order of magnitude for how wrong I might get. that's how unsure I am.
all in all the one point where I can wholeheartedly agree with you is that if we bother showing BS stuff in the upper treble up to 20kHz, it wouldn't change much to also show BS stuff from 0 to 20Hz. but in my view that would be an argument in favor of removing content above 10kHz(or let's say maybe 13kHz for some gears). not an argument in favor of adding more fake data on every graphs.

 

[SilentNote]

Headstage aside, I have yet to hear an over ear headphone that sound significantly better than IEMs at similar price points.

In fact most headphones I have heard at the same price bracket sound less detailed and more grainy than IEMs.