This is a review and detailed measurements of the AKG K271 MKII closed back headphone. It is on kind loan from a member and costs US $118 on Amazon including prime shipping.
I understand if you buy them new, you get two sets of pads. The sample I have only came with the "leather" one:
The headphone is ultra light and feels quite plasticky. You certainly don't get a feeling that you bought something of value. The pads are quite shallow (maybe they are worn?) to the tune of 16 mm, the lowest I have measured on any over the ear headphone. As such, they pushed the artificial ear lobes on my fixture and my own ear. I did not mind it much though. As mentioned, they are extremely light:
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!
The K271 has a self-adjusting mechanism which makes it hard to put high pressure on the test fixture. I could see some air gaps when I fit it there and observed high variability in bass performance. So be mindful of this when you see the follow on measurements.
AKG K271 ohm Measurements
Let's start with our usual frequency response measurements:
At first blush, this looks scary bad. But when you look past the kinks here and there, the compliance with our target curve in the critical range of 200 Hz to 3 kHz is quite good! Below that we have messy bass response but that could be due to measurement error as evidenced by green channel doing better (which I could confirm visually to be the case). At the highest frequencies we have a bit of excess energy but not much.
Here is our relative frequency response measurement:
The relative distortion graph looks really bad in bass because the response is dropping while distortion is increasing there:
Maybe the super light weight of this headphone and not so tight fit on the fixture is causing its body to resonate or something. We will circle back to this (sort of) when we perform our listening tests.
Group delay just confirms there are point frequency issues in this design:
Of note, there is no fuzziness in mid frequencies yet as you will read in the subjective section, there is very good spatial effects.
Impedance is on the low side and somewhat variable:
Sensitivity is a bit better than average:
Combined with lowish impedance, you should be able to drive the K271 with portable devices.
AKG K271 Listening Tests
While not perfect, out of the box tonality was close to what I expected to hear. My reference tracks immediately sounded (almost) right. Some equalization with substantial boost in bass transformed this headphone's performance:
Wow or wow! This thing has incredible bass now and very nice spatiality. I ran the tests yesterday and today I am still listening to them! Track after track sounds wonderful.
As to bass distortion, I can't hear it unless I blast it and then it starts to rattle and such. But at any reasonable level, it sounds very clean counter to the measurements.
Was just listening to the track, Je Suis Une Fleure, from the album Best Kept Secretes Part 2 by Shigeru Umebayashi makes you think you have died and gone to heaven:
Conclusions
What is the old saying? Don't judge a book by its cover? So is the story of AKG K271. Out of the box it is mostly fine but not exciting. Add some EQ and this headphone transforms into jewel, something that is hard to find in closed back headphones. The large cups provide for very nice spatial effects. Combine this with the low price and you have a winner here.
I am going to recommend the AKG K271. With equalization, it almost earns a golfing panther! I would give it such if I was not worried about you all chasing me out of town that such a cheap headphone with seemingly messy measurements would achieve such.
-----------
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/
I understand if you buy them new, you get two sets of pads. The sample I have only came with the "leather" one:
The headphone is ultra light and feels quite plasticky. You certainly don't get a feeling that you bought something of value. The pads are quite shallow (maybe they are worn?) to the tune of 16 mm, the lowest I have measured on any over the ear headphone. As such, they pushed the artificial ear lobes on my fixture and my own ear. I did not mind it much though. As mentioned, they are extremely light:
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!
The K271 has a self-adjusting mechanism which makes it hard to put high pressure on the test fixture. I could see some air gaps when I fit it there and observed high variability in bass performance. So be mindful of this when you see the follow on measurements.
AKG K271 ohm Measurements
Let's start with our usual frequency response measurements:
At first blush, this looks scary bad. But when you look past the kinks here and there, the compliance with our target curve in the critical range of 200 Hz to 3 kHz is quite good! Below that we have messy bass response but that could be due to measurement error as evidenced by green channel doing better (which I could confirm visually to be the case). At the highest frequencies we have a bit of excess energy but not much.
Here is our relative frequency response measurement:
The relative distortion graph looks really bad in bass because the response is dropping while distortion is increasing there:
Maybe the super light weight of this headphone and not so tight fit on the fixture is causing its body to resonate or something. We will circle back to this (sort of) when we perform our listening tests.
Group delay just confirms there are point frequency issues in this design:
Of note, there is no fuzziness in mid frequencies yet as you will read in the subjective section, there is very good spatial effects.
Impedance is on the low side and somewhat variable:
Sensitivity is a bit better than average:
Combined with lowish impedance, you should be able to drive the K271 with portable devices.
AKG K271 Listening Tests
While not perfect, out of the box tonality was close to what I expected to hear. My reference tracks immediately sounded (almost) right. Some equalization with substantial boost in bass transformed this headphone's performance:
Wow or wow! This thing has incredible bass now and very nice spatiality. I ran the tests yesterday and today I am still listening to them! Track after track sounds wonderful.
As to bass distortion, I can't hear it unless I blast it and then it starts to rattle and such. But at any reasonable level, it sounds very clean counter to the measurements.
Was just listening to the track, Je Suis Une Fleure, from the album Best Kept Secretes Part 2 by Shigeru Umebayashi makes you think you have died and gone to heaven:
Conclusions
What is the old saying? Don't judge a book by its cover? So is the story of AKG K271. Out of the box it is mostly fine but not exciting. Add some EQ and this headphone transforms into jewel, something that is hard to find in closed back headphones. The large cups provide for very nice spatial effects. Combine this with the low price and you have a winner here.
I am going to recommend the AKG K271. With equalization, it almost earns a golfing panther! I would give it such if I was not worried about you all chasing me out of town that such a cheap headphone with seemingly messy measurements would achieve such.
-----------
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/
