How to measure IEMs cheap for use with AutoEQ?

[Gershy13]

Hey all,

I was wondering if anyone could give me some tips on measuring IEMs/earbuds for use with AutoEQ.app

I have a dayton imm-6, and i saw that its quite common to use that and a tube to get measurements for not too much money.
I don't need the measurement to be perfect, just good enough where i can save a file and upload it to AutoEQ for personal use.

For instance, i have a pair of Redmi AirDots 3 Pro, however they do not sound the best to me, so i would like to EQ them to AutoEQ target (or harman).
What is the best way to go about doing this? I assume i would need some sort of tubing to go between the imm6 and the earphone? Is there a certain type/length or anything it needs to be?

What is the workflow for something like this? Again, i don't need the measurement to be perfect, just a rough curve that would allow me to EQ earphones that aren't on the autoEQ database.

Thanks
Gershy13

 

[staticV3]

For instance, i have a pair of Redmi AirDots 3 Pro, however they do not sound the best to me, so i would like to EQ them to AutoEQ target (or harman).
What is the best way to go about doing this?

Forget about the imm-6, as it is outright incompatible with the AutoEQ target, the Harman target, or any other worthwhile frequency response target.

If you want to make use of established targets, then you need an IEC60318-4 compliant coupler, frequently called 711 coupler.

They cost a pretty penny from proper manufacturers like GRAS or B&K, however, you can purchase Chinese clones of these couplers on AliExpress for $70-110:
https://www.aliexpress.com/item/2255800731956095.html
https://www.aliexpress.com/item/2255800603481769.html
https://www.aliexpress.com/item/3256801383861929.html
https://www.aliexpress.com/item/2255800038204879.html
https://www.aliexpress.com/item/3256801384150335.html
https://www.aliexpress.com/item/2255800318673459.html

Quality control is naturally nowhere near as good as from GRAS etc, but they can still have reasonable accuracy.
For example, here's how my 711 clone coupler compares to a genuine GRAS RA0045:

The graph shows the frequency response error of various IEMs, compensated to the RA0045 measurements.
The same IEM units and ear tips were used on both couplers and the insertion depth was matched as best as possible.

I would be comfortable using the 711 clone coupler to EQ IEMs to Harman, up to about 8kHz.

 

[Gershy13]

Forget about the imm-6, as it is outright incompatible with the AutoEQ target, the Harman target, or any other worthwhile frequency response target.

If you want to make use of established targets, then you need an IEC60318-4 compliant coupler, frequently called 711 coupler.

They cost a pretty penny from proper manufacturers like GRAS or B&K, however, you can purchase Chinese clones of these couplers on AliExpress for $70-110:
https://www.aliexpress.com/item/2255800731956095.html
https://www.aliexpress.com/item/2255800603481769.html
https://www.aliexpress.com/item/3256801383861929.html
https://www.aliexpress.com/item/2255800038204879.html
https://www.aliexpress.com/item/3256801384150335.html
https://www.aliexpress.com/item/2255800318673459.html

Quality control is naturally nowhere near as good as from GRAS etc, but they can still have reasonable accuracy.
For example, here's how my 711 clone coupler compares to a genuine GRAS RA0045:
View attachment 323728
The graph shows the frequency response error of various IEMs, compensated to the RA0045 measurements.
The same IEM units and ear tips were used on both couplers and the insertion depth was matched as best as possible.

I would be comfortable using the 711 clone coupler to EQ IEMs to Harman, up to about 8kHz.

Thanks! I guess it's not really worth it then. My main use was to make my cheap ANC earphones sound a bit better quickly, I guess the best i can do without spending too much money is just doing it by ear.

Unless i specifically needed to measure multiple earphones, it would probably just be a better idea to put the money i would spend on a coupler towards a new pair of earbuds with ANC that are already measured and sound good. Something like the galaxy buds or sony wf series

 

[Jimbob54]

Thanks! I guess it's not really worth it then. My main use was to make my cheap ANC earphones sound a bit better quickly, I guess the best i can do without spending too much money is just doing it by ear.

Unless i specifically needed to measure multiple earphones, it would probably just be a better idea to put the money i would spend on a coupler towards a new pair of earbuds with ANC that are already measured and sound good. Something like the galaxy buds or sony wf series

Google squiglink and see if any of the review sites has measured your hp. Not all of them make it into the autoeq db

 

[Gershy13]

Google squiglink and see if any of the review sites has measured your hp. Not all of them make it into the autoeq db

Unfortunately it's not on there.

 

[avi0707]

Hello to where to dowload many targets for iem to add to REW.

 

[staticV3]

Hello to where to dowload many targets for iem to add to REW.

You can find a bunch of IEM target curves here: https://github.com/jaakkopasanen/AutoEq/tree/master/targets

Please note that these are specific to the measurement rig being used.
I.e. Harman targets only work for IEC60318-4 measurements, II.3 targets only work for II.3 measurements, etc.

For regular IEC60318-4 "711" measurements, including those from Amir, also give the target curve attached below a try. To my ears, it sounds a lot better than Harman.

Lastly, if you want to experiment with EQ and different target curves, check out https://autoeq.app/.

It has everything you need for the job, even a built-in audio player where you can A/B different EQ settings.

 

[avi0707]

Ok I just bought this. Also was able to use soundcard with measuring mic and smart v9 blue pink green iem moondrop starfield. Just looking for a tutorial. Is it i measure then add the curve and match it? Easy enough thank you kindly.

I tested with capture on smaart export to rew added curve then export rephase out to eqapo. Sounds nice. Now looking for a dac or dap player that can use convolution files. Only thing I see is hiby r5 r6. Was looking for something cheap or a dongle with iPhone any suggestions please. Have zero knowledge on daps or dacs. I also have AirPods Pro 2 was wondering how to measure those? Thank you again.

 

[USER]

I received the recommended 711 clone this morning and have been playing around with it to good results. It is my hope that I can create a conversion EQ to get them surprisingly close to Amir's measurements, which are taken on a GRAS set-up. I have had good luck with this with the better measurements on squig.link and have been able to get consistent and dependable results. They are scattered on this site, though I will be posting about it in more detail. This seems to work because many people have measured the two Salnotes Zeros and the two Truthear Zeros. I have 3 Salnotes Zeros, 2 Salntoes Zero: 2s, and a Truthear Crinacle Zero awaiting proper measurement in order to calibrate and create a conversion EQ.

Here is a quick comparison between my initial results and Amir's results

Note that I have yet to receive the calibration file for the coupler so these are draft measurements. Still, most of the differences are already consistent with what I have seen and corrected, so I believe I am off to a good start. Can't wait to receive the calibration file so I can get going.

I think fear of IEM inconsistency is overblown when it comes to decent IEMs. The thing is that you really have to shoot for a 8kHz resonance and I feel some people are too impatient to try and try again. Certainly soft tips make this more difficult, but one can get there. Here is a right and left channel comparison of a second Salnotes Zero with a covered vent and "bass boosting" tips. Great results if I say so myself.

For the purposes of tip evaluation, the coupler is already insightful. I have a collection of mesh filters that I hope to try out with brighter IEMs to see if I can get them to my liking without the use of EQ.

So much for those "bass boosting" tips.

This coupler is already starting to pay for itself. I found a major issue with a $2 pair of IEMs I purchased for practice. Now this is inconsistency.

I am hoping to be able to perform distortion measurements once my XLR connector arrives and I can use my E1DA Cosmos set-up.

If anyone has any questions about setting up something similar let me know. But, again, I'll be posting about it in the near future.

 

[markanini]

I received the recommended 711 clone this morning and have been playing around with it to good results. It is my hope that I can create a conversion EQ to get them surprisingly close to Amir's measurements, which are taken on a GRAS set-up. I have had good luck with this with the better measurements on squig.link and have been able to get consistent and dependable results. They are scattered on this site, though I will be posting about it in more detail. This seems to work because many people have measured the two Salnotes Zeros and the two Truthear Zeros. I have 3 Salnotes Zeros, 2 Salntoes Zero: 2s, and a Truthear Crinacle Zero awaiting proper measurement in order to calibrate and create a conversion EQ.

Here is a quick comparison between my initial results and Amir's results
View attachment 364007

Note that I have yet to receive the calibration file for the coupler so these are draft measurements. Still, most of the differences are already consistent with what I have seen and corrected, so I believe I am off to a good start. Can't wait to receive the calibration file so I can get going.

I think fear of IEM inconsistency is overblown when it comes to decent IEMs. The thing is that you really have to shoot for a 8kHz resonance and I feel some people are too impatient to try and try again. Certainly soft tips make this more difficult, but one can get there. Here is a right and left channel comparison of a second Salnotes Zero with a covered vent and "bass boosting" tips. Great results if I say so myself.
View attachment 364008

For the purposes of tip evaluation, the coupler is already insightful. I have a collection of mesh filters that I hope to try out with brighter IEMs to see if I can get them to my liking without the use of EQ.

View attachment 364012View attachment 364013View attachment 364010

So much for those "bass boosting" tips.

This coupler is already starting to pay for itself. I found a major issue with a $2 pair of IEMs I purchased for practice. Now this is inconsistency.
View attachment 364014

View attachment 364015

I am hoping to be able to perform distortion measurements once my XLR connector arrives and I can use my E1DA Cosmos set-up.

If anyone has any questions about setting up something similar let me know. But, again, I'll be posting about it in the near future.

There's more than one Gras device, Amirs has a pinna attachment and a RA0402 or equivalent coupler, different from what 711 clones target. You will be better off calibrating to measurements made on pinaless Gras RA0045.

Fresh From the Bench: G.R.A.S. Sound & Vibration RA040X Ear Simulator

Brent Butterworth reviews the new RA040X Ear Simulators from G.R.A.S. Sound & Vibration. Measuring headphone response at frequencies above-10 kHz has been an imprecise, non-standardized process. The new RA040X ear simulator represents part of an effort by G.R.A.S. Sound & Vibration to update...

audioxpress.com

 

[USER]

There's more than one Gras device, Amirs has a pinna attachment and a RA0402 or equivalent coupler, different from what 711 clones target. You will be better off calibrating to measurements made on pinaless Gras RA0045.

Fresh From the Bench: G.R.A.S. Sound & Vibration RA040X Ear Simulator

Brent Butterworth reviews the new RA040X Ear Simulators from G.R.A.S. Sound & Vibration. Measuring headphone response at frequencies above-10 kHz has been an imprecise, non-standardized process. The new RA040X ear simulator represents part of an effort by G.R.A.S. Sound & Vibration to update...

audioxpress.com

The results have been quite good so I am satisfied. It seems to work, as long as you aren't expecting miracles above 8kHz. That will never match, but I care more about the important frequencies so that's OK. (I also think a lot also depends on how one reads the resonances.) More, I want to compare my own measurements to Amir's, whom I trust over most reviewers. (I tend to avoid the IEM scene altogether as I find most reviewers unqualified to discuss measurements.) In the context of posting on ASR, this is a good thing as it avoids further confusion. No one here is claiming high precision anyways. But the big thing is that to calibrate one needs a lot of common measurements and ideally one to test the efficacy after completion of the conversion EQ. I'd also need to find a dependable, consistent measurer who makes files available for RA0045 to make it work.

 

[markanini]

The results have been quite good so I am satisfied. It seems to work, as long as you aren't expecting miracles above 8kHz. That will never match, but I care more about the important frequencies so that's OK. (I also think a lot also depends on how one reads the resonances.) More, I want to compare my own measurements to Amir's, whom I trust over most reviewers. (I tend to avoid the IEM scene altogether as I find most reviewers unqualified to discuss measurements.) In the context of posting on ASR, this is a good thing as it avoids further confusion. No one here is claiming high precision anyways. But the big thing is that to calibrate one needs a lot of common measurements and ideally one to test the efficacy after completion of the conversion EQ. I'd also need to find a dependable, consistent measurer who makes files available for RA0045 to make it work.

It's more than just +8kHz. https://www.audiosciencereview.com/forum/index.php?threads/7hz-sonus.53284/#post-1931530 https://www.audiosciencereview.com/...x-crinacle-zero-red.44846/page-7#post-1724352 If you go ahead and create a delta to Amirs measurements you might as well create a delta for a more compatible system, only if you want others to make use of your measurements. Oratory1990 and hypethesonics raw measurements are available inside AutoEQ. https://github.com/jaakkopasanen/AutoEq/tree/master/measurements

 

[USER]

It's more than just +8kHz. https://www.audiosciencereview.com/forum/index.php?threads/7hz-sonus.53284/#post-1931530 https://www.audiosciencereview.com/...x-crinacle-zero-red.44846/page-7#post-1724352 If you go ahead and create a delta to Amirs measurements you might as well create a delta for a more compatible system, only if you want others to make use of your measurements. Oratory1990 and hypethesonics raw measurements are available inside AutoEQ. https://github.com/jaakkopasanen/AutoEq/tree/master/measurements

Your concern is valid but I am not terribly concerned for a couple of reasons. Amir's measurements draw thousands and thousands of viewers who use them so there is plenty of use value--within reason and acknowledging that my results, even when corrected, are from a knock-off, third party coupler, lol! Let's not forget that last part! That said, If I find the resources to explore other systems I'm sure I'll look into it eventually. (Is Oratory1990 the best source of that data? The fact that I personally haven't liked his EQ results has prevented me from exploring his work further. But I'll return to it.) I also plan on comparing my results to those of the better squig.link measurerers. When that happens I'll have a better understanding of where I am starting from.

Also, I'd love to read the article that is the source of the graph as it is very vague as presented.

 

[USER]

There's more than one Gras device, Amirs has a pinna attachment and a RA0402 or equivalent coupler, different from what 711 clones target. You will be better off calibrating to measurements made on pinaless Gras RA0045.

Fresh From the Bench: G.R.A.S. Sound & Vibration RA040X Ear Simulator

Brent Butterworth reviews the new RA040X Ear Simulators from G.R.A.S. Sound & Vibration. Measuring headphone response at frequencies above-10 kHz has been an imprecise, non-standardized process. The new RA040X ear simulator represents part of an effort by G.R.A.S. Sound & Vibration to update...

audioxpress.com

I'm a little confused here. Isn't Butterworth saying that the RA040X is better than the RA0045? If pinnas are non-standard, then is there an article that discusses a pinna'd RA040X and a pinnaless RA0045?

Figure 2: I measured the frequency response of the 1More Triple-Driver IEM with the G.R.A.S. RA0045 (blue trace) and the G.R.A.S. RA040X (red trace).

Conclusions
Measurements of headphones and earphones at frequencies above 10 kHz is in its infancy, but it appears to me that the G.R.A.S. RA040X will help improve this situation. The internal damping G.R.A.S. has added clearly helps reduce the magnitude of the main chamber resonance of the ear simulator, which should produce above-10 kHz measurements that, while not perfect, are certainly more trustworthy.

 

[USER]

Just wanted to add some more information about RA040X as things got a little muddied up. The main point is that it complies with IEC60318-4 according to GRAS itself. The whitepaper is available in the following link.

General IEM Measurements Discussions

Up on the blog now: Calibrating and Using a DIY Rig for Measuring Frequency Responses May 20, 2019 Jürgen Kraus, Biodegraded Call it work in progress. Your input will be welcome and appreciated.

www.head-fi.org

The question concerning the effects of the specific pinna is a separate issue and it I'd love to read anything conclusive about it. That all said, using EQ that is based on respective measurements to test them is still one of the best ways to judge results.

But at this point I personally don't see why I would want to "calibrate" (if you can call it that) to RA0045 over RA040X if there is the option. We all do the best we can in the moment we are in.

 

[MayaTlab]

Just wanted to add some more information about RA040X as things got a little muddied up. The main point is that it complies with IEC60318-4 according to GRAS itself.

Complies with IEC60318-4 =/= same measurements. When using the ear canal extension the length mode is shifted lower, resulting in the typical resonance you see around 6-10kHz for most IEMs. That resonance in particular will be different between the two couplers, and the transfer function may not be a constant across individual IEMs because it's a question of damping (You can't create a static compensation for it).

The RA0402 isn't necessarily better, it depends on what you want to do with it.

The question concerning the effects of the specific pinna is a separate issue and it I'd love to read anything conclusive about it.

That's what Brent Butterworth did at SoundstageSolo (pinna vs canal extension, same coupler), and what you see in the graph linked to above is the difference between some of the few IEMs he tested with both the pinna and the canal extension. You can see his reviews here : https://www.soundstagenetwork.com/index.php?option=com_content&view=category&id=263&Itemid=203

My take however is that the differences he found seem a bit exaggerated to me. Even with a clone KB50x0 pinna (and with a rather problematic mounting issue that may or may not be shared with the genuine article) I tend to get lesser differences, but with a rather constant trend nonetheless.

But at this point I personally don't see why I would want to "calibrate" (if you can call it that) to RA0045 over RA040X if there is the option.

It depends on what you want to do. Do you want to have a quick and dirty assurance that your own clone coupler is reasonably similar to a genuine RA0045 ? Then compare it to Oratory and CSGlinux (Hypethesonic) databases, preferably selecting for IEMs with a reasonably low sample and tip selection / mounting / positioning variation. How to interpret the data you obtain can be made easier if you have some idea of how ear simulators work in terms of equivalent volumes and some idea of how IEMs can be tuned (this will help in determining if a difference is more likely to come from the acoustic impedance of the coupler, the mic's FR, positional / seating variation, tip selection and mounting, or the IEMs themselves). Note however that this is an inherently noisy approach because of various factors. Ideally you'd be able to directly compare your clone with a genuine 711 coupler or even measure its transfer impedance - not easy to do in practice !

Nothing should prevent you however to create a transfer function with Amir's measurements if you so prefer, but just know that, contrary to the first approach, if the transfer function for individual IEMs is inconsistent, it could very well be quite normal (just like it's to be expected that it is inconsistent to some degree between type 2/3 - ie 711 - fixtures or type 4.3 - ie 5128 - fixtures, or even between an ear simulator and your own ears.

Some articles that could be useful on how couplers work :

https://www.bksv.com/media/doc/bn0221.pdf

https://www.aes.org/technical/documentDownloads.cfm?docID=177

https://espace2.etsmtl.ca/id/eprint/20020/1/Doutres%20O%202019%2020020.pdf

https://doc.comsol.com/5.6/doc/com.comsol.help.models.aco.generic_711_coupler/models.aco.generic_711_coupler.pdf

 

[markanini]

But at this point I personally don't see why I would want to "calibrate" (if you can call it that) to RA0045 over RA040X if there is the option. We all do the best we can in the moment we are in.

All I can say is that most who create deltas, "corrections", target equivalent systems (RA0045 to clone 711)in order to reduce individual difference between measurements from each rig. A more consistent delta also makes it easier to verify that the measurement was good and the coupler works as intended, the IEM measures within reasonable range of unit variation.

EDIT: I see now that MayaTlab has joined the discussion, he will provide a thorough explanation of recommended practices and the data behind it, I'm sure.

 

[USER]

I also want to say that one significant benefit of buying a coupler and playing around with it is that you really do get a good "feel" of who is good at producing measurements and can learn to intuit issues with the results and know what to ignore and sort of correct some things by eye. I am finding that I am able to be more consistent than I thought I would be early on in the process--though I have to be super patient and willing to measure 20+ times to get things as good as possible! In my case it is about being as precise with the 8kHz resonance as I can. (My posts are mainly for people thinking of buying a coupler if that wasn't clear.) It's easy to see that many on squig.link give up, though of course I myself have met fitting limits and have had to settle.

Here are two measurements from 2 different days. That is pretty decent considering I was not thinking of comparing the results when I made them.

I believe the slight differences are in some part due to the resonances not aligning perfectly. You can see it close-up in REW. But even this is pretty good. I certainly respect the better measurers more than I did before. I am excited to send Amir some IEMs that I have measured myself as that will help a lot.

Obviously this doesn't relate to getting perfect matches out of a conversion EQ between two measurement systems, but who expects that? Things are going to be different given all the variables but a good measurer provides a lot of details and and develops a good reputation. (Plus I can now see issues in some of Amir's graphs that I can ignore or differentiate them from general IEM performance differences.) Getting a good conversion EQ is the result of a mixture of careful analysis and common sense (the latter bettered by measuring a lot of IEMs oneself). I've already gotten a consistent conversion EQ between ASR and one of the better squig.link measurers so I am comfortable with the process and know what I want out of it. Right now I am testing many hardware and software set-up variables so that I can learn about the causes of anomalies and what they look like. I'm looking forward to comparing my Apple Dongle set-up to a high quality E1DA Cosmos one this weekend.

In the end I hope that people are not afraid to try this. The specter of technological limitations and unknown or uncontrolled variables certainly hovers, but unless one has an authentic coupler/set-up this is simply a hobby for amateurs. Certainly many youtube reviewers forget this when they take their own measurements too seriously and make really silly assumptions, especially concerning the higher frequencies. But I also find a strong link between poor analysis and "review" quality and people that very clearly did not ever compare their results to a more legitimate source.

Edit: I've said this before but maybe it bears repeating: I have no intention of reviewing IEMS, lol. I purchased the coupler to help me get the best performance out of my IEMs be it through tip changes or EQ. If this helps me post measurements on here that I am more comfortable presenting than I would otherwise, all the better. The $110 investment is a no-brainer to me.

I have worked on a phono cartridge measurement thread that I take very seriously and am proud of, however. So I am no stranger to imperfect measurements, lol.

Introducing the Phono Cartridge Measurement Library

After years of development we are finally launching our phono cartridge measurement library. These measurements were created using the brilliant cartridge response python script written by @scott wurcer and @JP. Information about its origins can be found in the following threads...

www.audiosciencereview.com

 

[markanini]

I also want to say that one significant benefit of buying a coupler and playing around with it is that you really do get a good "feel" of who is good at producing measurements and can learn to intuit issues with the results and know what to ignore and sort of correct some things by eye. I am finding that I am able to be more consistent than I thought I would be early on in the process--though I have to be super patient and willing to measure 20+ times to get things as good as possible! In my case it is about being as precise with the 8kHz resonance as I can. (My posts are mainly for people thinking of buying a coupler if that wasn't clear.) It's easy to see that many on squig.link give up, though of course I myself have met fitting limits and have had to settle.

Here are two measurements from 2 different days. That is pretty decent considering I was not thinking of comparing the results when I made them.

View attachment 364350

I believe the slight differences are in some part due to the resonances not aligning perfectly. You can see it close-up in REW. But even this is pretty good. I certainly respect the better measurers more than I did before. I am excited to send Amir some IEMs that I have measured myself as that will help a lot.

Obviously this doesn't relate to getting perfect matches out of a conversion EQ between two measurement systems, but who expects that? Things are going to be different given all the variables but a good measurer provides a lot of details and and develops a good reputation. (Plus I can now see issues in some of Amir's graphs that I can ignore or differentiate them from general IEM performance differences.) Getting a good conversion EQ is the result of a mixture of careful analysis and common sense (the latter bettered by measuring a lot of IEMs oneself). I've already gotten a consistent conversion EQ between ASR and one of the better squig.link measurers so I am comfortable with the process and know what I want out of it. Right now I am testing many hardware and software set-up variables so that I can learn about the causes of anomalies and what they look like. I'm looking forward to comparing my Apple Dongle set-up to a high quality E1DA Cosmos one this weekend.
View attachment 364358

In the end I hope that people are not afraid to try this. The specter of technological limitations and unknown or uncontrolled variables certainly hovers, but unless one has an authentic coupler/set-up this is simply a hobby for amateurs. Certainly many youtube reviewers forget this when they take their own measurements too seriously and make really silly assumptions, especially concerning the higher frequencies. But I also find a strong link between poor analysis and "review" quality and people that very clearly did not ever compare their results to a more legitimate source.

Edit: I've said this before but maybe it bears repeating: I have no intention of reviewing IEMS, lol. I purchased the coupler to help me get the best performance out of my IEMs be it through tip changes or EQ. If this helps me post measurements on here that I am more comfortable presenting than I would otherwise, all the better. The $110 investment is a no-brainer to me.

I have worked on a phono cartridge measurement thread that I take very seriously and am proud of, however. So I am no stranger to imperfect measurements, lol.

Introducing the Phono Cartridge Measurement Library

After years of development we are finally launching our phono cartridge measurement library. These measurements were created using the brilliant cartridge response python script written by @scott wurcer and @JP. Information about its origins can be found in the following threads...

www.audiosciencereview.com

Imagine how challenging achieving consistent measurements would be with a pinna attachment.

 

[USER]

This is looking to be a bit more straightforward than anticipated, though that doesn't mean easy answers, lol. The coupler seems to be performing well.

After correcting for this:

I get a good, consistent matches with oratory1990 (of results that more or less have the 8kHz resonance line up and which seem to be more recent).

It seems from comparing 3 different IEMs (and multiple copies of each) that the only important difference between these RA0045-based results and Amir's results (outside of the resonances, obviously) is this, roughly a 1.5 dB bump between 800-5kHz. Again, I am shocked by the consistency I am seeing. I thought the coupler was going to be a piece of crap, honestly.

Ironically, this seems like the opposite of what one of the graphs in the thread described.

I am going to measure a JBL Endurance Run 2 and compare it and EQ results to those of Sean Olive as best as I can. I plan on sending it to Amir, but who knows when he will get to it.

So I have to think about this some more. I have always had the suspicion that IEMs were brighter than what many results show. But this is only the start of my personal investigation to see what works best for me. This has been fun.