How to measure IEMs cheap for use with AutoEQ?

[USER]

Looking good so far ! If you have a deeper insertion IEM (ER2SE for example), it could be interesting to see how it compares as well - but in the case of the ER2SE seatings can occasionally be quite inconsistent when using the older-style tri-flange tips and sample variation isn't perfect either. Don't over-sweat the details, even comparing Oratory and CSGLinux's databases does not result in a perfectly flat transfer function.

Thanks for all the good info! In fact, I do have an ER2SE. I plan on measuring it once I am more confident as it is a rather intimidating IEM, lol.

Cheers.

 

[USER]

I think I know what I am going to do. As an important Old El Paso commercial once asked, "¿Por qué no los dos?"

 

[MayaTlab]

I want to measure everything again with my E1DA Cosmos next week.

I'm quite curious to see how your Apple dongle and the E1DA will compare in terms of FR. Looking forward to it !

Thanks for all the good info! In fact, I do have an ER2SE. I plan on measuring it once I am more confident as it is a rather intimidating IEM, lol.

CSGlinux measured his with the older-style tri-flange eartip that is no longer provided in the newer packages (but you can get it by chopping off the tube of the tips provided with one of their noise protection plugs). I don't know how Oratory measured them.

This eartip can occasionally lead to odd results depending on exactly how the flanges mate with the ear canal extension (same volume level, same earbud, same eartip, somewhat similar resonance, just different seatings where I deliberately tried to introduce "accidents") :

Also, sample variation for four earbuds (I had some difficulty with hitting the exact same resonance though) :

 

[USER]

I'm loving how easy it is to measure Bluetooth IEMs with REW.

These are so comfy and the little protrusion helps keep it on your ears. Typical "sports" FR with bass boost. Not crazy but the JBL app makes it super easy to correct and they sound terrific afterward. They clearly have the measurements so I don't know why they don't publish them. Maybe they figure it doesn't matter if people will use the app.

These are not my official distortion measurements as they are very simple captures and I will put-together a more appropriate set-up, but I figured that the peak distortion results are maybe sort of reliable and they are what really matters anyways. (Please correct me if I am wrong.) Seems rightish? JBL wireless IEMs were never meant to be played loud and these have clearly hit their limit. Here the measurements were taken at ~94 dB at 450Hz.

 

[markanini]

've been quite happy with the sample variation of the Moondrop Chu (1st gen) so perhaps add this one to your roster of test IEMs :

(this is each earbud compared to the dB average of all six.)

I would recommended getting Chu for learning how damping works in the front vent and nozzles, even more when you have a coupler and can measure the effects.

 

[USER]

I would recommended getting Chu for learning how damping works in the front vent and nozzles, even more when you have a coupler and can measure the effects.

Yup. I agree. I already have a vent plug mod measurement posted for the 7Hz Salnotes Zeros. (It's of my "hot rod" version with the vent covered and spring tips to boost the bass and smoothen the highs--ie. use them without EQ.) I posted some tip comparisons as well. I have some mesh filters that I will measure with the Zeros. It's nice to see videos about mods but so much more fun to test it on your own IEMS. That's why I got the coupler to begin with.

 

[Gershy13]

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

Skip to the index. 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 the legendary @scott wurcer and @JP. Information about its origins can be found in the...

www.audiosciencereview.com

I'm considering getting one just to help me make decisions about EQ and tips too. Are the measurements reliable up to 20khz? I see places say that they aren't accurate above around 10k, but for relative measurements would this be okay? Say if I have two items and I want to compare their performance even in the upper treble. Or check the difference between silicone and foam tips on a planar iem that I find too bright etc.

 

[USER]

I'm considering getting one just to help me make decisions about EQ and tips too. Are the measurements reliable up to 20khz? I see places say that they aren't accurate above around 10k, but for relative measurements would this be okay? Say if I have two items and I want to compare their performance even in the upper treble. Or check the difference between silicone and foam tips on a planar iem that I find too bright etc.

If I remember correctly these measurements are not to be taken seriously after 10kHz. (All GRAS measurements??) But even below that is not necessarily what you are going to get because things like ear canal shape and tip insertion depth change the results. Here, with the coupler, insertion depth shifts the resonances around and the areas around them. The best we can do is adjust insertion depth so that the main resonance is as close to 8kHz as possible. You can kind of understand now how this is a troubling scenario as we may not even insert our own IEMS the same way the same day. Sometimes it is not possible to hit 8kHz (it is easier to do this with the coupler sideways) because of the tip and/or IEM design so you do the best you can but a good rule to follow is that you should ignore measurements that don't hit 8kHz resonance as they don't make apples to apples comparisons so to speak. More, cheaper couplers like these show stronger and more disruptive resonances that show more "negative space" around them than is actually there. Certainly ignore a measurer that is not consistent because it shows laziness as it can take many, many tries to get results right. Nonetheless I think these are great for those type of decisions you mention because you can compare your results to each other to see the effects in a contained system. I think my coupler is the best IEM-related purchase I have made. I've learned a lot about IEMs and also now better read and understand measurements.

 

[USER]

Forgot to mention perhaps the best reason to get a coupler: to find issues you may not have confidence in determining are there otherwise.

In all honestly, I had no idea one channel was off with this set. Part of this is that I took what I was hearing for granted after years of use and also the fact that I only use wireless IEMs sporadically in specific situations. As you can see, I couldn't hit the 8kHz resonance with these.

When I ordered these through Amazon and from Linsoul I received a set that was clearly used. These companies are well-known for trying to sneak out used items when they can. I immediately set-up a return but held on to them for a few days in order to test them. I don't know if it is a coincidence or not, but the previously returned set has a slight channel imbalance. The brand new set is pretty much perfect. Is it a big deal? Probably not. But I always want to know how far off my IEMs are.

This is a cheap set that I purchased to practice measurements with. I am now better equipped to hear this issue.

If you are the type of person that spend hundreds on or continually purchases IEMs I think it is unwise to not to buy a measurement rig for about $120. Seeing as there are so many small boutique brands, I personally want some extra reassurance regarding my respective purchases. Same goes with refurbished items and used goods. You have to be able to rely on yourself to make sure what you buy is of good quality.

 

[Gershy13]

If I remember correctly these measurements are not to be taken seriously after 10kHz. (All GRAS measurements??) But even below that is not necessarily what you are going to get because things like ear canal shape and tip insertion depth change the results. Here, with the coupler, insertion depth shifts the resonances around and the areas around them. The best we can do is adjust insertion depth so that the main resonance is as close to 8kHz as possible. You can kind of understand now how this is a troubling scenario as we may not even insert our own IEMS the same way the same day. Sometimes it is not possible to hit 8kHz (it is easier to do this with the coupler sideways) because of the tip and/or IEM design so you do the best you can but a good rule to follow is that you should ignore measurements that don't hit 8kHz resonance as they don't make apples to apples comparisons so to speak. More, cheaper couplers like these show stronger and more disruptive resonances that show more "negative space" around them than is actually there. Certainly ignore a measurer that is not consistent because it shows laziness as it can take many, many tries to get results right. Nonetheless I think these are great for those type of decisions you mention because you can compare your results to each other to see the effects in a contained system. I think my coupler is the best IEM-related purchase I have made. I've learned a lot about IEMs and also now better read and understand measurements.

Thanks, yeah i know that after 10k it gets a bit eh. But i was wondering if that was only when comparing to other measurements/your ears. Basically my question is will it be accurate for 10khz+ for relative measurements? If i matched the 8k resonance on both? Or say i dont even move the iem for both measurements, i just change something at the source (EQ, impedance adapter, etc) Would these results show up on the graph even for above 10k? For relative measurements could it be compared?

 

[USER]

Thanks, yeah i know that after 10k it gets a bit eh. But i was wondering if that was only when comparing to other measurements/your ears. Basically my question is will it be accurate for 10khz+ for relative measurements? If i matched the 8k resonance on both? Or say i dont even move the iem for both measurements, i just change something at the source (EQ, impedance adapter, etc) Would these results show up on the graph even for above 10k? For relative measurements could it be compared?

I would think that it would be good enough for comparisons and that differences would be easy to see, especially for our use case, but I will be the first to admit that we are getting into a realm that is past my limited knowledge of the subject matter. I just don't know too much about performance past 10kHz. Hopefully someone can shed more light onto the question.

 

[USER]

Dongle comparisons and "USB soundcard" measurements

As I have not seen a direct comparison elsewhere I am posting this so that it helps folks get good results with the cheapest measurement set-up possible (using the Apple USB dongle).

I purchased an E1DA 9038D6K dongle to replace the Apple USB one but as I rushed things from excitement I didn't realize that it doesn't offer an input option, which is very lame as the Apple dongle does and it costs only $8.

The graph below is a comparison between the Apple USB as both output and input, the E1DA as output and the Apple as input, and finally the E1DA as output and the small USB soundcard that is sold with the coupler as the input. Here E1DA and APPLE should be considered a match.

The only difference is found in the low end. You can ignore the differences above 100Hz as they are due to minor vibrations during measurement. I recommend using the Apple USB dongle with correction as it has a MUCH LOWER noise floor than the USB soundcard, is easier to use, and is cheaper. I'd like to figure out a way to use my E1DA Cosmos as an input but right now the only way I can do so is with a TRS transforming adaptor for phantom power. Unfortunately these adapters introduce noise and that sort of defeats the purpose of using the E1DA, but I will try it out eventually. I'd love to see the noise measurements for the B&K conditioner many good measurers use but I just don't see it being worth the money over the Apple USB dongle. Distortion measurements are essential in my opinion but I think we only have to find issues, and for that you only need something good and not necessarily great.

All you need to correct Apple USB dongle measurements is a simple PK 20Hz, 2.3dB Gain, 0.8 Q adjustment.

Edit: For further clarification, using either the USB soundcard or the top-of-the-line E1DA dongle as the output makes no difference for the frequency response, which is a good thing as a lot of the measurements on squig.link use the former.

Edit 2: Very basic measurements of the little "USB soundcard." I adjusted it to the volume I use to get 450Hz on the IEM as close to 94 dB as possible for a fair comparison. Noise is at -83 dBFS here. Hope this all helps.

Edit 3: Added a Zoom H1n recorder to the mix. The E1DA dongle is the source feeding the IEM for all three. It is worse overall.

 

[USER]

Focusrite Scarlett 2i2 4th Gen Results.

I had to replace my desktop microphone interface so I decided to take advantage and see how the new Focusrite Scarlett 2i2 4th Gen performs with the coupler. Here are some mic input FR measurements I was able to find. Note the different gain settings. These results are considered very good for audio interfaces.

Unfortunately using a BNC to XLR adapter with the coupler mic gave me these results.

I am not sure if the issue is that the connector was wired incorrectly or not. Perhaps it has to do with the voltage output or phantom power incompatibility. Any information or advice is welcome as I would ideally like to use the coupler with such a connector

And so I was forced to use a Rode VXLR+ XLR to 3.5mm Female TRS Transforming Adapter.

It seems to work for FR. Not sure how much distortion it is adding right now. Here are the results of the 4 measurement interfaces I have tried. Gain was at 30, which is a little under 50% gain.

The "USB Soundcard" and this Scarlett 2i2 set-up are pretty darn close. I do not know if the Rode VXLR+ is having an effect on the FR or not as it could have some effect on impedance that I cannot measure. Obviously I cannot say that this result is representative of the "Scarlett 2i2 4th Gen" as I have to consider the adapter, but it's useful info nonetheless.

Addendum: Finally, here is the result of the Apple Dongle correction EQ mentioned in the post above (on a new measurement just taken with the Apple USB as both output and input) compared to the E1DA to Scarlett 2i2/Rode VXLR+ measurement.

Again, the concern here is the small difference below 50Hz --of half a dB!!! Technically I can't say that the Rode VXLR+ didn't make a difference as I can't offer evidence. But it certainly looks about right if we consider that mic input FR posted above. Hell, it could even be a tiny bit closer if I spent more time getting the IEM insertion to match better! In addition, my corrected Apple measurements match Amir's results in that region (and one of Sean Olive's as well). They use different couplers but this now seems to me to be something that relates to interfaces and not the couplers. I'm going to assume that their interfaces have tighter tolerances than those of reviewers, especially as I've not seen any measurements of that aging B&K conditioner. Consumer interfaces caught up a long time ago.

Nonetheless, I am growing much more confident in the typical "USB Soundcard" measurements popular on squig.link, with the caveat that this assumes the respective measurers know what they are doing. I am thinking too that the Apple USB dongle with correction is a reliable approach, though I need to test the correction EQ against more measurements made with the USB Soundcard as I don't know how much the former's FR changes with different gain settings.

 

[USER]

Does anyone know if I should be using the default "use harmonic frequency as reference" option in REW when graphing distortion? Turning it off lowers the results above 1kHz (though it does not necessarily raise the low end like in this example). With the latter option and with better examples the results are more in line with Amir's.

 

[USER]

File this under "what the heck do I do with this?"

Like the Salnotes Zeroes, these have a small vent right by and under the tip. My guess is that it was tuned so that it is in some way covered when inserted into the ear. I'm thinking that the Zeros are meant to function similarly. (This also makes them a bit better than what normal measurements would say.) However the swings here are wild and we have ourselves a mess. How are you going to have consistency here? Between insertions? Between ears? How do you measure these? In real life use they have much more bass than what the blue line says. I'm glad I decided to measure them again with the vent closed instead of simply throwing them away. I think I learned something.

Focus only on the area below 100Hz. Normal use should likely be closer to the green curve.

 

[staticV3]

Does anyone know if I should be using the default "use harmonic frequency as reference" option in REW when graphing distortion?

This page has a detailed explanation of that setting:

Distortion Graph

It's yet another tweak to traditional THD measurements that tries to make them more relatable to human hearing. Some other examples are Klippel's Characteristic Harmonic Distortion or rtings' Weighted Harmonic Distortion.

For compatibility with other measurements from Amir, Erin, Solderdude and co. I believe this setting should be turned off.

 

[USER]

This page has a detailed explanation of that setting:

Distortion Graph

It's yet another tweak to traditional THD measurements that tries to make them more relatable to human hearing. Some other examples are Klippel's Characteristic Harmonic Distortion or rtings' Weighted Harmonic Distortion.

For compatibility with other measurements from Amir, Erin, Solderdude and co. I believe this setting should be turned off.

Thanks so much!

 

[USER]

I have something cool coming up. Hoping for some interesting problems, lol.

Air Tube headphones. Used by a few in broadcasting and, increasingly, paranoid conspiracy theorists concerned about "radiation" and spying! Hahahaha.

Any guesses as to how they sound? Will it be possible to EQ them and make them sound good?

 

[markanini]

I have something cool coming up. Hoping for some interesting problems, lol.

Air Tube headphones. Used by a few in broadcasting and, increasingly, paranoid conspiracy theorists concerned about "radiation" and spying! Hahahaha.

View attachment 368873View attachment 368874

Any guesses as to how they sound? Will it be possible to EQ them and make them sound good?

I predict they will be highly distorted in the frequency responce.

 

[USER]

UGreen Hifi Audio USB C dongle results

Just in case anyone is interested. This is the fancier dongle UGreen puts out now, which replaces the venerable 80583 HiFi Audio Pro (as a bit of a downgrade). Technically this is the dual-pronged car version with a power input, but I imagine it is the same as the standard one.

Might there be a high pass filter in the mic input? Something to consider with dongles I suppose.

Output is fine, which is good news for my car.