I have experience with some AKGs. It looks like the KRK 8400's are similar to the AKG K141/142 and K240/242.
 
Anyway, I found the soundstage on the K272 to be wide enough to freak me out at first. I can't imagine a wider sound that I'd enjoy without a lot of forced hearing adaptation. Also, the K272 sounded excellent with just about everything that could be thrown at it.
 
However, I have the most experience with the K171, which are made for monitoring drums and vocals. These are abslutely fantastic on drums (and my voice), and the K271/272 are so similar in sound (same drivers) that the added comfort and touch more bass will be welcome. Even though the K171 is designed for drums and vocals, I haven't found a genre that dousn't sound good on them... but I'm not a basshead and the bass rolls off on these enough that some dubsteppers may want to look at something other than the K171. I just give them +4dB around 30Hz and +2dB around 60Hz and I'm good with any music. Also the K171 is the most detailed of them all but only by a thin margin. It may have to do with the fact that I have a few more hundred hours on these than the other two models.
 
Of the three AKGs I've had (K171, K272, K142), only the K142 didn't really seem to make use of burn-in. Maybe the sound widened a bit, but I couldn't really tell a difference. The K272 needed between 55-80 hours to tighten and for the bass to wake up. The K171 got about 70 hours. None of these cans are sibilant, but the K171 was closest to being sibilant of the bunch. Grados, by comparison, were like having a cat scratch my eardrums. I still have the K171 and K142 and use them at least 4 times a week. The K272 I gifted away. They sure were comfortable.
 
All of these AKG's have supremely good headbands. The 7's isolate very nicely. The 4's are open-backed but leak very little sound. Good design. The 27X's are the most comfortable headphone ever made, and are very light weight.
 
One thing you guys need to know is that AKG attenuates the bass on their closed cans because of resonance. Just pump the EQ and you'll see exactly what I'm talking about. So the old wisdom of closed cans having more bass is foolishness when it comes to AKG's. The 4's (141, 142, 240, 242) all have much more bass and are open backed. But the high-bass/low-mid bump at around 125Hz is annoying as heck. I much prefer the sound of the 7's over the 4's, but the open can accepts EQ much better.
 
All these AKG's make use of current buffer amps with low output impedance. Not all amps sound good on these. They max out at 3.3V and 60mA. Many amps don't supply that much amperage, but have no problem with the voltage. Something like the Objective2 from JDS Labs with the high gain resisters clipped (making it unity gain on one setting and 2.5x on the other) is the way to go.
 
As for the K550, I think I'd rather wait until I have an outboard DSP setup to my liking before I pick these up. Maybe I'll like the soundstage, maybe not. The shrill highs compared to the headphones you all have mentioned make me think that they have better extended highs, unlike the very rolled off highs of the DT1350 or LCD-2's... and the AKG's I wrote all about.

IMO the KRK KNS-8400 doesn't sound much like the K240 Studio. K240 has much more bass, but maybe less sub-bass. Maybe closer to the K271? I haven't heard that though.
The KNS-8400 is most similar to the Q701 (which isn't a clone of the K701/K702 to my ears, but similar). I've found the Q701 with my setup to be much warmer than the K701 and seems to have fuller sounding mids, just like the 8400. I had the K702 with the exact same setup multiple times. I can't really think of any headphone that sounds any closer to the 8400 than the Q701.
 
Seriously when I was gaming and playing Skyrim, the 8400 and Q701 sounded very, very similar. Couldn't believe it! The only thing that jumped out at me is that the mids were slightly more fuller sounding and the soundstage was smaller on the 8400. Sound clarity was pretty even, but the 8400 might have the edge in detail. Want a gaming headphone that sounds like the Q701 that's closed? Get the 8400!
 
I was using both with a Headroom Micro amp, which seems to me the perfect match for both headphones.
 
Sorry, I should probably shut up about the 8400, this is the K550 thread after all..
Quote:

funkmeister said:

I have experience with some AKGs. It looks like the KRK 8400's are similar to the AKG K141/142 and K240/242. I found the soundstage on the K272 to be wide enough to freak me out. I can't imagine a wider sound that I'd enjoy without a lot of forced hearing adaptation. Also, the K272 sounded excellent with just about everything that could be thrown at it.
 
I also have the most experience with the K171, which are made for monitoring drums and vocals. These are abslutely fantastic on drums (and my voice), and the K271/272 are so similar in sound (same drivers) that the added comfort and touch more bass will be welcome.
 
Of the three AKGs I've had (K171, K272, K142), only the K142 didn't really seem to make use of burn-in. The K272 needed between 55-80 hours to tighten up. The K171 got about 70 hours. None of these cans are sibilant, but the K171 was closest to being sibilant of the bunch. Grados, by comparison, were like having a cat scratch my eardrums. I still have the K171 and K142 and use them at least 4 times a week. The K272 I gifted away.
 
All of these AKG's have supremely good headbands. The 7's isolate very nicely. The 4's are open-backed but leak very little sound. Good design. The 27X's are the most comfortable headphone ever made, and are very light weight.
 
One thing you guys need to know is that AKG attenuates the bass on their closed cans because of resonance. Just pump the EQ and you'll see exactly what I'm talking about. So the old wisdom of closed cans having more bass is foolishness when it comes to AKG's. The 4's (141, 142, 240, 242) all have much more bass and are open backed. But the high-bass/low-mid bump at around 125Hz is annoying as heck. I much prefer the sound of the 7's over the 4's, but the open can accepts EQ much better.
 
All these AKG's make use of current buffer amps with low output impedance. Not all amps sound good on these. They max out at 3.3V and 60mA. Many amps don't supply that much amperage, but have no problem with the voltage. Something like the Objective2 from JDS Labs with the high gain resisters clipped (making it unity gain on one setting and 2.5x on the other) is the way to go.
 
As for the K550, I think I'd rather wait until I have an outboard DSP setup to my liking before I pick these up. Maybe I'll like the soundstage, maybe not. The shrill highs sompared to the headphones you all have mentioned make me think that they have better extended highs, unlike the very rolled off highs of the DT1350 or LCD-2's... and the AKG's I wrote all about.

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Quote:

tdockweiler said:

IMO the KRK KNS-8400 doesn't sound much like the K240 Studio. K240 has much more bass, but maybe less sub-bass. Maybe closer to the K271? I haven't heard that though.
The KNS-8400 is most similar to the Q701 (which isn't a clone of the K701/K702 to my ears, but similar). I've found the Q701 with my setup to be much warmer than the K701 and seems to have fuller sounding mids, just like the 8400. I had the K702 with the exact same setup multiple times. I can't really think of any headphone that sounds any closer to the 8400 than the Q701.
 
Seriously when I was gaming and playing Skyrim, the 8400 and Q701 sounded very, very similar. Couldn't believe it! The only thing that jumped out at me is that the mids were slightly more fuller sounding and the soundstage was smaller on the 8400. Sound clarity was pretty even, but the 8400 might have the edge in detail. Want a gaming headphone that sounds like the Q701 that's closed? Get the 8400!
 
I was using both with a Headroom Micro amp, which seems to me the perfect match for both headphones.
 
Sorry, I should probably shut up about the 8400, this is the K550 thread after all..


 

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But it's so hard when they're so good!
 

Quote:

electropop said:

No. 

 
Compared to my reference (HD25-1, SRH840, K272HD, 8.35D/QP805), the 8400 do not isolate that well and leak more. But alas, even the German Quarts aren't really as good as the KRK's. Not as clear overall, but I'm liking the indestructibility of them... 
 
I wouldn't name any other "closed" headphones I've tried, simply because their intended purpose lies elsewhere. For the KRK's intended purpose, they do not isolate (in either direction) as well as they should (not sure if could without sacrificing something). 
 
By the way, the K272 is still an amazing headphone among all the fancy newcomers. Most comfortable design on a closed headphone and competes with the 8400. Bass-articulation might even be better... So do give them a try if you get a chance! They do work great out of portables, but benefit from a better source and amp, much unlike many others. 

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Yea, the Qp805 surprised me a little bit.  I'm very familiar with MB Quart "house sound", not just in the headphone sense but the external setups as well.  Honestly, the 805 just sounded different.  I think it has a very fun signature, but certainly not a very analytical one.  The mids are a tad murky to me and almost have a "hall" presence to them.  The bass is pretty meaty as well.  Fun can for sure, but certainly not my ideal sound, or anything like any of the other Quart stuff I have tried.  The mids in the QP400 and SP-1 are far superior.
 
I really do need to try the 272.  It might just be the can I'm looking for.  Ideally they'd have some sort of case and fold, and maybe a detachable cable (do they?).  The comfort sounds like a huge plus though!  As long as they don't leak much I might just have a winner.
 
Still interested in the K550 though, we'll see if impressions change as people listen more.
 
As for the KRK goes, the 8400 is a gem for the price.  It is good that it is starting to get some recognition around here because I feel it is well earned.
 
EDIT: Also, the QP805 is the 8.300 equivalent, not the 8.35.  I'm not even sure the 805 is identical to the 8.300.  Tweaks could have been made.  My guess is they are extremely similar, though

 
Quote:

r-audiohead said:

EDIT: Also, the QP805 is the 8.300 equivalent, not the 8.35.  I'm not even sure the 805 is identical to the 8.300.  Tweaks could have been made.  My guess is they are extremely similar, though

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I'm pretty sure the QP 805 HD looks likes the GMP 8.300 D, but sounds entirely different. Specs are different too.
The 8.300 is a rather bright headphone, with lean bass. Still fun to listen to because the sound is quick and liquid (toe tapping). Sort of a closed K-400, without the wide soundstage.
I had to put some felt on the drivers of the 8.300D to tame the brightness and make the sound fuller.
Mids aren't murky, but revealing.
From what I've read in this thread, I don't think the K550 will be any better than the GMP 8.300, except for a wider soundstage and airier presentation
 

Quote:

tiemen said:

 


I'm pretty sure the QP 805 HD looks likes the GMP 8.300 D, but sounds entirely different. Specs are different too.
The 8.300 is a bright, analytical headphone, with lean bass. Still fun to listen to because the sound is quick and liquid (toe tapping). Sort of a closed K-400, without the wide soundstage.
I had to put some vilt on the drivers of the 8.300D to tame the brightness and make the sound fuller.
Mids aren't murky, but revealing.
From what I've read in this thread, I don't think the K550 will be any better than the GMP 8.300, except for a wider soundstage and airier presentation
 

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Interesting.  That sounds more like the MB Quart sound I am familiar with.  The SP-1 is fantastically revealing in the mids and quite analytical.  Also, the speed is incredible... I'd love to pit this dynamic up against some orthos for curiosity's sake.
 
The 805 sounds much different than what you described the 8.300 to be.  I find the 805 to not be quite as quick as the other Quart models and carry a meatier, richer bass with it.  Makes for a fun signature, even if not ideal.
 

Yes, it's 300ohm vs a lot less. But they are very much the same, the 805 vs the 8.35. With three different pads coming up to a total of 6 different combinations, I think my favorites are the 8.35's with stocks and 805's with ovals (6050), though they are quite different. 
 
The K272HD is the cheap audiophile version, so to speak. It doesn't have a detachable cable, but the K271mkII does. I picked the 272 because I was a bit afraid of the headband mechanism on the 271 (mutes sound when taken off). Thought it might break at some point. 

I will skip the K550 altogether. AKG already has a great closed headphone in the K181 and given the price I am not convinced the price/performance ratio is worth it...

on the subject of 'sound not worth the price,' I've got something for you guys.
 
 
Maybe you've heard it before, or haven't. It's the panasonic htf600s. A 'closed' headphone that leaks a lot, isolates little, but is 'closed' nevertheless.
 
- it's the most comfortable headphone i've ever come across (Sub 200g, smallish portable phone). And you will think the same when you come across it. That's a guarantee.
- it cost's £30 here. Reportedly around $30 in the states.
- it shook the life out of me when I heard it for the first time. A few weeks ago that is. I could not believe the sound it was producing. £30. That's rrp £30. During my time at headfi, i've only had this jaw-dropping experience twice. when i got my first 'hi-fi' headphone and this time.
 
 
My point is that to a certain degree you have to really take into consideration whether the headphone isolates or doesn't, and compare within them categories. It's done with 'open' and 'closed' headphones, and should be done here as well.
 
If this panasoic was fully closed and isolating, it will never be at the £30 mark.
 
 
 

Quote:

cantscareme said:

on the subject of 'sound not worth the price,' I've got something for you guys.
 
Maybe you've heard it before, or haven't. It's the panasonic htf600s.

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Oh boy, here we go again...

Quote:

electropop said:

The K272HD is the cheap audiophile version, so to speak. It doesn't have a detachable cable, but the K271mkII does. I picked the 272 because I was a bit afraid of the headband mechanism on the 271 (mutes sound when taken off). Thought it might break at some point. 

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You paid a lot of money for the HD letters and a lack of a mute switch and detachable cable.

Quote:

rhythmdevils said:

You paid a lot of money for the HD letters and a lack of a mute switch and detachable cable.

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They have much more air in their price. I luckily was able to pull some strings... Even if I weren't, they are roughly 50eur less here in Finland than the studio version.

while remaining totally OT, the HD versions of the AKG line does have the velour pads while I think all of the studio versions have pleather, which DO have an impact on sound. I've compared my own K240S to the K242HD which should be the exact same headphone but the 242 is a little bit clearer and does not have the booming midbass of the K240S, as well as better comfort (the pleather does become sticky after a long listening session), so even though I think it's annoying that the HD-versions doesn't have detachable cables, I'd still choose them over the studio versions.
 
just my two...

Quote:

msninja said:

while remaining totally OT, the HD versions of the AKG line does have the velour pads while I think all of the studio versions have pleather, which DO have an impact on sound. I've compared my own K240S to the K242HD which should be the exact same headphone but the 242 is a little bit clearer and does not have the booming midbass of the K240S, as well as better comfort (the pleather does become sticky after a long listening session), so even though I think it's annoying that the HD-versions doesn't have detachable cables, I'd still choose them over the studio versions.
 
just my two...

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had almost all iterations of the AKG K240/2 line... and while this is totally true and the K242HD is a surprisingly great headphone (K240s WITH VELOURS included)
you can have the K240MKII quite often (depends on your country) for the same/cheaper price which has both pads and two detachable cables.
 
 

K242/272HD are effectively excellent headphones for the price but amp is required.
 
Generally in Europe, HD version are much less expensive than studio version.