[Precogvision]

Hey all, the U18S demo unit arrived today! I haven't gotten to much ear time on it, but here are some first impressions.

Spoiler: FR Graph

First off, they sound very different from the U18T. The U18T is considerably more mid-bass emphasized, upper-midrange forward, and significantly brighter. This culminates in a more in-your-face presentation. The U18S, then, is for people who did not enjoy the U18t and more closely aligned with the U12T’s sound. The U18S is more laid-back, sporting a gentle, U-shaped curve. The tonal balance here is terrific. The only issue I would point out is what appears to be the lack of mid-treble energy; the U18S’s treble can run on the darker side as it dips somewhere after ~8kHz. Like most of the 64 Audio IEMs, though, it comes back up for air at around ~15kHz, so you’re going to get that very airy zing. In general, this is an easy on-the-ears tuning that works terrific with the Apex modules for extended listening.

Technicalities are interesting. Imaging is expectedly excellent thanks to the spike of treble air; I swear those tia tweeters work magic. Detail on the U18S is fantastic too, enough to play near the top. It's noticeably more resolving than the U18T which is surprising given that the U18T is much brighter-leaning. To this end, I have to wonder if the drivers being used in the U18S have changed. The shell is slightly larger in width than the U18T and the other 64 Audio IEMs; the transient behavior of the U18S also sounds different to my ears. Of course, it's very possible that these are more the by-product of tonal shifts, but given the discrepancy between perceived detail and their respective tunings, I think there is some merit to this theory.

And of course, a comparison to the U12T is warranted. Although they sound very close tonally, they don't sound so similar when it comes to transient behavior. The bass on the U12T is more impactful to my ears, so I don't think these are the same drivers being used for the low-end in the U18S. The U12T remains my benchmark for BA bass. Unfortunately, the U18S also sounds noticeably flatter, more downwards-compressed to the way it scales dynamic swings. The U12T is smoother in transient attack and decay; the U18S is more micro detail-oriented, textured to my ears. So on the flip side, for sheer detail, the U18S is easily on par.

For now, I can confidently say that the U18S is solid work by 64 Audio and an apt foil to the A18T. Whether it’s "worth it" when the U12T exists is another matter that’ll have to be explored more closely, but suffice it to say I'd struggle to see a listener being unhappy with either of them. I also heard the U18T today, so with this I've heard the entire 64 Audio lineup!

 

[Tristy]

Hey all, the U18S demo unit arrived today! I haven't gotten to much ear time on it, but here are some first impressions.

Spoiler: FR Graph

First off, they sound very different from the U18T. The U18T is considerably more mid-bass emphasized, upper-midrange forward, and significantly brighter. This culminates in a more in-your-face presentation. The U18S, then, is for people who did not enjoy the U18t and more closely aligned with the U12T’s sound. The U18S is more laid-back, sporting a gentle, U-shaped curve. The tonal balance here is terrific. The only issue I would point out is what appears to be the lack of mid-treble energy; the U18S’s treble can run on the darker side as it dips somewhere after ~8kHz. Like most of the 64 Audio IEMs, though, it comes back up for air at around ~15kHz, so you’re going to get that very airy zing. In general, this is an easy on-the-ears tuning that works terrific with the Apex modules for extended listening.

Technicalities are interesting. Imaging is expectedly excellent thanks to the spike of treble air; I swear those tia tweeters work magic. Detail on the U18S is fantastic too, enough to play near the top. It's noticeably more resolving than the U18T which is surprising given that the U18T is much brighter-leaning. To this end, I have to wonder if the drivers being used in the U18S have changed. The shell is slightly larger in width than the U18T and the other 64 Audio IEMs; the transient behavior of the U18S also sounds different to my ears. Of course, it's very possible that these are more the by-product of tonal shifts, but given the discrepancy between perceived detail and their respective tunings, I think there is some merit to this theory.

And of course, a comparison to the U12T is warranted. Although they sound very close tonally, they don't sound so similar when it comes to transient behavior. The bass on the U12T is more impactful to my ears, so I don't think these are the same drivers being used for the low-end in the U18S. The U12T remains my benchmark for BA bass. Unfortunately, the U18S also sounds noticeably flatter, more downwards-compressed to the way it scales dynamic swings. The U12T is smoother in transient attack and decay; the U18S is more micro detail-oriented, textured to my ears. So on the flip side, for sheer detail, the U18S is easily on par.

For now, I can confidently say that the U18S is solid work by 64 Audio and an apt foil to the A18T. Whether it’s "worth it" when the U12T exists is another matter that’ll have to be explored more closely, but suffice it to say I'd struggle to see a listener being unhappy with either of them. I also heard the U18T today, so with this I've heard the entire 64 Audio lineup!

@Precogvision i don’t suppose you have a graph of the U12t lying about also do you? For comparison purposes...

 

[MatW]

Hey all, the U18S demo unit arrived today! I haven't gotten to much ear time on it, but here are some first impressions.

Spoiler: FR Graph

First off, they sound very different from the U18T. The U18T is considerably more mid-bass emphasized, upper-midrange forward, and significantly brighter. This culminates in a more in-your-face presentation. The U18S, then, is for people who did not enjoy the U18t and more closely aligned with the U12T’s sound. The U18S is more laid-back, sporting a gentle, U-shaped curve. The tonal balance here is terrific. The only issue I would point out is what appears to be the lack of mid-treble energy; the U18S’s treble can run on the darker side as it dips somewhere after ~8kHz. Like most of the 64 Audio IEMs, though, it comes back up for air at around ~15kHz, so you’re going to get that very airy zing. In general, this is an easy on-the-ears tuning that works terrific with the Apex modules for extended listening.

Technicalities are interesting. Imaging is expectedly excellent thanks to the spike of treble air; I swear those tia tweeters work magic. Detail on the U18S is fantastic too, enough to play near the top. It's noticeably more resolving than the U18T which is surprising given that the U18T is much brighter-leaning. To this end, I have to wonder if the drivers being used in the U18S have changed. The shell is slightly larger in width than the U18T and the other 64 Audio IEMs; the transient behavior of the U18S also sounds different to my ears. Of course, it's very possible that these are more the by-product of tonal shifts, but given the discrepancy between perceived detail and their respective tunings, I think there is some merit to this theory.

And of course, a comparison to the U12T is warranted. Although they sound very close tonally, they don't sound so similar when it comes to transient behavior. The bass on the U12T is more impactful to my ears, so I don't think these are the same drivers being used for the low-end in the U18S. The U12T remains my benchmark for BA bass. Unfortunately, the U18S also sounds noticeably flatter, more downwards-compressed to the way it scales dynamic swings. The U12T is smoother in transient attack and decay; the U18S is more micro detail-oriented, textured to my ears. So on the flip side, for sheer detail, the U18S is easily on par.

For now, I can confidently say that the U18S is solid work by 64 Audio and an apt foil to the A18T. Whether it’s "worth it" when the U12T exists is another matter that’ll have to be explored more closely, but suffice it to say I'd struggle to see a listener being unhappy with either of them. I also heard the U18T today, so with this I've heard the entire 64 Audio lineup!

Thanks for these impressions.

One thing I'd like to learn as a reader and viewer of many reviews, is how to interpret references to frequency ranges. E.g. when you mention the 'lack of mid treble energy', I'd like to know which instruments or sounds you are referring to. I have searched for an overview of this, i.e. links between instruments and frequency range, but haven't found anything very useful yet.

 

[Precogvision]

@Precogvision i don’t suppose you have a graph of the U12t lying about also do you? For comparison purposes...

Yup! Here you are:

Spoiler: FR Comparison

These are both with the M15 module and matched at 1kHz. Anecdotally, I would agree that the U18S's pinna compensation leans even more relaxed than the U12T's. You can also see the U12T has more lower-treble energy which is part of why I said the U18S comes off as darker in comparison. I'll have to sine-sweep them to confirm more differences in treble, though, as the resonance peak area is finicky.

Thanks for these impressions.

One thing I'd like to learn as a reader and viewer of many reviews, is how to interpret references to frequency ranges. E.g. when you mention the 'lack of mid treble energy', I'd like to know which instruments or sounds you are referring to. I have searched for an overview of this, i.e. links between instruments and frequency range, but haven't found anything very useful yet.

I'm mostly associating mid-treble with instrument crash. Unfortunately, I don't know the names of all the instruments I hear, and I'm sure someone else can do a better job of explaining it than me! Someone like @Deezel177 comes to mind, his explanations are top-tier.

Anyways, the problem with this stuff - and so much in audio - is just how darn subjective it is. Everyone has their own interpretation of what falls under each frequency range. For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

 

[Tristy]

Yup! Here you are:

Spoiler: FR Comparison

These are both with the M15 module and matched at 1kHz. Anecdotally, I would agree that the U18S's pinna compensation leans even more relaxed than the U12T's. You can also see the U12T has more lower-treble energy which is part of why I said the U18S comes off as darker in comparison. I'll have to sine-sweep them to confirm more differences in treble, though, as the resonance peak area is finicky.



I'm mostly associating mid-treble with instrument crash. Unfortunately, I don't know the names of all the instruments I hear, and I'm sure someone else can do a better job of explaining it than me! Someone like @Deezel177 comes to mind, his explanations are top-tier.

Anyways, the problem with this stuff - and so much in audio - is just how darn subjective it is. Everyone has their own interpretation of what falls under each frequency range. For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

Great, thank you!

 

[MatW]

Yup! Here you are:

Spoiler: FR Comparison

These are both with the M15 module and matched at 1kHz. Anecdotally, I would agree that the U18S's pinna compensation leans even more relaxed than the U12T's. You can also see the U12T has more lower-treble energy which is part of why I said the U18S comes off as darker in comparison. I'll have to sine-sweep them to confirm more differences in treble, though, as the resonance peak area is finicky.



I'm mostly associating mid-treble with instrument crash. Unfortunately, I don't know the names of all the instruments I hear, and I'm sure someone else can do a better job of explaining it than me! Someone like @Deezel177 comes to mind, his explanations are top-tier.

Anyways, the problem with this stuff - and so much in audio - is just how darn subjective it is. Everyone has their own interpretation of what falls under each frequency range. For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

Thank you.

I found a similar overview but indeed the amount of overlap makes it difficult to use. I love when reviewers include references to songs and how they hear them, to explain their point of view, because then I can go listen to the song and experience it myself.

 

[gnahra]

Yup! Here you are:

Spoiler: FR Comparison

These are both with the M15 module and matched at 1kHz. Anecdotally, I would agree that the U18S's pinna compensation leans even more relaxed than the U12T's. You can also see the U12T has more lower-treble energy which is part of why I said the U18S comes off as darker in comparison. I'll have to sine-sweep them to confirm more differences in treble, though, as the resonance peak area is finicky.



I'm mostly associating mid-treble with instrument crash. Unfortunately, I don't know the names of all the instruments I hear, and I'm sure someone else can do a better job of explaining it than me! Someone like @Deezel177 comes to mind, his explanations are top-tier.

Anyways, the problem with this stuff - and so much in audio - is just how darn subjective it is. Everyone has their own interpretation of what falls under each frequency range. For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

@Precogvision thanks for this - really appreciate it.
Any chance you're willing/able to share a comparison chart of the U12t/U18s with the m20 module?

 

[kdl0123]

Yup! Here you are:

Spoiler: FR Comparison

These are both with the M15 module and matched at 1kHz. Anecdotally, I would agree that the U18S's pinna compensation leans even more relaxed than the U12T's. You can also see the U12T has more lower-treble energy which is part of why I said the U18S comes off as darker in comparison. I'll have to sine-sweep them to confirm more differences in treble, though, as the resonance peak area is finicky.



I'm mostly associating mid-treble with instrument crash. Unfortunately, I don't know the names of all the instruments I hear, and I'm sure someone else can do a better job of explaining it than me! Someone like @Deezel177 comes to mind, his explanations are top-tier.

Anyways, the problem with this stuff - and so much in audio - is just how darn subjective it is. Everyone has their own interpretation of what falls under each frequency range. For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

It seems U18s is much closer to the A18s custom in fr. The A18s demo that used before looks different.

 

[DavidS11]

Do you use 64Audio's vac? I have that and I find it completely useless. No suction at all. Not worth sending it back to them due to costs back and forth to the UK. Not a happy bunny with this vac

I have no problem with the suction of my 64 Audio IEM Vac. The suction is not super strong but it gets the job done. You don’t want too strong suction else it could pull out the mesh.

Make sure the tubing is properly connected and there is no leakage. Check the o-ring at the bottom of syringe. Mine was broken and I had to replace it.

 

[Deezel177]

Thanks for these impressions.

One thing I'd like to learn as a reader and viewer of many reviews, is how to interpret references to frequency ranges. E.g. when you mention the 'lack of mid treble energy', I'd like to know which instruments or sounds you are referring to. I have searched for an overview of this, i.e. links between instruments and frequency range, but haven't found anything very useful yet.

When it comes to the mid-treble, I'd agree with @Precogvision that it relates to an instrument's crash. More specifically, I'd describe it as a cymbal's brash-ness. If you were to dip that region, you'd hear a tshhh..., rather than a tsss... on crash cymbals, as I described with the Snarky Puppy track on my review. You'd also tend to hear less of a lisp with vocals. Whereas, if you were to dip the low-treble (around 5kHz), you'd hear a phhh..., rather than a tsss... So, dipping the low-treble takes away the t or the tick plosive, while dipping the mid-treble takes the abrasiveness of the s away. That's how I tend to hear it, anyway, As @Precogvision said, there'll be subjectiveness that plays into it too.

Yup! Here you are:

Spoiler: FR Comparison

These are both with the M15 module and matched at 1kHz. Anecdotally, I would agree that the U18S's pinna compensation leans even more relaxed than the U12T's. You can also see the U12T has more lower-treble energy which is part of why I said the U18S comes off as darker in comparison. I'll have to sine-sweep them to confirm more differences in treble, though, as the resonance peak area is finicky.



I'm mostly associating mid-treble with instrument crash. Unfortunately, I don't know the names of all the instruments I hear, and I'm sure someone else can do a better job of explaining it than me! Someone like @Deezel177 comes to mind, his explanations are top-tier.

Anyways, the problem with this stuff - and so much in audio - is just how darn subjective it is. Everyone has their own interpretation of what falls under each frequency range. For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

Thanks for your kind words. I really like that graphic. Of all the graphics I've seen with regards to frequency response, that's probably the one that aligns best with my own definitions. Though, I'd probably say the midrange starts higher up at 300Hz, and 5kHz would already be the low-treble.

When it comes to engineers having different definitions for bass, midrange, treble and everything in between, I've found that they'll largely adapt it according to the instrument in question. My college lecturer, for example, used to give the kick drum a "bass" of 20-60Hz, a "midrange" of 100-1kHz and a "treble" of 2-4kHz; approximately. That'd be different for the electric guitar, for vocals, etc. With electric guitars, you could even extend those differences in definition to amp manufacturers like Marshall, who install Bass, Midrange and Treble dials to their amps that don't align in any way whatsoever to the graphic above. So, yeah, it's important to note that the definitions of bass, midrange and treble we talk about here are ones that we've adopted from speaker designers and hi-fi enthusiasts, rather than musicians or engineers, especially when they localise or adapt their definitions to their instrument of choice. That's not to say those definitions are any less valid. They just happen to not align with what we talk about here.

 

[gLer]

For example, I recently learned that audio engineers consider the upper-midrange to fall under 2kHz, whereas I'd say it goes up to around 4kHz. The latter is more colloquially accepted, but the reality is that much of the female vocal fundamentals are under 2kHz. When you listen to a sine-sweep at 3-4kHz, you don't think midrange; it's much higher-pitched than that. So really, it's just female vocal upper-harmonics that extend into 4kHz and beyond. You can use this excellent chart for a quick reference, but again, there's lots of overlap and it's pending your own interpretation.

Yes, this! I recently had the same epiphany when reading an article about FR. I always thought upper mids stretched to 5khz, but apparently no, they range between 2-4khz. Which means I've been slightly misinterpreting FR graphs for forever! Who would've thought 5khz was regarded as treble, but there you go.

I have no problem with the suction of my 64 Audio IEM Vac. The suction is not super strong but it gets the job done. You don’t want too strong suction else it could pull out the mesh.

Make sure the tubing is properly connected and there is no leakage. Check the o-ring at the bottom of syringe. Mine was broken and I had to replace it.

I'm getting my first VAC on Monday, touch wood. So excited! After the debacle of my Fourte mesh coming off from a gentle clean, I couldn't any more. It's time to clean IEMs properly. These are not toys. There's a long story behind this too, which I'll share once it's all here.

When it comes to the mid-treble, I'd agree with @Precogvision that it relates to an instrument's crash. More specifically, I'd describe it as a cymbal's brash-ness. If you were to dip that region, you'd hear a tshhh..., rather than a tsss... on crash cymbals, as I described with the Snarky Puppy track on my review. You'd also tend to hear less of a lisp with vocals. Whereas, if you were to dip the low-treble (around 5kHz), you'd hear a phhh..., rather than a tsss... So, dipping the low-treble takes away the t or the tick plosive, while dipping the mid-treble takes the abrasiveness of the s away. That's how I tend to hear it, anyway, As @Precogvision said, there'll be subjectiveness that plays into it too.

That makes so much sense! It explains why EQing 6khz down to remove the sssssibilance doesn't work! It was 4khz all along. Dang. And yet read most reviews and they'll complain about 6khz and 8khz peaks affecting sibilance. Not so. Time to get more educated on my part. This hobby never ceases to amaze.

 

[DavidS11]

I'm getting my first VAC on Monday, touch wood. So excited! After the debacle of my Fourte mesh coming off from a gentle clean, I couldn't any more. It's time to clean IEMs properly. These are not toys. There's a long story behind this too, which I'll share once it's all here.

It’s a good tool to have, especially since we have invested so much in multiple expensive IEMs. It’s not cheap (after all it’s just a mini Vac) but worth it in the long run.

Hope you will get back your beloved Fourte too in great condition again

 

[CL14715]

When it comes to the mid-treble, I'd agree with @Precogvision that it relates to an instrument's crash. More specifically, I'd describe it as a cymbal's brash-ness. If you were to dip that region, you'd hear a tshhh..., rather than a tsss... on crash cymbals, as I described with the Snarky Puppy track on my review. You'd also tend to hear less of a lisp with vocals. Whereas, if you were to dip the low-treble (around 5kHz), you'd hear a phhh..., rather than a tsss... So, dipping the low-treble takes away the t or the tick plosive, while dipping the mid-treble takes the abrasiveness of the s away. That's how I tend to hear it, anyway, As @Precogvision said, there'll be subjectiveness that plays into it too.


Thanks for your kind words. I really like that graphic. Of all the graphics I've seen with regards to frequency response, that's probably the one that aligns best with my own definitions. Though, I'd probably say the midrange starts higher up at 300Hz, and 5kHz would already be the low-treble.

When it comes to engineers having different definitions for bass, midrange, treble and everything in between, I've found that they'll largely adapt it according to the instrument in question. My college lecturer, for example, used to give the kick drum a "bass" of 20-60Hz, a "midrange" of 100-1kHz and a "treble" of 2-4kHz; approximately. That'd be different for the electric guitar, for vocals, etc. With electric guitars, you could even extend those differences in definition to amp manufacturers like Marshall, who install Bass, Midrange and Treble dials to their amps that don't align in any way whatsoever to the graphic above. So, yeah, it's important to note that the definitions of bass, midrange and treble we talk about here are ones that we've adopted from speaker designers and hi-fi enthusiasts, rather than musicians or engineers, especially when they localise or adapt their definitions to their instrument of choice. That's not to say those definitions are any less valid. They just happen to not align with what we talk about here.

Funny this is being explained and of all places 64 Audio’s thread. I’ve always wondered what their very intentional appearing 1k suck out changed sound wise. It’s seen on the Trio, Fourte and Noir but those are arguably their best sounding universals. I’ve almost arrived at the conclusion that 1k doesn’t do anything so they pull it out to create headroom and spaciousness entering mids. But if you look at the sounds utilizing 1k it doesn’t make sense.

 

[CL14715]

That makes so much sense! It explains why EQing 6khz down to remove the sssssibilance doesn't work! It was 4khz all along. Dang. And yet read most reviews and they'll complain about 6khz and 8khz peaks affecting sibilance. Not so. Time to get more educated on my part. This hobby never ceases to amaze.

Lol yep, buuuuut peaky 8k will add air and shimmer to a sibilant 4k hit.

 

[Deezel177]

Funny this is being explained and of all places 64 Audio’s thread. I’ve always wondered what their very intentional appearing 1k suck out changed sound wise. It’s seen on the Trio, Fourte and Noir but those are arguably their best sounding universals. I’ve almost arrived at the conclusion that 1k doesn’t do anything so they pull it out to create headroom and spaciousness entering mids. But if you look at the sounds utilizing 1k it doesn’t make sense.

I criticised that 1kHz dip on my Noir review. That region, most especially when followed by a rise towards 2kHz, is crucial for an instrument's structure; its density, solidity and tactility. A snare drum without presence at 1-2kHz tends to come off light and clang-y; missing thud. And, vocals will sound like they're coming solely from the singer's mouth without much support coming from the diaphragm or chest. But, as I've expressed on another thread in the past, the midrange is also the region where colour tends to be more permitted. Based on conversations I've seen and had on- and offline, I've found that you can push and pull on it quite a bit before it becomes palpably unnatural or odd-sounding. Combined with the fact that 64's 1kHz dips tend to be tastefully-done anyway, and you have yourself a colouration that becomes very easily accepted.