AKG K451 High-Performance Foldable Mini Headset (Black)

I bought these through an internet auction site for a very reasonable fee, so that will affect my view on these slightly as I've not paid RRP.
 
I am more than happy with the quality of sound that these put out from my iPhone. The soundstage picks out the individual instruments and puts them together very well with a good measure of bass (which was my main requirement for purchase). I have a varied taste in music, but is mostly rock/alternative and it plays these very effectively with even the acoustic versions coming through with great clarity. I have trained as a sound engineer, and have a good audible range in my hearing so was expecting to be able to pick out issues, but have been very pleasantly surprised.
 
I do not have a $500 version to compare this to as yet, so I may yet amend my view if/when I add to my collection, but I am more than happy with this purchase.

Considering the poor review level here I felt I had to post a review:
 
I spent some time checking reviews of these AKG K451 headphones, and found conflicting comments. What I can do is confirm that What Hifi (who awarded these a best buy in 2014) were right, these are excellent headphones even straight out of the box with no burn in time. My requirements were for a compact set of 'on-ear' folding headphones. This obviously means certain compromises need to be made, so the 451s will not match up to larger more expensive headphones, but for £50 are excellent performers. Build quality feels good and though I have only had them a few days, don't feel that anything is likely to break. On-ear pressure is quite firm and for extended listening sessions can start to become uncomfortable, but all headphones do after a while anyway. There is minimal sound leakage as long as they are correctly positioned on your ears. Very pleased I went with these.
 
I do prefer bass heavy music and find very 'bright' headphones fatiguing to use, so prefer the softer sound these have. The treble does lack a little sparkle, but for their size and cost, these are very enjoyable headphones.

I joined head-fi specificaly to post this review....

 

First - my credentials as a headphone user (as far as they go). I've been into hi-fi for 3 decades, and consider myself a reasonably discerning and critical listener. I'm currently using some byerdanmic p50t's, a pair of koss prota pros :-D and some sound magic e10 in-ears for the bus .

Disclaimer - I've also posted more or less the same review below on the What Hi-Fi site. Everyone needs to be warned about these lame headphones! We have to save ourselves from the pernicious mediocrity and terrible superficiality they represent!

I honestly can't understand how these headphones won any kind of award, let alone the What Hi-Fi best product (headphone) award 2012.

I just picked up a pair from Richer Sounds for £50, a bargin i thought given the list price (I'm assuming they are not fakes, given the vendor). I bought them as an alternative to my sound magic e10 in-ears, partly becuase i'm fed up of stuffing things into my ears in the office every day, and partly becuase i wanted something a bit more capable of reporudcing the subtle low end in some of the stuff i listen to most (electronic mostly), whilst still delivering decently textured mid and highs.

Perhaps my expectations were unrealistic, but the AK451's are sadly far from an improvement...

The K451's are (very) muddy in the mid and high's, far too bass heavy, boxy and echoic, present a cramped-to-the-point-of-claustrophobia sound stage about as big as a postage stamp and are nothing even close to transparent or detailed. My £25 koss porta pros that make these seem over priced. My (admitadly much more expensive) Bayerdymanic p50t's make these look just plain silly.

I'm hopping that the rumor of them improving with extensive burn in is correct rather than just some sort of desperate self-confirming rationalisation on the part of many a disapointed buyer. I'm going to try them again after running white noise through them for 48 hours. They'll have to improve considerably if they are not to end up on ebay, or in the bin...

Perhaps they are terribly subject to batch variation, or they have somehow changed the drivers since this review. This can be the only explanation for such an apparently misleading award? Perhaps one for WHF to persue with AKG? :-/

UPDATE: I just some comparison listening between theses and the 5 other pairs of headphones i own. No amount of burn it will improve these to an acceptable level - they're awful. I'm returning them.

 
 

I bought these about 3 weeks ago as a to-go pair with my QLS QA350.  I should preface by saying I'm not particularly experienced with audiophile gear.  These would be my first considered purchase in the reasonable-quality area after becoming fed up with lousy fidelity from mainstream mp3 crapola.
 
I bought the QLS and the AKG's simultaneously, so I'm not entirely sure which exactly the qualities emanate from, but I'll hazard a guess.
 
SOUND
First things first. The initial characteristic that leapt out at me the moment I tried these was smooth! I don't know what the technical underlying basis for this characteristic is but, compared to what I've listened to in the past, these just sound blissfully smooth (if someone can tell me the basis, i'd be interested).  For an analogy, it brings to mind the feel of that matt silicone rubber that's popular as cases for stuff these days - not slippery per se, but very smooth. Very pleasant to listen to.
 
In terms of frequency response, the midrange is there.  Not prominent but adequate. Likewise for the high end - there's enough detail there for the price.  I'm not hearing ultra-high end but that could well be my ears.  There's an agreeable level of detail and clarity (and I think they can be had for considerably less than what I paid).
 
But then there's the bass. That's definitely there too - in spades.  It's reasonably well defined and the extension is good especially considering these are compacts, but there's a hell of a hump.  It's not that the sound is bad, or that I don't like bass. I do, but it's disproportionate. It's like there's two drivers and the bass one is driven at twice the level of the mid/highs.  
 
I assume this is AKG pandering to the masses. They are positioned as i-pox accessories after all.  Annoying because this is exactly the kind of thing I wanted to avoid by buying reasonably good stuff.
 
COMFORT
Moving on from sound, comfort is fine.  I probably have about an average-sized guy's head and they feel good.  Probably not for endless hours though - they are on-ears.  Pressure is moderate without being excessive.  The earpads are pleather-whatever and although they never really seem to feel like they're in the right place, moving them around doesn't seem to make any difference to the sound.  
 
They are hot though. Forget about wearing them for exercising in warm weather.  I wore them for 5 minutes on my stationary cycle and took them off.  Not unique to this device I'm sure.
 
BUILD
seems reasonably good quality, commensurate with the price.  I wouldn't expect them to break with careful use.
 
ISOLATION
none.  I wore these to the gym (sounds like I'm a fitness junkie - i'm not!) and the mixture of the rather loud music playing in the gym and the sound coming from the phones rendered both unlistenable so I gave up and put them away.  Again, probably not unique to these phones.
 
ACCESSORIES
comes with a nice moulded flexible zip box, a plain cord and a cord with i-phone controls.  I'm not obsessive enough to pack them in the box after each use, but it'll be handy when I flog them on ebay.
 
SUMMARY
sound nice and I enjoy listening to them despite the BASS, but I'll be getting rid of them for that reason.  I'm already eyeing up a set of Beyerdynamic DT1350's.