This is a review and detailed measurements of two versions of AKG K701 headphones: one made in Austria and one in China. They are on kind loan from a member and cost US $249.
Let's start with the China version. It is lightweight and doesn't impart feeling of a premium product. The large cups make them comfortable to wear though.
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 K701 has a self-adjusting mechanism which makes it hard to put high pressure on the test fixture. There was fair amount of variability in how I seated the unit.
AKG K701 MK II Chinese Measurements
Let's start with our usual frequency response measurements:
No matter what I did, I could not get the weak channel to match the other. What is there doesn't seem too bad. Here is our relative frequency response for purposes of EQ filter development:
The highly irregular shape combined with difficulty of measuring this headphone means an exact EQ is going to be hard to develop. But I am sure we can improve on the stock sound.
I was disappointed in distortion measurements:
That spike at 2 kHz is where our hearing is very sensitive. Its narrow width though indicates it is likely a resonance.
Group delay confirms that a secondary resonance (of the case?) at the same frequency as above:
Impedance was on the low to medium side:
Sensitivity is below average but not crazy so:
AKG K701 Austrian Made Measurements
Let's start with a shot of the unit itself:
Notice that the headband has bubbles in it which I found more comfortable. And the cup has the designation of "Made in Austria). Otherwise they two feel the same.
Channel matching here was actually worse than the Chinese version:
That is whopping 5 dB difference extending to almost 1 kHz! It may be measurement error or fitment but still, we don't see large variations like this often.
Comparing the Chinese to Austrian we get:
Given the degree of accuracy we have in measurements, I say that they are "the same." Where they are not the same is in distortion measurements:
So looks like there are minor variations in the mechanical aspects of the headphone that causes resonances at different frequencies. Overall, I prefer the Austrian one (right above).
Group delay now looks better:
AKG K701 Listening Tests and Equalization
I did my listening tests and EQ using the Austrian one. Out of the box response is not offensive. It seems a bit upper bass boosted and the rest sounds kind of ordinary. Fixing the response errors wakes up the sound nicely:
Bass distortion was not audible until you cranked it up. Then it would crackle a bit and progressively get worse. But it never pops or make you scared that something bad is going to happen.
With EQ, I could sit back and enjoy the sound and take advantage of the comfort of the unit.
Conclusions
Common between these two AKG headphones is rather complex response error and resonances. EQ helps with the former to create much better sound. Our measurements and headphone variations are too large to say convincingly that one version is worse than the other. Taken at face value, I would say the Austrian one is a bit better in distortion department. But sadly had more channel variation.
I can't recommend either version of AKG K701 without EQ. With EQ, they are fine.
-----------
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/
Let's start with the China version. It is lightweight and doesn't impart feeling of a premium product. The large cups make them comfortable to wear though.
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 K701 has a self-adjusting mechanism which makes it hard to put high pressure on the test fixture. There was fair amount of variability in how I seated the unit.
AKG K701 MK II Chinese Measurements
Let's start with our usual frequency response measurements:
No matter what I did, I could not get the weak channel to match the other. What is there doesn't seem too bad. Here is our relative frequency response for purposes of EQ filter development:
The highly irregular shape combined with difficulty of measuring this headphone means an exact EQ is going to be hard to develop. But I am sure we can improve on the stock sound.
I was disappointed in distortion measurements:
That spike at 2 kHz is where our hearing is very sensitive. Its narrow width though indicates it is likely a resonance.
Group delay confirms that a secondary resonance (of the case?) at the same frequency as above:
Impedance was on the low to medium side:
Sensitivity is below average but not crazy so:
AKG K701 Austrian Made Measurements
Let's start with a shot of the unit itself:
Notice that the headband has bubbles in it which I found more comfortable. And the cup has the designation of "Made in Austria). Otherwise they two feel the same.
Channel matching here was actually worse than the Chinese version:
That is whopping 5 dB difference extending to almost 1 kHz! It may be measurement error or fitment but still, we don't see large variations like this often.
Comparing the Chinese to Austrian we get:
Given the degree of accuracy we have in measurements, I say that they are "the same." Where they are not the same is in distortion measurements:
So looks like there are minor variations in the mechanical aspects of the headphone that causes resonances at different frequencies. Overall, I prefer the Austrian one (right above).
Group delay now looks better:
AKG K701 Listening Tests and Equalization
I did my listening tests and EQ using the Austrian one. Out of the box response is not offensive. It seems a bit upper bass boosted and the rest sounds kind of ordinary. Fixing the response errors wakes up the sound nicely:
Bass distortion was not audible until you cranked it up. Then it would crackle a bit and progressively get worse. But it never pops or make you scared that something bad is going to happen.
With EQ, I could sit back and enjoy the sound and take advantage of the comfort of the unit.
Conclusions
Common between these two AKG headphones is rather complex response error and resonances. EQ helps with the former to create much better sound. Our measurements and headphone variations are too large to say convincingly that one version is worse than the other. Taken at face value, I would say the Austrian one is a bit better in distortion department. But sadly had more channel variation.
I can't recommend either version of AKG K701 without EQ. With EQ, they are fine.
-----------
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/
Anyway, many thanks for nice review and "generation" comparison.
