AKG K240 55 Ohm Review (Headphone)

[solderdude]

OT: here a thought - reverse engineer a test by putting the AKG velours on the DT990's, and see what happens. Heaven or ouch?

No need to reverse engineer anything. Already did that test (and with other pads) years ago.

Solderdude - unless you and arminm are neighbors,

hardly... we are on opposite sides of the spinning globe.

I found my reference for the drivers being wired "inverse in absolute phase"

K240 Studio actually is wired in inverse absolute phase. It will offer no protection of anything though.
The phase going sharply from -120 to +60 degree at 4.5kHz within a narrow frequency range isn't helping fidelity of this headphone either.

Distortion is high too at 90dB SPL. 3rd harm at 250Hz is at an audible 2%. 2nd Harm at 90Hz is 10%

Poor headphone. Just good enough for monitoring voices and guitars.

 

[600_OHM]

I agree completely. Don't forget the splashy cymbals!

Oh, and checking out your other info, you taught me that the mod I was going to do by popping a hole in the back of my pleathers is called "fenestration". I didn't know there was a name for that. Thanks.

I won't belabor it any longer - when viewed from a hifi standpoint - yeah, these aren't it.

When viewed from a studio lens, those defects are actually beneficial long term for a very specific purpose. Sounds like a cop-out, but back then AKG's *main* market wasn't the hifi consumer really.

I think we're on the same page, just opposite sides of the coin.

Thanks for putting up with this. I have a lot of trust because of it.

 

[newaudioguy77]

I have listened to this headphone a few times at my cousins house. The bass distortion is definitely there. At first I thought the headphone was broken. This headphone is no good for music with a lot of bass. I didn't like the way it sounded at all.

 

[newaudioguy77]

K240s once were not from China. They cost lots more. My description of the sound would be about 180 degrees off from Amirs. I've not listened to the current versions. Would be interesting if someone could send you some of the older ones.

But lots of audio is made in China that performs well. AKG got their headphones made in China. Are you suggesting that potentially higher quality control would improve the sound quality of a headphone that should be identical anyway?

I remember my cousin bought them for half price. Later when I told him I didn't like the headphones, he did some research online. Eventually threw them in electronics recycling and the rest is history.

 

[600_OHM]

I have listened to this headphone a few times at my cousins house. The bass distortion is definitely there. At first I thought the headphone was broken. This headphone is no good for music with a lot of bass. I didn't like the way it sounded at all.

Couldn't have said it better. The K240 is the absolute wrong tool for listening to music for enjoyment.

It was primarily designed for audio-worker monitoring, where the job of final fidelity was left to another department. And if a studio guest or someone broke the headphone cord, an inexpensive spare pair was pulled off the shelf, rather than waste time having the engineering department slinging solder trying to fix the broken pair. If you actually *were* doing high fidelity, I guess at the time the better choice would have been the "DF" version. Lots of old history there.

What you experienced is what say an on-air radio DJ who has to listen to an audio product - and not all of it music - each and every day for 8 hours. They aren't sitting back enjoying music, but monitoring - all the while doing time calculations for spot-insertion, listening to what may be coming up next. Talking with guests or the production department off-air through the board ... That also means not going into a Moody-Blues dreamland while doing so with high fidelity cans and miscalculating your next spot.

I guess one way of saying it is that with the K240, you can file your taxes without error while having these on.

Because so much time has gone by since these came out, the "studio" moniker - for the job of monitoring, not mixing or mastering, gets totally confused. And sometimes the consumer simply doesn't know what the original purpose was or how it can be the wrong choice for high-fidelity applications.

For those that do know the original purpose, sometimes the K240 can be a source of entertainment due to the funk, knowing the different application needs. If you wanted to play like being a radio-dj at home, then these are it.

Despite that, and even despite measurements proving how these are the wrong tool for high-fidelity, like an old pair of jeans, it seems to live on.

 

[newaudioguy77]

Couldn't have said it better. The K240 is the absolute wrong tool for listening to music for enjoyment.

It was primarily designed for audio-worker monitoring, where the job of final fidelity was left to another department. And if a studio guest or someone broke the headphone cord, an inexpensive spare pair was pulled off the shelf, rather than waste time having the engineering department slinging solder trying to fix the broken pair. If you actually *were* doing high fidelity, I guess at the time the better choice would have been the "DF" version. Lots of old history there.

What you experienced is what say an on-air radio DJ who has to listen to an audio product - and not all of it music - each and every day for 8 hours. They aren't sitting back enjoying music, but monitoring - all the while doing time calculations for spot-insertion, listening to what may be coming up next. Talking with guests or the production department off-air through the board ... That also means not going into a Moody-Blues dreamland while doing so with high fidelity cans and miscalculating your next spot.

I guess one way of saying it is that with the K240, you can file your taxes without error while having these on.

Because so much time has gone by since these came out, the "studio" moniker - for the job of monitoring, not mixing or mastering, gets totally confused. And sometimes the consumer simply doesn't know what the original purpose was or how it can be the wrong choice for high-fidelity applications.

For those that do know the original purpose, sometimes the K240 can be a source of entertainment due to the funk, knowing the different application needs. If you wanted to play like being a radio-dj at home, then these are it.

Despite that, and even despite measurements proving how these are the wrong tool for high-fidelity, like an old pair of jeans, it seems to live on.

Thanks for your thoughtful response.

Directly from the AKG webpage:

The AKG K240 Studio over-ear, semi-open headphones are designed for professional applications such as mixing, mastering and playback. Their advanced 30 mm XXL transducers with patented Varimotion diaphragms deliver a wide dynamic range, increased sensitivity and high sound levels, while their semi-open design provides a solid bass range and extremely clear highs. With impressive accuracy, musicians, producers and engineers rely on the AKG K240 Studio to clearly hear mixing details, which has made these headphones a standard in recording settings.

During playback I could feel the entire cup resonating with each note. - same here with the K240!! -- this impacts the sound in a negative way, obviously. Plus high bass distortion. I thought something was broken inside the headphone driver lol.

If we are not mixing or mastering, perhaps a pair of Behringer's would be up for the task. I read on a few forums - the best place for a Behringer piece of gear/headphone is... "out of the signal path." Sounds like a good stand in for this AKG at a much lower cost.

 

[600_OHM]

Yep - if you read that marketing you'll notice it doesn't specifically mention music!

Even today, perhaps many of the marketers weren't even born when the K240 was introduced and may have themselves lost the plot.

The going concern a few years earlier was the problem of bass-shy source and playback, which tended to have the recording engineers totally blowing out the bass. The possible solution was to strive for bass-fidelity with the Sextets (six passive radiators) which proved costly for both the studio wanting multiple pairs, and manufacturing.

An easier solution was to hype the bass so that a more reasonable lower level of bass would be achieved during recording. Also remember that there was no "sub-bass" extension back when artists like T.REX were popular or during recorded vocal interviews. It would have been very easy to blow out totally flubby bass with things like this (nevermind if it actually had sub-bass cannonballs!)

So again, it was more of getting the mixing *levels* right, and not necessarily the fidelity. Part of getting the level right was not to introduce ear-fatigue. Like trying to mix the 65'th take of a Geico commercial. Fidelity is someone else's job.

Mastering? Yeah, dunno 'bout that. BUT, I suppose in a trained users hands, absolutely familiar with the frequency response and vagaries of the K240 for the last 30 years, it *could* be done by mentally compensating. Ahem.

Ultimately, the choice of the proper headphone manufacturer lays with the person doing the job. Put it this way - I'd get the mix mostly right with the K240's, rather than Sony 7506's every time. But that's just me. Someone else might nail it with a Berringer straight out of the box.

 

[newaudioguy77]

Yep - if you read that marketing you'll notice it doesn't specifically mention music!

Even today, perhaps many of the marketers weren't even born when the K240 was introduced and may have themselves lost the plot.

The going concern a few years earlier was the problem of bass-shy source and playback, which tended to have the recording engineers totally blowing out the bass. The possible solution was to strive for bass-fidelity with the Sextets (six passive radiators) which proved costly for both the studio wanting multiple pairs, and manufacturing.

An easier solution was to hype the bass so that a more reasonable lower level of bass would be achieved during recording. Also remember that there was no "sub-bass" extension back when artists like T.REX were popular or during recorded vocal interviews. It would have been very easy to blow out totally flubby bass with things like this (nevermind if it actually had sub-bass cannonballs!)

So again, it was more of getting the mixing *levels* right, and not necessarily the fidelity. Part of getting the level right was not to introduce ear-fatigue. Like trying to mix the 65'th take of a Geico commercial. Fidelity is someone else's job.

Mastering? Yeah, dunno 'bout that. BUT, I suppose in a trained users hands, absolutely familiar with the frequency response and vagaries of the K240 for the last 30 years, it *could* be done by mentally compensating. Ahem.

Ultimately, the choice of the proper headphone manufacturer lays with the person doing the job. Put it this way - I'd get the mix mostly right with the K240's, rather than Sony 7506's every time. But that's just me. Someone else might nail it with a Berringer straight out of the box.

Not sure if you read the entire portion of the product description that I copied and pasted from their website. These are marketing claims - that are targeted at a specific niche group. There is no other way to interpret these statements logically.

"With impressive accuracy, musicians, producers and engineers rely on the AKG K240 Studio to clearly hear mixing details, which has made these headphones a standard in recording settings."

- straight from the product page. I just copied it from the blurb I previously posted.

If it's not specifically for music...why do they mention musicians, producers, and *sound engineers?

Seems like you have a soft spot for these headphones. That is fine. I have nothing against AKG. I am only agreeing 100% with what Amir wrote in his review of them. It's because our impressions lined up exactly. I'm curious about the K872 and K812 - those look amazing. But do they sound amazing as well? Not sure.

 

[600_OHM]

I'm actually agreeing with both you and Amir! The 240's are a working monitoring tool, not a high-fidelity tool.

For better fidelity, I'll switch immediately to the K712's, or my Sennheisers. Use the right tool for the job.

Interestingly enough, you'll see the K712's touted as "reference studio headphones". I disagree. Their much better fidelity is actually - distracting - to the kind of work I used to do, and the last thing I needed was to be distracted. In another part of the studio where fidelity / sweetening was a much higher priority - then perhaps so.

I *DO* have a soft-spot for the 240's, but only because I know what their original purpose was/is. Had I not, I would have binned them immediately!

Ie, there's marketing - and there is matching the right tool to the right job. And sometimes this isn't down to measurements alone, although they can be a very handy guide.

 

[Jim Shaw]

I'm actually agreeing with both you and Amir! The 240's are a working monitoring tool, not a high-fidelity tool.

For better fidelity, I'll switch immediately to the K712's, or my Sennheisers. Use the right tool for the job.

Interestingly enough, you'll see the K712's touted as "reference studio headphones". I disagree. Their much better fidelity is actually - distracting - to the kind of work I used to do, and the last thing I needed was to be distracted. In another part of the studio where fidelity / sweetening was a much higher priority - then perhaps so.

I *DO* have a soft-spot for the 240's, but only because I know what their original purpose was/is. Had I not, I would have binned them immediately!

Ie, there's marketing - and there is matching the right tool to the right job. And sometimes this isn't down to measurements alone, although they can be a very handy guide.

I agree. I have the 240s hanging around here. I use them for long editing sessions with Davinci Resolve. What I need in such a headphone is long term comfort, light weight, and a fair replica of what's in an audio file. For comfort, I give them a 9 of 10. For usefulness at the console, I give them an 8. There, I'm listening for timing and continuity, not DC-to-light frequency response. But I have to understand that this forum is about near perfect reproduction of music. You guys sit and listen; I get that. If I were still recording quality music, I'd have a control room and good speaker-monitors. Like the big guys. For me, long-term comfort is the game and I can wear the 240s for hours - even forgetting they're on my head when I go for a coffee. Big surprise when the cord runs out.

I think it is somewhat important to judge a product by its use. In like fashion, I wouldn't hand a singer on stage a U67, nor would I use an SM58 for a studio vocal solo.

I have a pair of much more costly critical listening phones that I hardly ever wear for more than ten minutes. For tonal/timbral quality I use monitors. Like the big guys.

 

[SoundGuy]

I have the original K240 sextett from 1979 (the one Stevie Wonder and everyone else used). There was a reason everyone used this model - it was comfortable detailed and above all natural sounding and studios could afford to buy dozens of them.There is no comparison to the modern version. The compromises made to get a working 55 ohm model have never replicated the amazing detailed yet natural sound of the original - not even close. The original needs a beefy amplifier to work properly. They were designed with a beefy amplifier in mind. The design doesn’t work nearly as well when drivers are modified to work with flea amps. I would only recommend the original. That said, I do not recommend headphones at all - it bypasses the pinea and will always be a most unnatural sound as it removes the room response and detaches you from spatial cues with most of the sound sitting in your head. Anyone who can’t hear these issues or is able to ignore them obviously isn’t very sensitive to spatial queues in sound. Studios do not mix and master on headphones for these very reasons. Filters should not be used to correct amplitude deficiencies, as they introduce phase distortion - it is possible that those who aren’t sensitive to spatial cues may not have good phase sensitivity and may explain why some people are able to enjoy headphones more than others.

 

[solderdude]

Filters should not be used to correct amplitude deficiencies, as they introduce phase distortion - it is possible that those who aren’t sensitive to spatial cues may not have good phase sensitivity and may explain why some people are able to enjoy headphones more than others.

I have measured phase response of headphones with peaks that need correcting and guess what, the phase response hardly alters and in most cases even improves when applying filters (that correct amplitude).

 

[restorer-john]

The compromises made to get a working 55 ohm model have never replicated the amazing detailed yet natural sound of the original - not even close. The original needs a beefy amplifier to work properly. They were designed with a beefy amplifier in mind.

55 ohms is nothing to the amplifiers that were driving those cans (and others) back in the 70s. They were simply padded down outputs from power amp stages and voltage was not an issue.

 

[markanini]

That said, I do not recommend headphones at all - it bypasses the pinea and will always be a most unnatural sound as it removes the room response and detaches you from spatial cues with most of the sound sitting in your head. Anyone who can’t hear these issues or is able to ignore them obviously isn’t very sensitive to spatial queues in sound. Studios do not mix and master on headphones for these very reasons.

A bit hyperbolic but it would be a fair generalization if we are talking about music was mixed for 2.0/2.1 specifically. Beyond that we have some niche content like positional/binaural audio which absolutely surpasses 2.0 in spatial qualities. But more commonly on a song to song basis headphones do improve the listening experience. One reason is that every room is different, and speaker reproduction carries the spatial cues of the record in combination of spatial cues of the room. Needless to say those will not always play well together.

And consider the fact that the goal of isometric speaker placement in mixing rooms, close to he front wall, is designed to minimize room interactions. Headphones are basically one step removed from that by bypassing the outer ear. This unlocks some spatial potential, but also removes a spatial baseline coloration that the mixer might have assumed for the mix to sound right.

I'd go as far as saying people arguing sound stage capabilities between headphones are delusional, as that's a subset or spatial effects caused by room interactions.

 

[SoundGuy]

A bit hyperbolic but it would be a fair generalization if we are talking about music was mixed for 2.0/2.1. Beyond that we have some niche content like positional/binaural audio which absolutely surpasses 2.0 in spatial qualities. But more commonly on a song to song basis headphones do improve the listening experience. One reason is that every room is different, and speaker reproduction carries the spatial cues of the record in combination of spatial cues of the room. Needless to say those will not always play well together.

And consider the fact that the goal of isometric speaker placement in mixing rooms, close to he front wall, is designed to minimize room interactions. Headphones are basically one step removed from that by bypassing the outer ear, thus the fixed max azimuth determined by the distance between the speakers and listener. This unlocks some spatial potential, but also removes a spatial baseline that the mixer might have expected for the reproduction to sound as intended.

I'd go as far as saying people arguing sound stage capabilities between headphones are delusional, as that's a subset or spatial effects caused by room interactions.

Agreed. It is also more than just spatial cues that are available from speakers in a room. A correct balance of sound reflections are an important source of audio information and listening pleasure, as Sabine studied and concluded. Concert halls are highly engineered to achieve appropriate reverberation.

 

[markanini]

Agreed. It is also more than just spatial cues that are available from speakers in a room. A correct balance of sound reflections are an important source of audio information and listening pleasure, as Sabine studied and concluded. Concert halls are highly engineered to achieve appropriate reverberation.

That said there's a lot of stereo music that can be enjoyed on headphones. Many mixers now a days check mixes on headphones and generally do engineering that's less system dependent. You might not be ruining the sound by headphones any more than by listening through different speakers in a different room.

It's just that it needs a big fat YMMV

 

[sblrog]

I am sure there are plenty of portable sources that will give a really bad result if you combine them with the K240 Monitor, I am just saying that this is not necessarily the case. The power requirements to make a headphone like the K240 Monitor sound well are vastly overrated.

How much power do you think you need to drive a 600 ohm 94dB/mW headphone like the K240 Monitor to 100 dB (which is louder than I can listen to)? There is enough energy in a rechargeable AAA nimH battery to power a headphone like that under those conditions for about 100 hours, except that most of the power is lost in the wire, the mp3 circuits, and due to the internal resistance of the battery. But in reality the amount of energy needed to power a headphone like that to reasonable levels is miniscule.


What benefit would that be? I can guarantee you that if you do an A/B blind test between a good portable source (even a battery operated mp3 player) and a transparent amp like the O2, the results would be statistically insignificant. This is all a myth in my experience.

I'll share my experience. As always, YMMV.

Picked up a used 600 ohm K240 Monitor a few weeks ago. My phone failed miserably to drive it, but the price was great for this classic, so I took it. Once I got home, my laptop (Realtek High Definition Audio card) seemed to drive it fine at about 60% volume. But there was pretty bad sibilance. Tried to EQ that out, which was not entirely satisfactory due to collateral damage to neighboring frequencies. Then I started to notice occasional distortion in a few songs. Didn't want to spring for an amp, so I plugged it into the headphone jack of a Behringer Xenyx 502 mixer that I had and dialed down the laptop volume. That took care of the distortion on those songs and, surprisingly to me, also got rid of most of the sibilance (I guess that was at least partly distortion related?). Found more songs with distortion, so dialed down the laptop volume even more (it's now at 10%). I'm ecstatic that I got this really good sounding set of headphones. But in my case, some amplification helped tremendously. Maybe my laptop sound card really sucks.

 

[PeteL]

I'll share my experience. As always, YMMV.

Picked up a used 600 ohm K240 Monitor a few weeks ago. My phone failed miserably to drive it, but the price was great for this classic, so I took it. Once I got home, my laptop (Realtek High Definition Audio card) seemed to drive it fine at about 60% volume. But there was pretty bad sibilance. Tried to EQ that out, which was not entirely satisfactory due to collateral damage to neighboring frequencies. Then I started to notice occasional distortion in a few songs. Didn't want to spring for an amp, so I plugged it into the headphone jack of a Behringer Xenyx 502 mixer that I had and dialed down the laptop volume. That took care of the distortion on those songs and, surprisingly to me, also got rid of most of the sibilance (I guess that was at least partly distortion related?). Found more songs with distortion, so dialed down the laptop volume even more (it's now at 10%). I'm ecstatic that I got this really good sounding set of headphones. But in my case, some amplification helped tremendously. Maybe my laptop sound card really sucks.

My Realtek audio output (on a HP Probook G9) also do suck. I'd be interested to see that measured sometime.

 

[sblrog]

My Realtek audio output (on a HP Probook G9) also do suck. I'd be interested to see that measured sometime.

Hmm, not getting the same distortion coming from my phone (Motorola G9 Play -> Behringer Xenyx 502 -> K240 M). So, disregard most of what I said above about the K240 M, other than it can't be driven by this phone.

 

[sblrog]

My Realtek audio output (on a HP Probook G9) also do suck. I'd be interested to see that measured sometime.

Hey Pete,

I updated the drivers for my Realtek High Definition Audio and it stopped sucking.