malveaux said:

 
The K240 MKII and K271 MKII are quite similar. The 240 is semi-open. The 271 is closed, sealed. The 240 is great for vocals, and is good for recording, because you can hear things outside (like yourself) which is important for some recording. The 271 is closed, so has isolation, and is better for recording instruments while listening to something that won't be captured on a microphone. As casual musical listening headphones (instead of being used for production), they're good, but not stellar. Again the K240 is great with mids and presents vocals/instruments superbly but is not as strong in extremely low end bass response or high treble response. The 271 has a little better bass handling and is similar, but not quite as superb at mids, but provides isolation. It's a flavor thing.
 
Very best,

Click to expand...

kirudub said:

My 2 cents as a musician regarding the K550s... since they rely on a total seal to perform as intended, if you or your mate wears glasses, the K550s might not work.
 
I was unable to audition them and bought them on reviews (and the fact that they were sealed so I could use them while recording vocals).
 
Unfortunately, even though they sounded good, they didn't work with my glasses, and I re-boxed them for return after 10 minutes of wear. 

Click to expand...

tdockweiler said:

You should add the DJ100 back to the list. I've owned most of all those headphones listed except for the Sennheisers and K271. I do have the K240 though.
 
The Dj100 with his setup will be OK i'm sure. It's not excessively power hungry at all, but is more picky. It can sound bad with the wrong equipment. For example, it's low mids were too forward on the Fiio E10 and rather muffled sounding. That's not how it should sound. It's best with very transparent gear.
 
I find it flatter than the K240 Studio. The K240 Studio (And SRH-840) actually has a mid-bass hump, but it seems to not be as noticeable after awhile on the k240. No clue why. The K240 Studio (IMO) is harder to drive than the Dj100. The K240 Studio doesn't get loud enough from portable devices for me sometimes. I haven't used mine in maybe a year though. K240 Studio is very underrated.
 
KRK KNS-6400 is pretty flat, but it does sound kind of lean, especially in comparison to the KRK KNS-8400, DJ100 and K240 Studio. The DJ100 with proper seal and decent enough amp is very full sounding, but not like an HD-650 unless you do a pad swap.
 
It does have slightly forward upper mids, but not as forward as a Grado. The mids of my 598 actually sound more forward. The DJ100 has slightly more treble than your 598, but less than a Q701.
 
DJ100 has more present low bass than the K240 studio, 598, Q701 and my HD-650. It has slightly above neutral bass. No mid-bass hump that people seem to love.
 
The KRK KNS-6400 sounds bass light but it has good low bass extension. The 8400 is fuller sounding than the 6400 and seems a little bassier. Both are quite treble happy, so that's one reason I prefer the DJ100 to them.
 
You can even upgrade the DJ100 with M50 pads or even Velours.
 
I'm also a fan of the SRH-840 but sold it due to comfort and have been using the DJ100 ever since.

Click to expand...

amigomatt said:

Thank you, tdock, this is all great stuff and nice to know it's first-hand experience.  Damn though!  Decisions, decisions!  The Koss are at a really good price here (£58), but despite Kirudubs warning about the seal/clamping/bighead issues with the K550s, I'm nearly at the end of the appreciation thread and it seems to be not as problematic as first seemed.  Obviously, if one can't get a good seal, that's bad, but most people there have no issues, or have easily sorted it out and are raving about these cans as being equal or better then DT880s, K702s.  Some have said they are a decent step up from the SRH-840s you mentioned too.  They look fabulous and the build quality seems very high.  How would the K550s compare to the DJ100s?   I mean, they are obviously more expensive, but is there much in it?  Are the Koss in that ballpark?

Click to expand...

tdockweiler said:

I didn't like the K550. It had good bass, but rather anemic and thin mids to my ears. Makes no sense. Mine didn't sound that clear.  I was OK with the treble. I think my source at the time was the HRT MSII and Headroom Micro. The MSII is kind of warm too, but the Micro isn't.  I think I got rid of them immediately. I can understand some may like them. Maybe I was too quick to judge them. Maybe my comments are off the usual consensus. Who knows. Overall I found the K550 rather dull and lifeless. And no I don't like a very colored sound

 
I felt the SRH-940 and SRH-840 were better, but then again I'm no musician. I did feel the DJ100 sounded better then the Shures, but would take any of the KRKs over the SRH-940 I think. SRH-940 I liked enough to buy if it was $200 or so. Maybe sometime.
 
The M50 also isn't as bad as everyone seems to say lately. The latest white boxed version isn't that bassy. I don't like it's mids though. I'd take it over the K550 though. Even the K240 Studio is better than the K550 IMO.
 
Based on memory the K550 has more treble than the DJ100, leaner mids and maybe a little more bass. I honestly didn't do any A/B comparisons. I got them within a week of release and it was the biggest disappointment in a headphone I had for quite awhile. I think I paid $300 and my Q701 was way better and only cost me $235.
 
You could try to find a used Q701 and get a cheap amp for less than the K550 maybe..not sure of the current price of the K550 in your area. The O2, Magni and E9 are enough for the Q701. Here in the USA you can often score a Fiio E9 for $65USD. It loves the Q701!

Click to expand...