AKG K371 Review (closed back headphone)

[markanini]

I only noticed microphonics when using them as monitors while playing bass guitar and it was pretty bad.

 

[Jeromeof]

Quick question about the seal with these headphones - I wear glasses and I have read that this will lower the bass response a little. So, what I am wondering would this bring the sound more in line with their cheaper sibling (the K361). But if it did would wearing glasses with the K361 cause a similar reduction in lower frequencies.

So effectively I am asking if I am as well getting the K371 even if I might only get a similar low frequency response to the K361 which I also see are lots of peoples preference anymore for a harman curve headphone with slightly less bass than the K371.

 

[solderdude]

seal loss for K371:

K361 frequency response (also different amount of seal)

K371 vs K361 (perfect seal) :

 

[MayaTlab]

Quick question about the seal with these headphones - I wear glasses and I have read that this will lower the bass response a little. So, what I am wondering would this bring the sound more in line with their cheaper sibling (the K361). But if it did would wearing glasses with the K361 cause a similar reduction in lower frequencies.

So effectively I am asking if I am as well getting the K371 even if I might only get a similar low frequency response to the K361 which I also see are lots of peoples preference anymore for a harman curve headphone with slightly less bass than the K371.

Rtings measures bass response up to a few hundred Hz on real humans, this might give you some idea of the sort of variation you may expect :

Headphones v1.5 - Graph Tool

www.rtings.com

Where you yourself will fall in that delta is impossible to predict without measuring them in situ like Rtings does.

 

[Jeromeof]

Rtings measures bass response up to a few hundred Hz on real humans, this might give you some idea of the sort of variation you may expect :

Headphones v1.5 - Graph Tool

www.rtings.com

Where you yourself will fall in that delta is impossible to predict without measuring them in situ like Rtings does.

Thanks, interesting, that is allot of variation on the left channel alright.
I ordered a pair from Amazon earlier so I will see over the weekend what I think with my specific usage (and send them back if I am not happy). After trying the Truthear Zero's IEM's, I decided I wanted a Harman curve closed back headphones (I was previously using some old Monoprice headphones).

 

[oleg87]

Quick question about the seal with these headphones - I wear glasses and I have read that this will lower the bass response a little. So, what I am wondering would this bring the sound more in line with their cheaper sibling (the K361). But if it did would wearing glasses with the K361 cause a similar reduction in lower frequencies.

So effectively I am asking if I am as well getting the K371 even if I might only get a similar low frequency response to the K361 which I also see are lots of peoples preference anymore for a harman curve headphone with slightly less bass than the K371.

I'd be more concerned with the consistency of whatever seal you get wearing glasses - the K371's bass response is rather fiddly and easily perturbed for me.

 

[Robbo99999]

Rtings measures bass response up to a few hundred Hz on real humans, this might give you some idea of the sort of variation you may expect :

Headphones v1.5 - Graph Tool

www.rtings.com

Where you yourself will fall in that delta is impossible to predict without measuring them in situ like Rtings does.

Ah, brilliant, I don't look in RTings much, and had thought that was frequency response consistency on the mannequin, but I can see from what you're saying that it's on real humans - that's pretty useful to use for comparing seal issues between different headphones. (I'll take a look at how my different headphones perform in that test to see if equates loosely to what I've experienced through listening).

 

[staticV3]

(I'll take a look at how my different headphones perform in that test to see if equates loosely to what I've experienced through listening).

probably more practical in this format: https://www.rtings.com/headphones/tools/table/93152

Edit: Hmmm

 

[solderdude]

I'd be more concerned with the consistency of whatever seal you get wearing glasses - the K371's bass response is rather fiddly and easily perturbed for me.

I was most displeased by how the balance of the bass shifted (due to seal issues) when moving my head around. Very annoying.

Besides... when wearing glasses with thin arms pressed against the skin at the point where the pads are you may not even have seal issues.
They will be more severe with thicker arms or arms that do not rest against the skin and allow for leakage between arm and skin.
So there is no consistency that's why I test with increasing seal breakage by using different glasses pushed between the pads and fixture.
That fixture is not hard plastic or rubber but is covered with cell foam that has a very similar compliance as skin.

 

[thyristor]

Anyone know if the BT version supports LDAC or is it SBC and AAC only?

I love the wired version so much and the BT is tempting for convenience.

 

[Berwhale]

Anyone know if the BT version supports LDAC or is it SBC and AAC only?

I love the wired version so much and the BT is tempting for convenience.

The latter... https://help.harmanpro.com/which-codecs-are-supported-by-k361-bt-and-k371-bt-headphones

 

[Robbo99999]

probably more practical in this format: https://www.rtings.com/headphones/tools/table/93152

Edit: Hmmm
View attachment 238161

Late reply, I just totally missed this amongst my watched threads! That's really quite interesting, shows that open backed headphones are a lot more consistent between individuals, meaning you could end up with some very crazy frequency responses in closed back headphones (on average) between different people!

 

[Robbo99999]

probably more practical in this format: https://www.rtings.com/headphones/tools/table/93152

Edit: Hmmm
View attachment 238161

Have they really measured that many more closed back headphones than open backed headphones? I'm guessing you would have put all the data on there, but seems strange that they've measured so many closed back headphones vs open back.

 

[staticV3]

Have they really measured that many more closed back headphones than open backed headphones?

you could've checked this twice in the time it took you to type out that message, by just clicking on the link that you're quoting..

 

[Robbo99999]

you could've checked this twice in the time it took you to type out that message, by just clicking on the link that you're quoting..
View attachment 242903

Ha, true, well thanks, at least you've helped out some other people too! Strange that they've measured so many more closed backs vs open backs recently then. And I'm assuming you selected "recent" test methodology rather than all their history as praps the recent methodology is only comparable to itself. Otherwise, I guess if you were able to compare all their history of measured headphones that the open vs closed back would even up in terms of numbers tested of each. (See, there's still some value in our conversation.)

 

[staticV3]

The graph I posted a while ago shows all closed-back and open-back headphones in rtings' database that use a "Recent" test methodology.
Semi-Open were omitted.

 

[Berwhale]

Have they really measured that many more closed back headphones than open backed headphones?

They're testing a lot of wireless, noise cancelling headphones which will inevitably be closed back.

 

[bevok]

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:

View attachment 107868

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:

View attachment 107869

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:

View attachment 107870

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:

View attachment 107871

Distortion is better than average:

View attachment 107872

The 94 dB line in blue shows extremely good performance. That keeps up even at 104 dBSPL.

Edit: forgot to include the absolute measurements:

View attachment 108584

Group delay gives us some clues to things going wrong with manifested in frequency response graph:
View attachment 107873

We get similar clues in impedance versus frequency:
View attachment 107874

This is a very sensitive headphone so don't need much horsepower to drive it:

View attachment 107875

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:
View attachment 107876

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/

Thank you, I’ve made these my first ‘audiophile’ headphone and am very pleased with the sound thus far. Look forward to playing with the EQ. Plexamp has a nice eq feature for those who don’t have Roon and want to use an iOS device.

 

[mackat]

I finally just decided to buy a pair of these, out of curiosity.

You can currently get them from Adorama for only $119 as part of a podcaster kit, which also comes with a microphone: https://www.adorama.com/ak512201000.html

 

[Zwuckel]

Hi, I got a pair for christmas and think I have channel imbalance. How can I check for sure? I still would have warranty. Subjective I trim the right channel with about -2.0 dB with my Qudelix. Is there any issue long term if I keep the pair as it is?