This is a review and detailed measurements of the 64 Audio U12t IEM. It is on kind loan from a member and costs US $1,999.
Typical of these IEMs, the U12t is a chunky unit. While comfort was fine, it made it challenging at first to measure. Included cord was a bit too short for my taste but I think this is typical of IEMs. And alternate set of "silver" pipes come with the unit. I did not test that and stuck with the gray one you see in the picture.
Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!
64 Audio U12t Measurements
Let's start with our usual dashboard and special target for IEMs:
I was impressed by the almost complete compliance with our target up to about 2 kHz after which we take a dip. There is also drop off post 5 kHz. These will likely cost it spatial qualities. Here is the same but relative to our target curve:
Distortion measurements showed disappointing performance especially at this price point:
Group delay is not very revealing:
Impedance is low and flat:
The kinks in zoomed display though indicate various acoustic events that would have been nice to have been ironed out.
Sensitivity is very good:
64 Audio U12t Listening Tests
The included silicone tip fit me well but later testing with deep bass content showed very little output in that region. I tried to push them in some but could not remedy that. Response without equalization was good but it definitely improved with EQ:
I toned down the filter at 8500 Hz as it made it too bright when set as measurements indicated. Without EQ, I found female vocals to sound somewhat stuffy.
I was very impressed with instrument separation causing many moments of delight. High frequency detail was very good but at times, seemed hyper exaggerated. Not sure if this is due to EQ I applied (was less so without it) or the distortion.
Conclusions
I was pleased to see such high compliance with our target curve but why not go all the way and fill that hole around 3 kHz? Maybe that would have made it sound too bright to some people. For me, it is a failing which when combined with high distortion knocked down the unit a full notch. Note that it is still a good sounding IEM without EQ which I can't say for many designs.
I am going to put the 64 Audio U12t IEM on my recommended list although personally I can't justify its cost.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Typical of these IEMs, the U12t is a chunky unit. While comfort was fine, it made it challenging at first to measure. Included cord was a bit too short for my taste but I think this is typical of IEMs. And alternate set of "silver" pipes come with the unit. I did not test that and stuck with the gray one you see in the picture.
Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!
64 Audio U12t Measurements
Let's start with our usual dashboard and special target for IEMs:
I was impressed by the almost complete compliance with our target up to about 2 kHz after which we take a dip. There is also drop off post 5 kHz. These will likely cost it spatial qualities. Here is the same but relative to our target curve:
Distortion measurements showed disappointing performance especially at this price point:
Group delay is not very revealing:
Impedance is low and flat:
The kinks in zoomed display though indicate various acoustic events that would have been nice to have been ironed out.
Sensitivity is very good:
64 Audio U12t Listening Tests
The included silicone tip fit me well but later testing with deep bass content showed very little output in that region. I tried to push them in some but could not remedy that. Response without equalization was good but it definitely improved with EQ:
I toned down the filter at 8500 Hz as it made it too bright when set as measurements indicated. Without EQ, I found female vocals to sound somewhat stuffy.
I was very impressed with instrument separation causing many moments of delight. High frequency detail was very good but at times, seemed hyper exaggerated. Not sure if this is due to EQ I applied (was less so without it) or the distortion.
Conclusions
I was pleased to see such high compliance with our target curve but why not go all the way and fill that hole around 3 kHz? Maybe that would have made it sound too bright to some people. For me, it is a failing which when combined with high distortion knocked down the unit a full notch. Note that it is still a good sounding IEM without EQ which I can't say for many designs.
I am going to put the 64 Audio U12t IEM on my recommended list although personally I can't justify its cost.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
