This is a review and detailed measurements of the AKG K371 closed-back headphone. I purchased this last summer and it currently costs US $149 on Amazon including shipping.
Note: our company, Madrona Digital, carries various Harman brand products although not the AKG products.
The K371 is made out of plastic but has a nice finish which belies its cheap structure:
I especially like the feel of the pads. They are not huge but big enough to fit around my ears. Inside height of the pad is 2.51 inches. Inside width is 1.62 inches. With no depression, the pad depth to the driver is 0.8 inches. Outside diameter of the pad is 4 inches by 3 inches.
Three different cords are supplied which terminate into a 3-pin mini-XLR:
Let me warn you about something I hate about these headphones: the headband adjustment mechanism. It either gets stuck and doesn't move at all. Or all of a sudden moves a bunch of notches. I also see reports of the mechanism failing which means you have to send them back to Harman/AKG for repair (you pay shipping even under warranty).
Clamp pressure is a bit much especially if you wear glasses at first but gets better with some use. When I take them off, the pads are quite warm so likely in summer, they will not be comfortable if your room is not cool.
Note 1: The measurements you are about to see are preformed using standardized GRAS 45CA headphone measurement fixture. Headphone measurements require more interpretation than speaker tests and have more of a requirement for subjective testing as a result. In addition, comparison of measurements between different people doing it using different configurations requires fair bit of skill. So don't look for matching results. Focus on high level picture.
Getting the K371 seated did not require much work and indeed, measurements track some of the others I have seen using same fixture as I use.
AKG K371 Measurements
As usual we start with frequency response of K371. They are said to follow the Harman target. Let's see if that is the case:
This looks to be closest we have gotten to the target. Indeed in sub-bass where vast majority of headphones fall off, the K371 actually overachieves a bit. Then again the Harman fixture is a bit different than what the rest of us use so maybe in their fixture that was right on the money. Either way, during equalization and listening tests we will investigate this further.
Following down the curve, we have a dip around 3.8 to 3.9 kHz. It is a shame as past that the response envelop more or less follows our target.
We can subtract the response from the target and see the deviations:
Distortion is better than average:
The 94 dB line in blue shows extremely good performance. That keeps up even at 104 dBSPL.
Edit: forgot to include the absolute measurements:
Group delay gives us some clues to things going wrong with manifested in frequency response graph:
We get similar clues in impedance versus frequency:
This is a very sensitive headphone so don't need much horsepower to drive it:
AKG K371 Headphone Listening Tests & EQ
First impression was a very good response albeit, with a tad too much bass and a bit of exaggerated highs and harshness. You really had to listen to find these though. I also found the vocals to be a tiny bit recessed. Overall, you could listen to these headphones and be perfectly fine without any equalization.
But we, at least I, want perfection so let's apply a bit of touch up as instructed by the frequency response:
I first boosted the lower treble and while that opened the sound up and nicely increased detail, the sound became somewhat bright. So I went after one of the peaks at 6800 and pulled that down. That fixed most of that. I initially had the bass pulled down some as you see in Band 1 crossed out above. I turned that off as it nicely countered the slightly sharpness that was left. Once there, this headphone was absolutely delightful to listen to. I could only find the slightest amount of harshness left (which could be magnification of what is in the music).
It was such a pleasure to listen to music with deep bass with and without EQ and hear those notes resonate in my ear even at very modest playback levels. Tracks like
Nachtschwärmen, by Regen:Tropfen were stunning in their impulsive bass notes:
And so was the rest of the spectrum. Notes come from every end of spectrum at no time do you say, "oh, why is that too high or too low." It is all balanced to near perfection.
Spatially without EQ the experience is fine. My boost of the lower treble however helps a lot here to get very good "soundstage" and layering of instruments. Mind you, it is not crazy nice like that if Sennheiser HD800s and such but it is "correct" and satisfying.
Conclusions
Some of you have been asking, even demanding to see a headphone that does the job without EQ. Well, the AKG K371 is it. My equalizations of it are subtle (but worthwhile) so you could indeed live without it. I do however highly recommend that you deploy EQ if you can.
You could say I am rubber stamping the Harman research and approach to headphone tonality. But such was not the case. I went into this review critically and thinking hard about what rating to give the headphone. I almost notched it down one step to avoid accusation of bias. But at the end, the truth is the truth. Years of research by Harman has resulted in creating headphone tonality that matches what I dream about getting out of best speakers in the world. To the extent their research goes after that sound (tonality of a good speaker in the room), it is natural that Harman and I land in the same spot.
Note that my strong positive recommendation for AKG K371 is for sound only. Physically, this headphone may not do it for you. It may get too hot around your ears, and the adjustment mechanism may annoy you or break. I leave that to you to decide.
------------
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/
Note: our company, Madrona Digital, carries various Harman brand products although not the AKG products.
The K371 is made out of plastic but has a nice finish which belies its cheap structure:
I especially like the feel of the pads. They are not huge but big enough to fit around my ears. Inside height of the pad is 2.51 inches. Inside width is 1.62 inches. With no depression, the pad depth to the driver is 0.8 inches. Outside diameter of the pad is 4 inches by 3 inches.
Three different cords are supplied which terminate into a 3-pin mini-XLR:
Let me warn you about something I hate about these headphones: the headband adjustment mechanism. It either gets stuck and doesn't move at all. Or all of a sudden moves a bunch of notches. I also see reports of the mechanism failing which means you have to send them back to Harman/AKG for repair (you pay shipping even under warranty).
Clamp pressure is a bit much especially if you wear glasses at first but gets better with some use. When I take them off, the pads are quite warm so likely in summer, they will not be comfortable if your room is not cool.
Note 1: The measurements you are about to see are preformed using standardized GRAS 45CA headphone measurement fixture. Headphone measurements require more interpretation than speaker tests and have more of a requirement for subjective testing as a result. In addition, comparison of measurements between different people doing it using different configurations requires fair bit of skill. So don't look for matching results. Focus on high level picture.
Getting the K371 seated did not require much work and indeed, measurements track some of the others I have seen using same fixture as I use.
AKG K371 Measurements
As usual we start with frequency response of K371. They are said to follow the Harman target. Let's see if that is the case:
This looks to be closest we have gotten to the target. Indeed in sub-bass where vast majority of headphones fall off, the K371 actually overachieves a bit. Then again the Harman fixture is a bit different than what the rest of us use so maybe in their fixture that was right on the money. Either way, during equalization and listening tests we will investigate this further.
Following down the curve, we have a dip around 3.8 to 3.9 kHz. It is a shame as past that the response envelop more or less follows our target.
We can subtract the response from the target and see the deviations:
Distortion is better than average:
The 94 dB line in blue shows extremely good performance. That keeps up even at 104 dBSPL.
Edit: forgot to include the absolute measurements:
Group delay gives us some clues to things going wrong with manifested in frequency response graph:
We get similar clues in impedance versus frequency:
This is a very sensitive headphone so don't need much horsepower to drive it:
AKG K371 Headphone Listening Tests & EQ
First impression was a very good response albeit, with a tad too much bass and a bit of exaggerated highs and harshness. You really had to listen to find these though. I also found the vocals to be a tiny bit recessed. Overall, you could listen to these headphones and be perfectly fine without any equalization.
But we, at least I, want perfection so let's apply a bit of touch up as instructed by the frequency response:
I first boosted the lower treble and while that opened the sound up and nicely increased detail, the sound became somewhat bright. So I went after one of the peaks at 6800 and pulled that down. That fixed most of that. I initially had the bass pulled down some as you see in Band 1 crossed out above. I turned that off as it nicely countered the slightly sharpness that was left. Once there, this headphone was absolutely delightful to listen to. I could only find the slightest amount of harshness left (which could be magnification of what is in the music).
It was such a pleasure to listen to music with deep bass with and without EQ and hear those notes resonate in my ear even at very modest playback levels. Tracks like
Nachtschwärmen, by Regen:Tropfen were stunning in their impulsive bass notes:
And so was the rest of the spectrum. Notes come from every end of spectrum at no time do you say, "oh, why is that too high or too low." It is all balanced to near perfection.
Spatially without EQ the experience is fine. My boost of the lower treble however helps a lot here to get very good "soundstage" and layering of instruments. Mind you, it is not crazy nice like that if Sennheiser HD800s and such but it is "correct" and satisfying.
Conclusions
Some of you have been asking, even demanding to see a headphone that does the job without EQ. Well, the AKG K371 is it. My equalizations of it are subtle (but worthwhile) so you could indeed live without it. I do however highly recommend that you deploy EQ if you can.
You could say I am rubber stamping the Harman research and approach to headphone tonality. But such was not the case. I went into this review critically and thinking hard about what rating to give the headphone. I almost notched it down one step to avoid accusation of bias. But at the end, the truth is the truth. Years of research by Harman has resulted in creating headphone tonality that matches what I dream about getting out of best speakers in the world. To the extent their research goes after that sound (tonality of a good speaker in the room), it is natural that Harman and I land in the same spot.
Note that my strong positive recommendation for AKG K371 is for sound only. Physically, this headphone may not do it for you. It may get too hot around your ears, and the adjustment mechanism may annoy you or break. I leave that to you to decide.
------------
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/
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