IEM's - Where do diminishing returns start - cost wise? $10, $15, $20, $30, $50, $200, etc, etc

[OK1]

Value for money, the budget KZ/CRA is very hard to ignore. One challenge is it's impossible to know what an IEM sounds like, until you order on and hear it for yourself.

I am 100% satisfied with the CCA CRA - V 2. I find it extremely revealing, without being fatiguing. Have just ordered another one for my significant other, for her casual listening use cases. And a KZ ZVX as my next IEM along the rabbit hole. So with the CCA CRA - V 2, and a KZ ZVX, that should be more than enough to meet my immediate needs for the foreseeable future.

Youtube was especially helpful to understanding the evolution of the KZ/CRA products. So many products, and many have received good reviews, some outstanding reviews. And it does take time to correlate the info from Facebook, Youtube and the various KZ web sites.

Special mentions are the KZ ZVX, KZ D-Fi, Kz Krila, KZ Castor, KZ Merga, KZ Vader, CCA Polaris, CCA Pianist amongst the budget priced range. I may have left out one or two, but definitely all these are very highly rated, and while not identical in Frequency response, they should provide satisfactory listening, and each is targetted to a specific kind of listener - Bass lovers, Neutral Flat lovers, or Treble heads, to an extent. So enough decent options to choose from.

From now on - I'll do my best to keep abreast of the market, and see if, for a token, I can test the waters again, and about every 6 months see where the current diminishing returns starts., and acquire something new. But soon enough it will become once a year, otherwise one just builds a collection of IEM's which are unutilised, like cars - most of us need only one - Can't sit in two cars at the same time!, same with headphones. Can only listen to one, at a time.

The CCA CRA is where I think diminishing returns starts. Typically available for less than $15 if you know where to buy, and it can be delivered to your country. (excluding import taxes if these apply) - Sound quality equivalents would be things like the Moondrop Chu/Chu II, 7hz Zero... or revisions thereof IMHO.

And then next up the ladder would be one of these - KZ ZVX/KZ-D-Fi/KZ Krila/KZ Castor/KZ Merga/CCA Polaris (or equivalents from other manufacturers) depending on personal preference in frequency response.

I think beyond these sound quality really starts to diminish.

Overall - thanks to KZ and associated businesses, price and performance no longer have a strong correlation. There are inexpensive IEM's that, from what reviewers say, should sound as good and sometimes better than competing alternatives, which could be as much as 10 times the price.

 

[Basic Channel]

I would buy the 7hz zero or moondrop chu for a few extra shillings than take a chance on one of the endless list of KZ models, especially as they have history of being shady.

 

[OK1]

Depends on what the IEM is going for; diminishing returns on single-driver IEMs kick in almost immediately, maybe even down to $15 with how the Chinese brands are moving nowadays. It's not to say expensive IEMs are all ripoffs (I stand by my feverish meatriding of the 64 Audio U12t), or that there's no reason to ever get one, just that in the old days you used to have to spend out to get something good, and now you don't.

My girlfriend's cat chewed through the Moondrop Free DSP cable I was using to listen to my new CVJ Konokas, so I went to Best Buy and got a USB-C to 3.5mm adapter and was blown away by how much worse it sounded. That's $10 vs. $30.

It's fantastic that, with a bit of effort and research, if one comes to the right place e.g this online community, one is able to glean what is the current state of headphones, and all things audio (especially on the consumer side of things - hi-fi, and all that), to make better purchasing decisions.

I'd put the 1st threshold of diminishing returns somewhere between a max of $15 and $20(including delivery and customs), which gives pretty much many people access to a wide choice of about, 15 different, good sounding IEMs, that one could recommend with confidence, that are definitely value for money - based on reviews. Actual price would depend on things like sales., and ability to order products from China and have them delivered in country. We assume Amazon, which is usually the most expensive online store for IEM's, is available everywhere, but that is not true.

Included in that list, in no specific order of preference, in the $15 to $20 max price range, off the top of my head, would be :

1. Moondrop Chu I or II
2. 7Hz Salnotes Zero or Zero 2
3. CCA CRA or the latest revision
4. CCA CRA+
5. CCA CRA Pro (a new one just out)
6. CCA EDA Balanced
7. CCA Lyra
8. CCA CXS
9. CCA Polaris
10. CCA Pianist
11. CCA Duo
12. CCA Trio
8. KZ ZVX
9. KZ D-FI
10. KZ - Castor Harman or Harman + BASS
11. KZ Krila
12. KZ Merga
13 KZ Vader
14 KZ ZSN Pro
15 KZ Ling Long
16 TRN Orca

Pretty sure there are at least another 10, one could add to the list, to make up to 25, The Tangzu Wa'ner, one of the Truthears etc, etc. That's 25 budget IEM's which one could say - just choose any one of these and you are assured of a decent sound, to get you going, without spending too much, but depending on your personal preferences, you may want another item in this list. I'm more familiar with the KZ and CCA 's cos that's where I spent most recent efforts in research, to understand their model trends.

The only other thing in this category of headphones would be to categorise them into tonal groups, based on frequency response. - V shape, Harman, U shape, Neutral, Bass Heavy, Mid focussed, High Frequency Prominent, and a headphone could have more than one frequency response derived attribute.

I've bothered to put this list up, cos I wish when I was starting out, I had such a shortlist or guaranteed to sound more than good enough, and affordable IEM's. This would have saved me a lot of time in trial and error, and research.

This in itself is a bit of a revelation, that we have so many good sounding IEMs, in the budget category, that are as capable or better than the CCA CRA, which I would consider the absolute minimum in quality, there is no point spending any less, trying to save money, cos that would be penny wise pound foolish.

Which brings me to another point - diminishing returns works both ways. It would be the points at which spending more may not produce an improvement corresponding to the amount spent, but this could also be the point where there is no reason to spending any less, cos its like throwing good money after bad.

A key trend clearly is that over time, the new products tend to be better, than much older products, in the same category of transducer type - e.g dynamic drivers, guess cos of better research and more customer feedback, over time.

 

[OK1]

I would buy the 7hz zero or moondrop chu for a few extra shillings than take a chance on one of the endless list of KZ models, especially as they have history of being shady.

I think from my experience, we should have moved past that history. Not worth dwelling on the past. If you think of it, what was their crime - exaggerated marketing claims.

They put in drivers in a headphone that were not used actively. So what - at least the drivers were there. It was not like they lied and did not put in the drivers! And the headphone sounded good. It was not a bad sounding headphone. !! It sounded so good, no one was the wiser.

I think what's more important is that we should evaluate the end result. I can attest that the end result of the only KZ family IEM I have listened to, is spectacular, and really the only reason to buy any other is FOMO, or what I would call headphone education, cos most of us will not know what these things sound like, until we purchase one for ourselves.

I also was apprehensive, but many of KZ's most recent family of IEMs have been reviewed by many credible online reviewers, in text or in video. We can be sure there is unlikely to be any funny stuff going on. Besides, their IEM's are so well priced, and now also very well built, that the only one hurt by ignoring KZ and its family of IEM's, would be us. Everyone else who has recently bought into their brand, would be smiling home to the bank, and achieving a great listening experience. Had the CCA CRA for about a month and my impression of it gets better by the day, so good, I've ordered one for my wife, and ordered a KX ZVX for myself.

Suggest you try one out. Fortunately they are so well priced, that's one more reason to no longer hold out against KZ.

 

[Ken Tajalli]

I don't know about IEMs but I assume that they are like headphones in-that you don't exactly get "diminishing returns", but that there is almost no correlation between price and sound quality. With headphones, You can spend more... a lot more... and sometimes get worse sound quality.

I am with you on that, price and final sound quality have no correlation.
And no measurement can tell you how an IEM will sound to you. The only informative bit is the distortion curve, if you can have low distortion, smooth curve, that tells you there are diaphragm breakups or resonances.
Good build quality, the distortion curve, smooth enough FR (forget the Harman curve), and reputable manufacturer, that is my starting point.
Then, price and listening comes second.

 

[markanini]

I think from my experience, we should have moved past that history. Not worth dwelling on the past. If you think of it, what was their crime - exaggerated marketing claims.

They put in drivers in a headphone that were not used actively. So what - at least the drivers were there. It was not like they lied and did not put in the drivers! And the headphone sounded good. It was not a bad sounding headphone. !! It sounded so good, no one was the wiser.

I think what's more important is that we should evaluate the end result. I can attest that the end result of the only KZ family IEM I have listened to, is spectacular, and really the only reason to buy any other is FOMO, or what I would call headphone education, cos most of us will not know what these things sound like, until we purchase one for ourselves.

I also was apprehensive, but many of KZ's most recent family of IEMs have been reviewed by many credible online reviewers, in text or in video. We can be sure there is unlikely to be any funny stuff going on. Besides, their IEM's are so well priced, and now also very well built, that the only one hurt by ignoring KZ and its family of IEM's, would be us. Everyone else who has recently bought into their brand, would be smiling home to the bank, and achieving a great listening experience. Had the CCA CRA for about a month and my impression of it gets better by the day, so good, I've ordered one for my wife, and ordered a KX ZVX for myself.

Suggest you try one out. Fortunately they are so well priced, that's one more reason to no longer hold out against KZ.

To me it's about sampling the competition before picking favorites. At the same time KZ did continue making silent revision to product as recent as PR2 in 2023. Even if I'm probably more charitable than the average KZ criticizer. KZ has relationships with various suppliers and obligations to various retailers. When a supplier drops the ball mid-production they will have hard choices to make. But that's what it is. There's also a question of incentive. KZ as a brand established itself on the market relatively early. Other brands had to bring something to the table and surpassed KZ in tuning quality IMO. At this point KZ doesn't lose money if their tuning is subpar due to market forces.

 

[OK1]

To me it's about sampling the competition before picking favorites.

When I started this IEM journey, I had intended to spend about $60 one one. So the CCA CRA I bought was not based on any research whatsoever. I had heard of the product, and knew the typical price on Amazon. What pushed my buttons was the price on AliExpress. Could not believe my eyes. Instant buy. Less than $15. I do not recall reading a review or watching Youtube review - just bought it.

I recently spent more than that - equivalent to about $25 cos I'm in the UK, and a pound has higher value than the dollar, so I have to convert, on the Apple Earpod - wired, which in comparison, sounds nowhere as good as the CCA CRA.

I bought some cheap ear bud type and some really entry level Sony headphones, for between $7 and $12, that sound completely like rubbish when compared to the CCA CRA, which I bought with no great expectations. Now I have to question myself, why spend more than $25 on an IEM?

It's such a hard thing now for me to think of buying anything from the competition - cos of the price. For $30 I can try out TWO KZ's or CCA's, that I know will sound great, and most likely better, than the CCA CRA I already have, if multiple reviewers are to be believed cos one thing I can say is than on the KZ family of products, there is so much convergence between the measurements and the subjective opinions of many reviewers.

There is a parallel in the professional audio industry - Behringer. Once upon a time, and less so nowadays, many of their products were just cheap - I had little money and I also bought some, but their quality was not the best. It worked. And they manufactured in China, to lower costs. Over time they gained such market share and had the cash to buy over brands which were once bigger than them, such as MIDAS and Klark Technik. A compelling success story.

The KZ family goes one better. Many of their products actually are technically good, and sometimes better than competition, at a price no one can compete against them. They have decided what segment of the market they will target. I'd love to get the Artti T10 and a Moondrop Chu II , an Aria or a Hexa, but the budget KZ family's value is compelling. I will eventually sample the competition, but prefer to use some of that money 1st to round out my "education" on the KZ family - most likely at least two or three more products - A KZ D-FI - OR A CCA Polaris, A KX Castor Harman, and then there is this new one I just discovered today on Youtube - a CCA CRA Pro - what is that? Curious. They have turned me into a kid in a candy store, getting harder to focus on one item in their inventory.

In many ways KZ products are their own worst enemies. Their budget gear has prevented me from considering their own higher end, i.e anything above $30, I'm not complaining.

 

[muza_1]

You can add the TRN Orca to the low-cost alternatives it has become my favorite in the category. I got them for $11 on sale.
They are ceramic coated metal, has 3 switches and the cable is a bit better (braided) than the KZ one.

 

[herr.jemine]

well, I have a lot of cheap IEMs and some in the range of 100-300€ you can hear the difference, MP145, KZ AS24 or Timeless AE are clearly in a different league, they are very pleasant to listen to, my 7Hz Zero2, 7Hz Sonus KZ Castor, and Chu II are rotting away - The KZ AS24 are really cool - I'm impressed

 

[muza_1]

well, I have a lot of cheap IEMs and some in the range of 100-300€ you can hear the difference, MP145, KZ AS24 or Timeless AE are clearly in a different league, they are very pleasant to listen to, my 7Hz Zero2, 7Hz Sonus KZ Castor, and Chu II are rotting away - The KZ AS24 are really cool - I'm impressed

For me is the other way, I recently returned the Hydro and the Explorer and I've tried some up to a couple of thousands (64Audio from a musician friend) but mostly in the $200 range and non of them did it for me, it might have to do with me though to me sound stage is not a thing all IEMs sound more or less the same just the sense of space changes a bit also "technicalities" (detail, speed, micro detail (!?!?), 3D or orbital presentation, et al) are not a thing along with lush, mature, sophisticated, grown up, etc, to me only frequency response, distortion (to a lesser degree) and how that interact with your ear (fit) matters.

Also I like single DD over hybrids or multi-driver I might like planars too but its been a while since I tried one (isolation was a problem then I might try a modern one).

I tired so many IEMs over the years and to be honest I've almost reached my limit is frustrating and tiring I wish it was as easy as it's for speakers nowadays, find a good measuring one spend some time setting up and then don't give them a second thought all wilderness is part of the recording not the speaker fault.

But that is just me YMMV.

 

[OK1]

You can add the TRN Orca to the low-cost alternatives it has become my favorite in the category. I got them for $11 on sale.
They are ceramic coated metal, has 3 switches and the cable is a bit better (braided) than the KZ one.

Noted I'll add this to the list. Unfortunately the opportunity to edit a post expires after a while, But I'll make an effort to post a revised list every so often, of the 1st tier of the budget range.

 

[OK1]

well, I have a lot of cheap IEMs and some in the range of 100-300€ you can hear the difference, MP145, KZ AS24 or Timeless AE are clearly in a different league, they are very pleasant to listen to, my 7Hz Zero2, 7Hz Sonus KZ Castor, and Chu II are rotting away - The KZ AS24 are really cool - I'm impressed

The major challenge with listening devices, how does one quantify this difference, in a way that it can be measured. And is anyone measuring the characteristics that can predict this difference.

About 30 years ago, in the speaker arena, measurements were not such a big deal, but in today's world, due to research, there is a strong correlation between the measurements of a speaker and the expected response to the listener.

My hope is that there would be a similar opportunity with headphones/IEMs.

It is easy purely based on measurements, to demonstrate why some speakers may cost 20 times other speakers. Purely using measurements, however small the improvement, it's very demonstrable. Now each buyer has to decide if it's worth the extra cost, or not, to them, to buy a better speaker.

With headphones/IEM's we are still, in my opinion, in a bit of an exploratory phase, where we do not have ALL the info. I give an example - simple things like frequency response measurements not being accurate above a certain frequency, due to resonances inherent in the measurement gear. There is also a dearth of available measurements, for many aspects of a headphone's performance

Here are some measurements that I wish could become "standard", by those who review headphones/IEM's, so that we can eliminate more of the subjective opinions.

Reference music tracks for subjective evaluation of speakers and headphones

I, purely by accident, rather than premeditation and extensive review, became the owner of a CCA CRA pair of IEMs. Also known as the CCA CRA v2 or silent retune, amongst other informal monikers. It completely changed everything I know about headphones. But what shocked me the most was its...

audiosciencereview.com

I have massively benefited from objective measurements, when purchasing products such as microphone preamplifiers, ADC/DAC's, Audio interfaces, Dongle DAC's, headphone amplifiers, and next time I have the chance to upgrade my speaker, I'd be most inclined to follow the science predominantly. Unfortunately we are not quite there, in the case of headphones/IEMs

When it was time to buy dongle DAC's(or a Desktop DAC), I had three broad sets of criteria - Features, Sound Quality based on measurements - especially independent measurements, and Cost. Built a huge spreadsheet which tracked about 30 attributes per DAC. It was so easy to decide, cos the quality was all boiled down into numbers, I could compare, order by, filter, etc. And I'm 100% pleased with what I ended up buying, and I have not had to accumulate a bunch of DAC's, to evaluate them. I fully trusted the independent measurements (and the manufacturers published measurements which also agreed with the independent one).

Headphones/IEM's should be similar, we should just be able to look at the data and pick the one that's best for us, and have at least a good chance that we'll pick the right one.

 

[OK1]

well, I have a lot of cheap IEMs and some in the range of 100-300€ you can hear the difference, MP145, KZ AS24 or Timeless AE are clearly in a different league, they are very pleasant to listen to, my 7Hz Zero2, 7Hz Sonus KZ Castor, and Chu II are rotting away - The KZ AS24 are really cool - I'm impressed

I 100% believe you and think what should be possible would be building a list that enables different tiers, from budget to more expensive one's. If only it has quantitative measurements, that would be amazing, so one could sort what one wants based on specific criteria, such as cost and audio quality(whatever is able to measure that objectively)

 

[herr.jemine]

I 100% believe you and think what should be possible would be building a list that enables different tiers, from budget to more expensive one's. If only it has quantitative measurements, that would be amazing, so one could sort what one wants based on specific criteria, such as cost and audio quality(whatever is able to measure that objectively)

Measuring frequency response and distortion is certainly helpful at first, but it's not like listening to music. Music can be very complex, so I think resonances and distortion can then arise that weren't detected by simply measuring the sound with frequency response tones.

 

[OK1]

Measuring frequency response and distortion is certainly helpful at first, but it's not like listening to music. Music can be very complex, so I think resonances and distortion can then arise that weren't detected by simply measuring the sound with frequency response tones.

The only reason I am hoping that these approaches of translating measurements to a prediction of a speaker's performance, and that this could be applied to headphones/IEM's, is because in other areas of audio where I have a keen interest, as a live audio engineer (aka sound engineer for live events) as well as in my hobby and part time profession as a studio engineer, measurements have been very successfully used to predict speaker performance.

I.e just by looking at the various measurements, so much of the subjectivity of evaluating a speaker, can be taken away, and at least for the purpose of shortlisting what to buy, it is easy to eliminate the worst offenders that are not worth considering. Measurement also objectively takes away any issues with my own hearing, i.e. I may not be able to hear the issue, but at least the measurement will let me know - if there is something wrong, that I have missed.

In my work as an audio engineer, I use my ears, but I also use audio analysers that tell me visually, if there is something I may not be hearing, due to possibly limitations in my speakers, such as the low low end, that is poorly reproduced in my speakers, or there is some low level noise in silent regions of the music, which I should ideally take care of, even though it may be inaudible.

Considering that there are far more people who listen on headphones and IEM's and earbuds and earpods, and so many are now on wireless things in their ears, we are talking millions if not billions of people, I am a bit surprised that there has not been the same kind of effort to quantify and measure things we put on our heads, as there has been for speakers. Maybe it is because of the value - a really good speaker will be in the $1,000's of dollars per pair, compared to head things that cost probably less than $300. Also maybe the consumers who buy all these head things, are not as concerned and its only a small minority of audiophile buyers who bother with these listening quality details.

If you look at the number of followers of head thing reviewers, on Youtube, we are a pretty small community, even smaller than the professional audio engineering community. i.e we who are bothered about audio quality, are still bit of a small niche market. Most people, like other members of my family are not bothered. As long as it makes some sound, they are ok with it. !

There is one important reason though why I think one should bother with audio quality in "head things". Similar to my experience with Live audio speakers, and speakers or headphones in a studio, the better one makes the listening device one uses, the lower we can listen to it. So one really good reason, why I think the world should bother to produce and use better head things, is to prevent hearing damage. With a really good headphone, we can lower the level of the audio, and still hear all the details, and in a world where people use headphones for hours and hours each day, this should prevent hearing damage.

 

[InfiniteJester]

Most people, like other members of my family are not bothered. As long as it makes some sound, they are ok with it. !

This never stops to shock me.

Most people really think that the difference is almost insignificant between a terribly tuned headphone/speaker/IEM and an exceptional one. As long as something produces sound, they mostly don't care. Extremely bloated bass that bleeds into the mids? Doesn't matter. Extremely V shaped? Veiled vocals? Insane sibilance? Audible THD? What is that?

I will go even further. I was also a studio technician and I have recorded a lot of albums. I have recorded several classical piano albums. In one occasion, it was a collaboration with multiple pianists. One of them didn't trust my process and insisted on mixing his tracks himself.

Later, when the album came out, he was pissed off because people told him that his tracks were the worst sounding from the album. And he accused me of doing something to them.

No, I didn't do anything to them. I had to explain. Why you or this people that you mention think that they sound worse?

He couldn't put it into words, he just thought that they sounded worse than the rest.

I made him compare his files with the album. The sound was the same. After listening for a while, I asked him again.

Why do you think that they sound worse when you compare them to mine.

He was more calmed now that he had discovered that I didn't do anything to his tracks. But, still, he couldn't tell what was wrong.

He had mixed his tracks in mono! And neither he nor anyone in his family of musicians could tell what was wrong! Only when they listened to my tracks recorded at the same place with the same piano they thought that there was something different, but they couldn't say what!

 

[Mikig]

since we're talking about it...

what should you look for in an iem headphones. I assume given the shape that my AirPods 2 are. I don't really have experience with headphones in general. Today, I decided to use them to listen to music, given the day of rest. Normally I only use them for making calls. I'm amazed by the noise canceling function,
it seems like the world out there turns off... very strange feeling.
The music is pleasant, but I'm used to systems with speakers so I have no terms of comparison.
How do they position themselves in the IEM market? Are they good or can I find something much better?

 

[OK1]

This never stops to shock me.

Most people really think that the difference is almost insignificant between a terribly tuned headphone/speaker/IEM and an exceptional one. As long as something produces sound, they mostly don't care. Extremely bloated bass that bleeds into the mids? Doesn't matter. Extremely V shaped? Veiled vocals? Insane sibilance? Audible THD? What is that?

I will go even further. I was also a studio technician and I have recorded a lot of albums. I have recorded several classical piano albums. In one occasion, it was a collaboration with multiple pianists. One of them didn't trust my process and insisted on mixing his tracks himself.

Later, when the album came out, he was pissed off because people told him that his tracks were the worst sounding from the album. And he accused me of doing something to them.

No, I didn't do anything to them. I had to explain. Why you or this people that you mention think that they sound worse?

He couldn't put it into words, he just thought that they sounded worse than the rest.

I made him compare his files with the album. The sound was the same. After listening for a while, I asked him again.

Why do you think that they sound worse when you compare them to mine.

He was more calmed now that he had discovered that I didn't do anything to his tracks. But, still, he couldn't tell what was wrong.

He had mixed his tracks in mono! And neither he nor anyone in his family of musicians could tell what was wrong! Only when they listened to my tracks recorded at the same place with the same piano they thought that there was something different, but they couldn't say what!

Interesting and also very funny.

 

[muza_1]

Measuring frequency response and distortion is certainly helpful at first, but it's not like listening to music. Music can be very complex, so I think resonances and distortion can then arise that weren't detected by simply measuring the sound with frequency response tones.

Simply measuring the sound is what measurements are all about and tones are the best thing we have and there is no proof that they are not enough along with distortion to profile the sound of an IEM, there are a lot of anecdotes, same goes for technicalities* but nothing concrete.

The measurements are taken at the nozzle so all distortion and resonances made it there so they can be measured.
Now your own ears and how they react to the IEM design is a different story and can only be found out by measuring them or trying out the set and see if it works our for you.

I said in the past that there might be something affecting the sense of space in IEMs but I meant it as a function of the system as whole (IEM, tip and ears) and therefore different for everyone and that do not appear in the measurements (how can it, the fixture is different form your ears), fixtures try to minimize the effects but I think the only real concrete data for any given person is form around 300HZ to 3-4000Hz the rest could vary form fixture to fixture and person to person but once you have a trusted source of data and tried some sets you can extrapolate (within reason) .

*Ever noticed how is always the most expensive sets the ones that are more lush, mature, sophisticated, detailed, intricate or have the most 3 dimensional, airy or "orbital" sound, my question is how they put this things in there if they can't be measured not even for reference or to make sure that the whole production have it, how they communicate to their engineers what they want and how do they know is there once the product is finished? And how the engineers know what and how to do?

The headphone/IEM market reminds me of the old days of audiophilia before measurements were widespread and understood.

 

[herr.jemine]

The headphone/IEM market reminds me of the old days of audiophilia before measurements were widespread and understood.

I have definitely noticed that there is a group of people who can perceive a sound stage with IEMs and a group who think they can't hear a sound stage and only hear it close up in their head. You're right, the whole system of ear canal and driver and tip plays a role. I think it's about reflections in the ear canal and possibly in the IEM body, which create a kind of sound stage. For anatomical reasons, this may only be possible for some people in the outer ear canal and they cannot perceive a sound stage with IEMs.