[YTCrazyTieGuy]

Hello,
 
I appologize if there is already a thread on this, i didn't have much time.
 
Can i directly compare the fr measurements of full size headphones and iems on innerfidellity and headroom?
 
ty
 
ytcrazytieguy

 

[limpidglitch]

No.
 
In fact Tyll touched upon the issue in a recent article. Even comparisons between supra-/circum-aural and open/closed designs should not be done lightly.

 

[YTCrazyTieGuy]

Thank you very much! this exactly answers my question, though is a bit disappointing

 

[bigshot]

For the life of me, I don't know why people make frequency response so complicated. Corrections correcting for corrections... Flat response isn't flat... Graphs that don't reflect what humans hear... All someone needs to do is find a person with excellent hearing and an average shaped head, have them balance a tone sweep with an equalizer, and apply a Fletcher Munson correction to the EQ curve. That won't split the atom when it comes to accuracy, but at least it will result in a graph that actually means something.

 

[YTCrazyTieGuy]

Now that I think about it the shape/type of the headphone shouldn't matter, what should matters is the frequency response that reaches the eardrum, it shouldn't matter how it gets there. If the architecture of a headphone affects the ear resonances (for example an iem bypassing the outer ear resonances), it should compensate for it with it's sound.
 
I got this message from headroom in response to a question a few days ago:
 
"The frequency curve compensation is the same for in-ears as well as full size headphones. Yes, you can compare them side by side. However in a real world application, there are things like noise isolation and soundstage that affect your experience that measurements can't represent properly. The measurements are a great tool as a guideline, but they don't represent 100% exactly what a headphone sounds like. Just keep this in mind and please let me know if you have any other questions."
 
Here Tyll explains his measuring procedure - the compensation he uses is an HRTF, and is independent on the headphone:
 
http://www.innerfidelity.com/content/headphone-measurement-proceedures-frequency-response
 
Still, it's quite hard for me to find a headphone and an iem that measure similarly and are considered to find the same, just as the fidelio guy pointed out (although i didn't look very hard). maybe someone else can help with this?
 
@bigshot we make it complicated because its fun and makes us feel scientific ^^ though hopefully it's simpler that we make it to be.

 

[bigshot]

I guess I am more focused on listening to music than science. I just want stuff that sounds good to my ears. Using science is a good way to achieve that if you keep your eyes on the prize.

 

[mikeaj]

I don't know if I'd trust HeadRoom over design engineers at a manufacturer with respect to compensation curves for different headphone types.
 
IIRC it was Tyll who did most of their database of measurements for HeadRoom; when he left to do InnerFidelity, he does them now on a contract basis. Again, I think.
 
As always, we all know listening to the stuff yourself is better, but sometimes that's not a possibility. As for others' impressions of headphones, sometimes that translates well, other times not so much for various reasons.

 

[castleofargh]

I always felt that I needed more bass on IEMs than on headphones. a flat FR on fullsize headphone is almost ok for me. a flat line on IEM would usually sound like not enough bass or at least sub bass to me.
as they measure with dummy heads and mics inside the ears, it shouldn't make a difference, but to me it does. I really can't say why, I once though that maybe the pressure from inserting the IEM was stressing the eardrum and changing our own frequency response. or maybe the problem was at the measurement, could the microphone be pressurized and have different response than what it's  usually calibrated for? anyway that's just a loony theory of mine I know nothing about dummy heads or if microphones in the head are even under any kind of pressure or how long they wait after insertion to make the measurements. (you know nothing jon snow!)

 

[YTCrazyTieGuy]

"I know some things"
 
it's too bad you can't do a blind test comparing in ears and full sizes in the end though a personal opinion is worth just as much as a graph sometimes imo, ill keep it in mind.
 
@mikeaj at first I didn't trust headroom over the fidelio guys but I tend to trust my own logic quite a bit and my logic tells me the compensation should be the same. Plus the overall impression i got from reading various things is similar, except for this one fidelio thing.
 
Still, It would be nice to see an iem and a full size that have a similar graph and subjectively sound similar, for confirmation.

 

[limpidglitch]

It would have been nice if Tyll could elucidate a bit on what he's thinking.
I agree that the transfer function should be the same, but I also agree on that there are some discrepancies between the measurements and my own experience. I don't know what's going on.
 
How is it we call him forth; Tyll Tyll Tyll, then click our heels thrice?

 

[bigshot]

He serves a different audience, I'm afraid

 

[Tyll Hertsens]

Don't know what makes you think that, Bigshot.
 
 
Glitch, I'm afraid it's quite complicated and not very well studied yet. Both Sean Olive at Harman and Rowan Williams at Philips have told me they believe there are differences in target response at the ear drum between headphone types, but they don't know what it is or exactly why it exists. And if they're perplexed and curious, I'm certainly in no position to pose an explanation. 
 
It's a mystery at this point.

 

[limpidglitch]

He serves a different audience, I'm afraid

 
It's a larger audience, for sure, and therefore also different. But it's also a lot the same.

Seems like clicking my heels did the trick.
Thanks, for the input, Tyll. When the big brains are so thoroughly confounded, it must be a great mystery indeed.
Do you know of any ongoing research, some hints to what it might be, or are everyone keeping their cards close to their chest?

I wonder if our brain is subconsciously registering the change in acoustic environment, and then applying some sort of automatic compensation EQ. Our brain already does most of it's work without us being the slightest aware of it, so it wouldn't surprise me if something like this was going on. But I'm not a cognitive scientist, not by a parsec.

 

[spaark]

  All someone needs to do is find a person with excellent hearing and an average shaped head, have them balance a tone sweep with an equalizer, and apply a Fletcher Munson correction to the EQ curve. That won't split the atom when it comes to accuracy, but at least it will result in a graph that actually means something.

What you're talking about is independent of the listening environment. This sort of weighting won't compensate for the acoustic differences between speakers, headphones and so on. In fact, I don't think it has any place in measuring the frequency response of the playback device, as perceptual loudness should be factored in the mastering process.

 

[bigshot]

You have to apply the inverse Fletcher Munson, because if you do a balanced tone sweep by ear to completely even all the way across, your ears will have automatically corrected for Fletcher Munson. If you subtract the Fletcher Munson by adding volume in the places that are affected by FM you are back to true audibly flat.