Another AKG homie here. AKG are my favorite brand for headphones and I also really like their mics, especailly the cheaper ones which are amazing for the price.
My AKGs:
AKG K404
AKG K142HD
AKG K240 Sextett - Actually Saba H200, which was a headphone built by AKG for Saba. It's a 240 sextett with a different headband and caseback. Same baffle, driver, baffle damping, cable, connector, gimbal, pads, etc...
My impressions of the above:
K404 - Very gutsy bass for their size, treble on the brighter side with a slight harshness on certain songs, slightly recessed mids but smooth. Closed sound a decent stage. Good separation as well. Very portable, fairly comfortable, decent isolation, easy to drive from SGS3. I did a simple damping mod by adding a bit of cotton inside the cans. Helps control the bass, brings out the mids and smooths the treble. Definitely a killer set of portable cans for the price.
K142HD - Very neutral and natural, well balanced. Some say they have wimpy bass but I have to disagree. Sure, they are not exactly bass heavy, but they will kick and punch if you ask them nicely. Also the bass is very very well controlled and defined. Smooth mids. Highs are excellent in my opinion. Slightly laid back but very detailed. Slight sibilance occasionally but nothing serious. Not the biggest stage but excellent separation. Cymbals sound amazing with these cans.Very smooth and easy to listen to, yet still detailed. Also won't cause any fatigue. Comfort wise, they pinch way too hard when new but I stretched mine over their box every night for about a week and now they're one of the most comfortable headphones I have, you just have to get used to eachother... They provide very little isolation and leak a fair bit. But they are monitoring headphones after all. Build quality is great, they're solid but lightweight. I've been carrying mine in my backpack for a year now and they have yet to show any signs of wear and tear. One of the best bang for the buck headphones currently IMHO, nothing really wrong with them at all.
K240 LP (H200) Sextett - When I picked these up at the flea market, I was super excited because I've heard so much good about them and never actually thought I'd have a chance to give them a listen, let alone own a pair. I'll start off by saying that they're well built and are certainly exceptionally good for their time. Sadly, other than that, I really can't see what all the hype is about. They're not exactly bad, but they're really not what I was expecting. They have a weird bass response. On some songs, they seem very bass heavy, on other song they have no bass whatsoever. Bass doesn't punch at all, but is just a weird, sloppy mess. Mids are supposed to be the strongest point of these cans but I don't think they're anything special. Highs are quite detailed and nicely layered but sometimes harsh and quite sibilant, especially at louder volumes. Sound stage seems endless, but the instruments are smeared all over the place on more complex passages, especially in rock. Vocals sound boring, especially low male vocals. They lack serious body and warmth and overall I think they sound just mediocre. I did add some damping inside that seemed to make a bit of difference, but not enough for me to love them. I also find them VERY uncomfortable, the plastic grills push hard against your ears and the leather pads get hot and sweaty fairly quick.
For an example, I used Radiohead's Creep as a comparison track. K142HDs give the whole song a lower, depressive sound which is the point of the song in question. They also bring out the ride and hi-hats quite a bit more. Electric guitars have a more grungy feel with these cans, while the K240 gives the guitar a more detailed, distorted sound which is good actually. Vocals sound very realistic on the K142HDs.
The K142s can also bring out flaws in many songs. For an example, Ram Jam's Black Betty's drums. You can really hear that the floor tom is not very EQ'd and has plenty of resonance and overtone. Also bass drum kicks on many songs have a certain resonance to them from the actual drum itself echoing. I know this, because Tyler knows this. Oh sorry, I forgot rule no. 1
Actually I know this because I'm a drummer and I have to mic and EQ my set.
Why do I like the K142HD more? Because I like balance, natural sound, detail, a full sound.
What makes the difference, tho? Is it the Varimotion drivers, the metal enclosure, the velour pads, the high quality OFC cable, the damping, the tuning, the baffle or all that combined?
The answer is simple: I don't know. I'll give them velour pads, foam damping in front of the drivers, more and better damping inside the enclosure, maybe open the back up more, cut bigger holes into the grill and re-cable them. Maybe. If I have the time and resources. But as of now, I can't find a single reason to use them.
I will definitely keep buying AKG, tho. My next goal is to score a pair of K701 or something in that league.