Fiio K13 R2R - Owners Thread

[voodooless]

I could hear distortion from 0.006-0.008 when I actually focused on it. My wife did even better, especially after listening to the entire video.

Pure tones are much easier. With music there is a lot of masking. Try again, this time double blind like the Kippel test.

 

[MAB]

AI is not very accurate for facts like that. The thing is that AI is not "intelligent" at all in the sense of logic. It only "knows" what it was told.

I did this one last time:

I could hear distortion from 0.006-0.008 when I actually focused on it. My wife did even better, especially after listening to the entire video.

I will check out this other link maybe tonight, if not tomorrow.

The thing is that when you listen to music without any reference of how it SHOULD sound; it is easy for distortion to blend into the music while hitting much higher zones.
However the argument of if it can be HEARD vs whether or not you NOTICE it are two completely separate things. You can get away with quite a bit of distortion before its "noticed" hence why people like HiFi / Audiophile stuff after listening to it; because you "unlock" new clearer audio reproduction that you have never heard before. Just like how you can argue that 480i was totally fine for watching videos; anyone who is 35+ watched it for atleast a decade (in the USA)... and if you have never watched 4K high Bitrate; you might say its "completely fine" and that you "don't even notice" the lower bitrate or lower resolution and while that is "true" it doesn't mean its accurate.

Also, for reference, please study actual A/B/X testing. A bit ago you said to me:

The problem I have seen with most ABX testing is that it is done in a very informal way. In music distortion can hide easily, and you have to know what to listen to in a track. Otherwise you could gloss completely over all distortion upto 1%+ THD in some scenarios.
This is why it is important to have something that measures well as a "baseline" and then you can try to hear the differences in the inferior product.
When listening for things to "be better" in a better performing product, you have to listen to the peaks at the higher frequencies which are the most likely to have distortion.
Since even a product with low SINAD should generally perform well in lower frequencies, unless it is an Amp with a poor current delivery topology.... which I believe was the case with most class D amps from some years ago.

When people just "listen to music" and try to hear differences without separating the sounds in the music; they start hallucinating and coming up with all sorts of words to describe what the are hearing.... most of which is just nonsense because your audio memory isn't long enough to be able to put together a thought like that.
The other thing is that most of the time you read about ABX testing; they don't play a specific segment of a song over and over again to try to listen for differences.... just "music" is played and people are asked to guess.
When telling differences in real audio performance; you should only listen to 30 seconds at max and try to choose 7-14 seconds out of that to try to evaluate if you THINK you hear a difference. Then Narrow it down to 7 actual seconds and then 5 or so seconds so you can try to determine if there is a difference. Sometimes you will find that there is no difference even if you THOUGHT you heard one. This is why it is important to have a methodology for testing.... most people buy new gear and just replace their old gear while never doing an ABX test at all... some never do any test at all.... some do crazy sighted bias tests and swear their "new gear" sounds great.... others buy poor quality products and then say that "you have to burn it in for 80 hours".... that process is to train your mind to listen to the worse quality audio, because it won't do anything for the electronics.

The thing is, you got the application of A/B/X testing completely wrong. It is always done with short sections: our auditory memory is only a few seconds. The opposite of what you claim. And certainly the opposite of the video you just tried to show as evidence. You show a track of a continuous sweep of distortion to try to prove a point that goes against decades of scientific study on human thresholds. So, please study the science of how to conduct a proper trial.

And also you keep saying over and over "we need to know the music" blah blah blah. You have no idea what people know outside of reproducible evidence, otherwise just an appeal to authority. I'm still not exactly sure what you mean by having something that measures "baseline". Do you mean a good HiFi? Yeah, mine is OK.

 

[Reynaldo]

In my opinion, this video was more of an attempt to sell more expensive DACs.

Probably after the K13 came out, many much more expensive R2R DAC brands stopped selling their equipment.

 

[SoySalsaPicante]

In my opinion, this video was more of an attempt to sell more expensive DACs.

Probably after the K13 came out, many much more expensive R2R DAC brands stopped selling their equipment.

To be fair, more expensive R-2R DACs can perform much better objectively. Topping Centaurus achieves over 100 SINAD.

 

[xlinknz]

I'm happy with my K13 R2R, SINAD was not a significant factor when buying tbh I was more interested in the headphone capability, aesthetics and functions. I think its good value for the US$232 I paid.

NB: my vintage pre amp which has no digital inputs and a noise spec of -90dB IHF A weighted

 

[Jimster480]

Also, for reference, please study actual A/B/X testing. A bit ago you said to me:


The thing is, you got the application of A/B/X testing completely wrong. It is always done with short sections: our auditory memory is only a few seconds. The opposite of what you claim. And certainly the opposite of the video you just tried to show as evidence. You show a track of a continuous sweep of distortion to try to prove a point that goes against decades of scientific study on human thresholds. So, please study the science of how to conduct a proper trial.

And also you keep saying over and over "we need to know the music" blah blah blah. You have no idea what people know outside of reproducible evidence, otherwise just an appeal to authority. I'm still not exactly sure what you mean by having something that measures "baseline". Do you mean a good HiFi? Yeah, mine is OK.

I understand that it is a complex topic for most to wrap their heads around. Yet seems you still don't understand how I do testing despite quoting one of my other posts, or maybe you didn't read the post you quoted. I understand that complex topics that require thinking and effort... unfortunately not many are willing to put in the time or effort required.

For the video; I did it with my eyes closed and I paused the video or had someone else pause the video after I heard what I was sure was distortion. Each of the different sounds it was different in terms of where the distortion was heard. I already talked about this in my other posts in the other thread last year...

Honestly the "decades of scientific study" is now about 50 years old; lets be real here. When it comes to published studies that most people reference; many were done around the time of the creation of redbook.... on hardware so trash that their best performing devices were worse performing than what you can get from a good phone's 3.5mm jack today...
While you don't have audio "memory" to compare exactly what changed past 7 seconds; you do have an "audio memory" when you understand how good or clean something sounded in a general aspect. Meaning that people wouldn't go in a room with $50 speakers or $5 earbuds and think they sound the same as a $250-5000 competent pair of headphones/speakers.
The difference is that you wouldn't typically know EXACTLY what has changed over time, which is part of the audio memory research that has been done.
Instead what you and a few others are preaching is that you as a human just have no idea about anything; which begs the question of why you are even on this forum? If nobody can tell the difference between $5 headphones and $5000 ones, then why waste $5000? You would have to be clinically retarded or insanely rich to just spend money for no reason or benefit at all right?
Literally insane arguments like the ones being made here are the reason why "subjectivists" dismiss entire communities like this one; because the stance is so beyond insane that nobody with any cognitive function would consider it to be accurate or real. When saying "we trust in the science" and "the science says nobody can hear the difference in audio devices unless they are terrible" you just get instantly written off (and you should).

There are lots of scientific ways to test audio equipment without using fancy devices and only using your ears; but it requires you to not be subjective, train your ears (specifically on various music tracks with different characteristics and ideally high dynamic range, learn to focus, and have someone else help you with switching or create a blind scenario for yourself to remove any other bias. It is hard for many people to be objective and as such this isn't something for everyone, but if you are willing to put in the time and train yourself then I believe that most people (especially young people who haven't blown out their ears with insanely loud music) should be able to do this testing. As time goes on our hearing is not as acute as it was when we were younger....


I did some testing on the website that you guys asked. I'm not sure what settings to pick though, but I tried the 6 inch speaker with the dual tone and another one with a single tone.
On the first test I got - 21, Funnily enough, I got the first question wrong at 12 dB, because the website does not give you an example of what the sound is supposed to sound like. So I thought that the distorted one was the clean one, and that the other one was being given some kind of distortion that was eliminating the details of the sound.
This website also has very poor audio quality itself for example in order to do the test I had to turn my amp on to gain stage 2 and my volume knob to 75 to 85% which is a huge amount of volume way louder than I would ever listen to any music at and the tone was still not to where it was discomfortingly loud.

So the low tone frequency plus the single type of distortion plus the low reference volume are all recipes to mask distortion. So it's no wonder why people can't hear the distortion that far down on this website.

I'll write more about this site in the future, now that I have spent some time on it.

 

[danadam]

Funnily enough, I got the first question wrong at 12 dB, because the website does not give you an example of what the sound is supposed to sound like. So I thought that the distorted one was the clean one, and that the other one was being given some kind of distortion that was eliminating the details of the sound.

I once read someone's comparison of two setups. They described that 1 kHz was "muffled" on one of the two and that's why they didn't like it. Later it turned out that this "muffled" setup was the one that didn't clip

This website also has very poor audio quality itself for example in order to do the test I had to turn my amp on to gain stage 2 and my volume knob to 75 to 85% which is a huge amount of volume way louder than I would ever listen to any music at and the tone was still not to where it was discomfortingly loud.

The two-tone signal is 90 and 800 Hz, both at -14 dBFS. Together that's about -8 dBFS peak. As far as pure tones go, that's quite loud, at least to me.

 

[Jimster480]

I once read someone's comparison of two setups. They described that 1 kHz was "muffled" on one of the two and that's why they didn't like it. Later it turned out that this "muffled" setup was the one that didn't clip


The two-tone signal is 90 and 800 Hz, both at -14 dBFS. Together that's about -8 dBFS peak. As far as pure tones go, that's quite loud, at least to me.
View attachment 538233

When I mentioned that it is quiet, I mean I almost deafened myself with the sound of a discord notification coming through the same audio device while I was doing the test because I had to have the volume up so high in order to have good volume on the testing material.
I've never turned my amplifiers up that high before, as the volume is not at all comfortable with any music that I play. So it's just interesting to me that a website that's supposed to help people to understand and hear distortion or test to see how low of distortion you can hear starts with intentionally quiet tones that would require you to turn your volume up so high.

However, as I mentioned before, from my own personal experiences here, it is obvious that distortion is easier to hear when it is higher frequency or higher amplitude. So, when you are looking at what is lowering the overall SINAD, if it is distortion, and if so, which harmonic distortion is it, or is it a type of hum, from mains leakage or something.

So when I reference amplitude, that's obviously involving volume. So you would be able to hear distortion better the higher the volume. So if the test signal is lower volume, it would be much harder to hear the distortion as you would need a much higher amplification in order to reach the same effective peaks.

This is why I personally believe that the linearity test when it comes to testing things like DAX are the most important because that's showing error versus the input signal. And error, to me, is the easiest to hear in different kinds of music, especially if you listen to higher dynamic range music such as EDM or even modern day while recorded classical.

A violinvs practical limit is 2637 Hz, where the highest note is 3520 Hz, and artificial harmonics combining make 4698 Hz.
My wife plays violin and a bit of piano, so having clear audio reproduction that sounds like the original instrument is important. And it's also where I noticed the most issues in my own testing. Violin especially with its ability to make high frequency note that are long seems to highlight flaws especially when well recorded. The same is the case with flute (which my wife's best friend plays).

 

[RandomEar]

This is why I personally believe that the linearity test when it comes to testing things like DAX are the most important because that's showing error versus the input signal. And error, to me, is the easiest to hear in different kinds of music, especially if you listen to higher dynamic range music such as EDM or even modern day while recorded classical.

Linearity tests in modern DACs almost always show the device running into the noise floor, causing linearity to deviate somewhere below -100 dB. I can't remember the last time the results from this test showed any surprise if you already knew the noise level from a previous test. It's useful to check it, but it will not tell you anything about the "sound" of the device. Even the most broken designs I could find show a linearity which is sufficient for CD audio / Red Book material [1, 2].

 

[Jimster480]

Linearity tests in modern DACs almost always show the device running into the noise floor, causing linearity to deviate somewhere below -100 dB. I can't remember the last time the results from this test showed any surprise if you already knew the noise level from a previous test. It's useful to check it, but it will not tell you anything about the "sound" of the device. Even the most broken designs I could find show a linearity which is sufficient for CD audio / Red Book material [1, 2].

That depends. Not all of them are perfect. In fact, some of the new more modern ones have actually had worse results than ones like my D70S, which is essentially ruler flat.
However, I think that it's more than just what the linearity test measures, but instead what the test represents is that there is flaws in the reproduction. And as such, those flaws can come out possibly in other ways we haven't measured.

However, since we started doing measurements over here, and the website grew large and influential; Most of the DACs that are available today are very competent, and users can literally buy a $100 DAC that provides state-of-the-art performance, which is not something that you could say 10 years ago, and that's a testament to the great work that has been done here, especially by Amir, who has bankrolled this in a sense of having a $28,000 analyzer , and actually spending his time to do this testing.

However, since many of the devices today have managed to hit the peak on the dashboard, I would like to explore new testing that could further separate the different products. I can't expect that from Amir though who is already donating his time here and is very backed up on doing testing in its current form as he has literally months of work at any moment in time.

 

[MAB]

I understand that it is a complex topic for most to wrap their heads around. Yet seems you still don't understand how I do testing despite quoting one of my other posts, or maybe you didn't read the post you quoted. I understand that complex topics that require thinking and effort... unfortunately not many are willing to put in the time or effort required.

For the video; I did it with my eyes closed and I paused the video or had someone else pause the video after I heard what I was sure was distortion. Each of the different sounds it was different in terms of where the distortion was heard. I already talked about this in my other posts in the other thread last year...

Honestly the "decades of scientific study" is now about 50 years old; lets be real here. When it comes to published studies that most people reference; many were done around the time of the creation of redbook.... on hardware so trash that their best performing devices were worse performing than what you can get from a good phone's 3.5mm jack today...
While you don't have audio "memory" to compare exactly what changed past 7 seconds; you do have an "audio memory" when you understand how good or clean something sounded in a general aspect. Meaning that people wouldn't go in a room with $50 speakers or $5 earbuds and think they sound the same as a $250-5000 competent pair of headphones/speakers.
The difference is that you wouldn't typically know EXACTLY what has changed over time, which is part of the audio memory research that has been done.
Instead what you and a few others are preaching is that you as a human just have no idea about anything; which begs the question of why you are even on this forum? If nobody can tell the difference between $5 headphones and $5000 ones, then why waste $5000? You would have to be clinically retarded or insanely rich to just spend money for no reason or benefit at all right?
Literally insane arguments like the ones being made here are the reason why "subjectivists" dismiss entire communities like this one; because the stance is so beyond insane that nobody with any cognitive function would consider it to be accurate or real. When saying "we trust in the science" and "the science says nobody can hear the difference in audio devices unless they are terrible" you just get instantly written off (and you should).

There are lots of scientific ways to test audio equipment without using fancy devices and only using your ears; but it requires you to not be subjective, train your ears (specifically on various music tracks with different characteristics and ideally high dynamic range, learn to focus, and have someone else help you with switching or create a blind scenario for yourself to remove any other bias. It is hard for many people to be objective and as such this isn't something for everyone, but if you are willing to put in the time and train yourself then I believe that most people (especially young people who haven't blown out their ears with insanely loud music) should be able to do this testing. As time goes on our hearing is not as acute as it was when we were younger....


I did some testing on the website that you guys asked. I'm not sure what settings to pick though, but I tried the 6 inch speaker with the dual tone and another one with a single tone.
On the first test I got - 21, Funnily enough, I got the first question wrong at 12 dB, because the website does not give you an example of what the sound is supposed to sound like. So I thought that the distorted one was the clean one, and that the other one was being given some kind of distortion that was eliminating the details of the sound.
This website also has very poor audio quality itself for example in order to do the test I had to turn my amp on to gain stage 2 and my volume knob to 75 to 85% which is a huge amount of volume way louder than I would ever listen to any music at and the tone was still not to where it was discomfortingly loud.

So the low tone frequency plus the single type of distortion plus the low reference volume are all recipes to mask distortion. So it's no wonder why people can't hear the distortion that far down on this website.

I'll write more about this site in the future, now that I have spent some time on it.

Don't worry about me wrapping my head around it.

Regarding science that was done 50 years ago, it's still as relevant today as it was ages ago unless someone has new observations that contradict.

With nthat in mind, you provided another contemporary data point. You heard -21dB in an actual controlled blind test, that's 8.9% distortion. With some practice, you can likely do a bit better, but not much, you are human. The video with the ramping distortion is in no way a blind test, nor could it be used as the basis for a blind test of distortion threshold. I explained already, but not going to belabor the point to you. I will point out that "poor audio quality" and -14 dBFS are two different things. -14 dBFS is a safety feature, it would be irresponsible to put pure tones recorded near max volume in a test like this for people to blow speakers and ears. Turn up the volume as you see fit. Also, Klippel gives you an example and the test is a comparison test. If you can't hear it in comparison, you can't hear it. It's not about familiarity, it's about threshold. I recommend reading Klippel's documentation. I bet you can get over -30 dB.

Like I said, humbling if you actually take a real test. Testing your hearing's frequency response is another humbling thing.

You should go to an audiologist and take a hearing test if you really want to know about the limits of your ears. Run by the doctor that you think you can hear things at -100 dB. They might also give you some insight as to why -21 dB isn't rally that bad at all.

 

[Jimster480]

Don't worry about me wrapping my head around it.

Regarding science that was done 50 years ago, it's still as relevant today as it was ages ago unless someone has new observations that contradict.

With nthat in mind, you provided another contemporary data point. You heard -21dB in an actual controlled blind test, that's 8.9% distortion. With some practice, you can likely do a bit better, but not much, you are human. The video with the ramping distortion is in no way a blind test, nor could it be used as the basis for a blind test of distortion threshold. I explained already, but not going to belabor the point to you. I will point out that "poor audio quality" and -14 dBFS are two different things. -14 dBFS is a safety feature, it would be irresponsible to put pure tones recorded near max volume in a test like this for people to blow speakers and ears. Turn up the volume as you see fit. Also, Klippel gives you an example and the test is a comparison test. If you can't hear it in comparison, you can't hear it. It's not about familiarity, it's about threshold. I recommend reading Klippel's documentation. I bet you can get over -30 dB.

Like I said, humbling if you actually take a real test. Testing your hearing's frequency response is another humbling thing.

You should go to an audiologist and take a hearing test if you really want to know about the limits of your ears. Run by the doctor that you think you can hear things at -100 dB. They might also give you some insight as to why -21 dB isn't rally that bad at all.

I did -36 and -41 (2nd try) on the 800 80 hz tone test after a break from the first test. (6 in speaker)
I went back and did the first test (terz) with a bit higher volume on my amp; I got -27. After that I had a headache from these horrible sounds, and secondary notification sounds almost deafening me due to the -14dbfs reference (requiring my amp volume to be sky high).
One day if I have time to shut down everything and just sit in a quiet room to do this test (my workstation fan sounds are heard through my headphones) with the volume higher (and no other applications playing into my audio device); I will actually try to see how low I can hear distortion on all the different tests.

The website is overall TERRIBLE and made to be done multiple times so you can familiarize yourself and try to learn to hear the distortion itself. This isn't really the spirit of listening in the first place. The audio quality on the website is trash, and depending on what you listen to distortion is much easier to hear; it also depends on what kind of distortion. The website provides none of that and therefore is just a fun "game" for people to try to see how low they can "score".
Despite -14dbfs or not; the "music" samples on the website also sound like trash; likely meaning that they are using low bit rate tones in the first place.

I understand why you don't consider the video to be blind because the distortion is forever increasing; so even if you have someone else stop and start the video and move around the markers... it is still not totally "blind".

 

[MAB]

I did -36 and -41 (2nd try) on the 800 80 hz tone test after a break from the first test. (6 in speaker)
I went back and did the first test (terz) with a bit higher volume on my amp; I got -27. After that I had a headache from these horrible sounds, and secondary notification sounds almost deafening me due to the -14dbfs reference (requiring my amp volume to be sky high).
One day if I have time to shut down everything and just sit in a quiet room to do this test (my workstation fan sounds are heard through my headphones) with the volume higher (and no other applications playing into my audio device); I will actually try to see how low I can hear distortion on all the different tests.

The website is overall TERRIBLE and made to be done multiple times so you can familiarize yourself and try to learn to hear the distortion itself. This isn't really the spirit of listening in the first place. The audio quality on the website is trash, and depending on what you listen to distortion is much easier to hear; it also depends on what kind of distortion. The website provides none of that and therefore is just a fun "game" for people to try to see how low they can "score".
Despite -14dbfs or not; the "music" samples on the website also sound like trash; likely meaning that they are using low bit rate tones in the first place.

I understand why you don't consider the video to be blind because the distortion is forever increasing; so even if you have someone else stop and start the video and move around the markers... it is still not totally "blind".

It helps in a quiet room. Good grief though, don't play it so loud you cause your ears to ring. I'm not sure what your struggle is, but cranking up test tones is really odd way to prove to yourself the limits of your hearing.

The samples are not as you say "low bit rate." The YouTube video you used earlier as demonstration is certainly not CD quality, but in reality the bit depth or sample rate of the playback of the Klippel test or the video demo you posted isn't the problem. The sound quality of the undistorted signals Klippel presents is fine.

The website provides answers to all of your questions, and in fact the test is quite a good one if you are interested in what humans (meaning you) can actually hear. So I won't add anything since they have a nice section with excellent explanations.

One thing for sure, testing your hearing ability isn't really fun. Less so when you find out that you can't hear like you thought. Like I said at the outset, humbling for many. It's also not fun talking endlessly about things that have been known for decades. I've said enough to you.

 

[Jimster480]

It helps in a quiet room. Good grief though, don't play it so loud you cause your ears to ring. I'm not sure what your struggle is, but cranking up test tones is really odd way to prove to yourself the limits of your hearing.

The samples are not as you say "low bit rate." The YouTube video you used earlier as demonstration is certainly not CD quality, but in reality the bit depth or sample rate of the playback of the Klippel test or the video demo you posted isn't the problem. The sound quality of the undistorted signals Klippel presents is fine.

The website provides answers to all of your questions, and in fact the test is quite a good one if you are interested in what humans (meaning you) can actually hear. So I won't add anything since they have a nice section with excellent explanations.

One thing for sure, testing your hearing ability isn't really fun. Less so when you find out that you can't hear like you thought. Like I said at the outset, humbling for many. It's also not fun talking endlessly about things that have been known for decades. I've said enough to you.

I didn't crank up the test tone to a deafening volume, I set it to a bit louder than my normal listening volume. Just the reference volume for the actual test is so low; that if other things on my computer make sound (like a discord notification) it is then incredibly loud (since all other sounds aren't at -14dbfs like the testing website).

It is obvious we won't agree here; the Kippel website is trash with low quality tones, the musical clips on there sound worse than any streaming service (even selecting Spotify or Tidal "Low") and the reference of -14dbfs is idiotic.
We can leave it at that; you can believe what you like and I will continue on my journey disproving what others believe to be fact

Have a great day / night!

 

[RexrothPigeon]

I didn't crank up the test tone to a deafening volume, I set it to a bit louder than my normal listening volume. Just the reference volume for the actual test is so low; that if other things on my computer make sound (like a discord notification) it is then incredibly loud (since all other sounds aren't at -14dbfs like the testing website).

I'd just turn off notifications myself, but people do be different

 

[antcollinet]

I will continue on my journey disproving

I will look forward to seeing your proofs.

And there is nothing stopping you from generating your own file based blind tests. @pkane 's distort app can apply any distortion at any level to any file you like. Pick your own favourite music - generate different levels of distortion - then ABX in foobar or similar to see what level you can actually hear. I'm guessing you won't do much better than on the Klippel test.

 

[Jimster480]

I will look forward to seeing your proofs.

And there is nothing stopping you from generating your own file based blind tests. @pkane 's distort app can apply any distortion at any level to any file you like. Pick your own favourite music - generate different levels of distortion - then ABX in foobar or similar to see what level you can actually hear. I'm guessing you won't do much better than on the Klippel test.

Cool, thank you. I will play around with this software. It looks quite interesting. I put it on my list of things to do.

Listening Test

www.klippel.de

According to this graph my result doesn't exist? I got to -41 and yet it shows only - 33 as the top.
Which is the best test on this site? Just by going through the combinations, it looks like I should have chosen the full range speaker tests. Maybe they have better references too, since people obviously have better results there.

 

[vdem]

In my opinion, this video was more of an attempt to sell more expensive DACs.

Probably after the K13 came out, many much more expensive R2R DAC brands stopped selling their equipment.

The Gustard DR70 on AliExpress costs about $230 (sale + coupons, etc.) and offers objectively better measurements, with a SINAD of -87.5 dB.

Spoiler: DR70

It is more than 10 times better based on SINAD. And yes, many more expensive R-2R have better objective measurements. Is it worth paying extra - is another question

 

[antcollinet]

Listening Test

www.klippel.de

According to this graph my result doesn't exist? I got to -41 and yet it shows only - 33 as the top.

As far as I can tell on the Klippel site, the left most bar always shows "that amount and lower (lower distortion), which is why that bar is so tall - it includes all results better than -33. Not sure why they stop at -33 on that one though.

Which is the best test on this site? Just by going through the combinations, it looks like I should have chosen the full range speaker tests. Maybe they have better references too, since people obviously have better results there.

IMO you should choose full range speaker - and music rather than test tones. I personally don't care how low I can hear distortion on a test tone - that is not what I listen to. Nor do I listen to single driver speakers.

 

[xlinknz]

For those that don't already know Fiio plan to compliment the K13 R2R with a K13 Delta Sigma version, ETA November 2026