• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

IEMs equalized to Harman IE target sound total different from AKG K371 ,or any other over the ears Headphones EQ to Harman OE target.

oluvsgadgets

Member
Reviewer
Joined
Feb 27, 2021
Messages
29
Likes
99
you are all aware that an IEM measurement with a standard coupler resonance of 8khz will not represent the sound you perceve in any way, depending on your ear canal length and the resonance you are getting?
this is something which is not talked about in any paper, but actually all these measurements are just snapshots of how the coupler will measure at the given insertion depth etc which may but probably won't even be close to how you will perceive the final sound. average resonance is about 6600khz while all measurements shown are at 8000khz.

here an example of the MH1 in blue how it would be measured "correctly", while green how it will be perceived by most:
sony-mh1.png
 
Last edited:

someguyontheinternet

Active Member
Joined
Apr 16, 2021
Messages
194
Likes
335
Location
Germany
Of course a model that is created using statistical evaluation can deviate from any individual and it is part of papers. Welti (if I remember correctly) measured multiple people's in-ear responses for over-ear headphones for a paper, because a standard model had deviations from real human ear responses. As a result a new model was created.
If the issue is known for over-ear measurements, it seems unlikely to me that researchers wouldn't know about this issue for in-ear measurements.

Amir even includes a paragraph on the unreliability for certain frequency areas in headphone reviews:
AMIR_MEASUREMENT_NOTE.PNG
 

oluvsgadgets

Member
Reviewer
Joined
Feb 27, 2021
Messages
29
Likes
99
This sounds to me like: “sorry officer my Tachymeter isn’t as precise in the 80-120km/h range thus I was not even aware I drove more than 100 in an urban area…”

If you cannot measure it precisely or if the measured result does not represent the perceived result, these measurements are worthless!
 

someguyontheinternet

Active Member
Joined
Apr 16, 2021
Messages
194
Likes
335
Location
Germany
That is also elaborated on in the paragraph of amir:
As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests.

If the instrumentation is not sufficiently accurate, it has to be consolidated with other means.
 

MayaTlab

Addicted to Fun and Learning
Joined
Aug 15, 2020
Messages
956
Likes
1,593
Welti (if I remember correctly) measured multiple people's in-ear responses for over-ear headphones for a paper, because a standard model had deviations from real human ear responses. As a result a new model was created.

The leakage article mainly focused on response below 1kHz. The new custom pinnae that were developed followed more closely the on-head measurements as an overall statistical trend, and considerably improved the accuracy of the measurements for some individual headphones (mainly on-ears or small over-ears), but the deviation didn't improve for some other individual headphones (K550, it actually got worse for them) and quite a few of them still didn't match superbly well the on-head response.

What this paper makes a fairly strong case for, IMO, is the use of fully open dynamic headphones as a way to test target curves preferences, as they were found to have the least variance below 1kHz between listeners and test fixtures (or ANC headphones with a robust feedback mechanism, but I believe that these may exhibit variance issues above 1kHz).

Above 1kHz no data was provided and in situ measurements are a lot harder to perform anyway. We have no knowledge of whether or not the newer pinnae are more accurate to on-head behaviour.

If the issue is known for over-ear measurements, it seems unlikely to me that researchers wouldn't know about this issue for in-ear measurements.

The article on the validation of the in-ear virtual test metholdogy at no point did insert the actual IEMs into the listeners' ears, unlike the over-ears article.

The methodology, which as I understand it, compared recordings of the "real" IEMs on an ear simulator vs equalised signals (the "virtual" IEMs), both played back through a replicator IEM with a MEMS mic in the front volume to equalise the replicator IEM's bass response to be constant across listeners, by design eliminated all questions of HPTF variation / issues.

To the point where I personally see it rather as a test of the influence of non-linear factors on preferences (and yet another article seemingly demonstrating that FR largely is the dominant factor), much less as evidence that the virtual IEM methodology is an accurate way to test preferences for individual, real IEMs (which actual on-head behaviour in that research's context isn't known).
 

sfdoddsy

Active Member
Joined
Jun 6, 2019
Messages
293
Likes
438
The problem is that you don't know either the actual response for the K371 for your ears, or the actual response for your ears of the IEMs.

I went through a stage of trying to EQ my speakers and headphones to match but quickly gave up.

Whilst headphones and IEMs are closer, they are still inherently different.

I suspect the best you can hope for is that a headphone and IEM which track your preferred curve will both sound great. Different in some ways, but still great.
 

AD1747

New Member
Joined
May 24, 2022
Messages
1
Likes
0
you are all aware that an IEM measurement with a standard coupler resonance of 8khz will not represent the sound you perceve in any way, depending on your ear canal length and the resonance you are getting?
this is something which is not talked about in any paper, but actually all these measurements are just snapshots of how the coupler will measure at the given insertion depth etc which may but probably won't even be close to how you will perceive the final sound. average resonance is about 6600khz while all measurements shown are at 8000khz.

here an example of the MH1 in blue how it would be measured "correctly", while green how it will be perceived by most:
View attachment 174055
Sorry to dig up an old thread, I am new to this forum and found this very interesting.

So for IEMs there is distinct difference between actual perceived sound and correctly measured curve pass 1kHz. If green is the ideal sound I want to hear from my IEMs, I will need to tune them to fit the blue target curve.

Question is how do I compensate for the difference between a standard coupler and my ears? What is the simplest way to define a compensation curve for any individual? Perhaps one curve for each ear?

Thanks!
 

oluvsgadgets

Member
Reviewer
Joined
Feb 27, 2021
Messages
29
Likes
99
You need to know your ear canal resonance occurring with the affected unit and trying to recreate that response with your measuring device. But there may be offsets in the response depending on the coupler thus the measured response still won’t correspond to your perceived response. I often hear peaks in the response which do not show up in the measurement regardless how deep or shallow I insert it, most couplers are not even designed to be able to measure at resonances of the average human ear. 8khz is way too high. I have mine usually around 6khz but a standard coupler won’t allow me to measure that low.
It’s all very wishy washy, and the most stupid fashion is trying to equalize the final response towards some weird target curve which is heavily smoothened. And the best is if everyone is raving about the sound because it follows strictly some target curve while still everyone is getting completely different responses.
 
Top Bottom