This is a review and detailed measurements of the AKG K240 55 ohm Semi-Open, "Professional Studio" Headphones. It is on kind loan from a member and costs US $69 from Amazon including Prime shipping.
Note: our company, Madrona Digital carries Harman products. AKG is owned by Harman so feel free to read as much bias as you feel necessary into this review.
The K240 has a kind of retro "aviator" look to it:
The sample I have has thicker velour pads as you see. Owner was kind enough to also supply the original, thin pads but they were severely degraded so I did not use them. There were also a couple of filters included. I am not sure if they were part of the original design and not used when the pads were swapped or what. No, I am not going to measure this headphone twice. Not everything needs to be a science a project.
These are very light headphones owing to thin plastics used:
During playback I could feel the entire cup resonating with each note.
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 have confirmed 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!
Fitting these headphones on the fixture was a challenge at first as the headband was simply too large. The cups would not remotely seal. After squeezing every bit of adjustment it allowed, I managed to get 90% or better seal. Looking at other measurements, seems like correlation is high so I went with it.
AKG K240 55 Ohm Measurements
As usual we start with our frequency response:
Every time I measure a headphone I hope to see something close to target, I get disappointed most of the time and this is no exception. Besides the bass roll off we also have shortfall in the critical region of 1 to 2 kHz which establishes how "open" a headphone sounds. There is also some lack of treble energy around 4 to 5 kHz with a bit of peaking around 8 kHz. Overall I expect this headphone to sound quite "unexciting." But we shall see. Here is the deviation from our target:
Deviation from target response is one thing but what's up with this?
Group delay indicates some interference pattern but that is common:
Sensitivity is a bit below average:
Impedance is stated at 55 ohm but it rises to three times as much in lower frequencies, and double that at highest:
AKG K240 Listening Tests and Equalization
I could not listen to the stock sound of this headphone for more than a few seconds. It is deeply compressed and dull sounding with a bit of ting once in a one. Equalization is absolutely mandatory for good sound. I developed one quickly by eye. A more proper one requires some automation or more work:
This gave the headphone much more life with better bass, mid-range and treble response.
Spatial qualities were non-existent and didn't develop with EQ but the sound was more open.
Conclusions
Please pardon me for being crude but if I had to listen to these headphones without EQ, I would give up on being an audiophile! None of my reference tracks sounded exciting with this headphone and many of these tracks are picked because they tend to sound good on many gear! What business does AKG have to call these "Professional Studio" headphones? What possible asset do they bring to pro world? Technically there is nothing you can hang your hat on here. How it gets more than 7,000 reviews on Amazon averaging 4.5 stars is beyond me. I don't care how cheap a headphone is. It needs to be bring a minimum level of fidelity and this headphone does not.
I can not recommend the AKG K240 55 ohm. If you are stuck with it, be sure to use equalization to breath some much needed life into it.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Note: our company, Madrona Digital carries Harman products. AKG is owned by Harman so feel free to read as much bias as you feel necessary into this review.
The K240 has a kind of retro "aviator" look to it:
The sample I have has thicker velour pads as you see. Owner was kind enough to also supply the original, thin pads but they were severely degraded so I did not use them. There were also a couple of filters included. I am not sure if they were part of the original design and not used when the pads were swapped or what. No, I am not going to measure this headphone twice. Not everything needs to be a science a project.
These are very light headphones owing to thin plastics used:
During playback I could feel the entire cup resonating with each note.
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 have confirmed 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!
Fitting these headphones on the fixture was a challenge at first as the headband was simply too large. The cups would not remotely seal. After squeezing every bit of adjustment it allowed, I managed to get 90% or better seal. Looking at other measurements, seems like correlation is high so I went with it.
AKG K240 55 Ohm Measurements
As usual we start with our frequency response:
Every time I measure a headphone I hope to see something close to target, I get disappointed most of the time and this is no exception. Besides the bass roll off we also have shortfall in the critical region of 1 to 2 kHz which establishes how "open" a headphone sounds. There is also some lack of treble energy around 4 to 5 kHz with a bit of peaking around 8 kHz. Overall I expect this headphone to sound quite "unexciting." But we shall see. Here is the deviation from our target:
Deviation from target response is one thing but what's up with this?
Group delay indicates some interference pattern but that is common:
Sensitivity is a bit below average:
Impedance is stated at 55 ohm but it rises to three times as much in lower frequencies, and double that at highest:
AKG K240 Listening Tests and Equalization
I could not listen to the stock sound of this headphone for more than a few seconds. It is deeply compressed and dull sounding with a bit of ting once in a one. Equalization is absolutely mandatory for good sound. I developed one quickly by eye. A more proper one requires some automation or more work:
This gave the headphone much more life with better bass, mid-range and treble response.
Spatial qualities were non-existent and didn't develop with EQ but the sound was more open.
Conclusions
Please pardon me for being crude but if I had to listen to these headphones without EQ, I would give up on being an audiophile! None of my reference tracks sounded exciting with this headphone and many of these tracks are picked because they tend to sound good on many gear! What business does AKG have to call these "Professional Studio" headphones? What possible asset do they bring to pro world? Technically there is nothing you can hang your hat on here. How it gets more than 7,000 reviews on Amazon averaging 4.5 stars is beyond me. I don't care how cheap a headphone is. It needs to be bring a minimum level of fidelity and this headphone does not.
I can not recommend the AKG K240 55 ohm. If you are stuck with it, be sure to use equalization to breath some much needed life into it.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
