Quote:
Quincy uses those headphones because he gets paid to be seen wearing them.
This.
As noted, your two choices here are between two very different phones with two different needs. The D2000 is a great phone that is easy to drive. It's a little colored and warm, but wonderfully punchy, detailed, comfortable, and performs fantastically with a wide variety of music. Midrange and low end is nice and full, and the top end never loses it's polish or sounds thin or strident. They are a bit heavy, but the ear pads are very comfortable. These are closed phones, but they are not the most isolating...not much of a problem for the listener, but they leak a lot of sound. Also, being closed, they give a nice up close and personal presentation while still maintaining a nice wide soundstage.
The AKG's in comparison are much more dry, sterile, and bright. They excel with jazz, brass, vocals, and other "boring" stuff like that (kidding). They lack somewhat in the low end impact, however the bass is very nuanced and detailed. At the top, the highs are bright and sparkling, but the overall presentation, to some, is just too analytical. The open design presents a nice open soundstage, and the imaging and separation of instruments are amazing...really pinpoint placement.
As far as needing amplification, they both will benefit from a quality amp, but the Denons are a lot more forgiving in this area. They can sound a little muddy or bloated without one, and an amp will help get a firmer grip on the bass. The AKG's on the other hand absolutely need a amp to not sound awful. Don't let the low impedance fool you...they will sound flat, dry, will lack dynamics and image, and sound very harsh without one.
Regarding burn-in/break-in: this comes down to a matter of belief in regards to componentry, however I feel that it IS a factor in headphone sound. Yes, they will both benefit immensely from an extended break-in period. The Denons sound nice out of the box, but really firm up their sound and clean up their imaging after 50-100 hours or so. The AKGs sound almost completely lacking in bass, and are slightly sibilant at the top, and require a LOT longer to break in. 100 hours or so gets them smoothed out and gets some bottom end to them, but they continue to improve up to around 200-250 hours or so. As mentioned, there is more of a "getting used to the sound" factor at play here than much in the way of actual physical change...unless you really listen for changes you won't notice them over time, but try listening to a pair of out-of-the-box vs. a 500 hour pair, and you WILL find them quite different.
With these two phones, it really isn't a matter of which one sounds better...they are both excellent performers, and won't fail you in terms of performance, but they DO sound very very different, and you should go with which ever sound signature you like better. Also, amplification should be a prime concern...if you don't want to get a dedicated headphone amp then you'll really need to rethink the AKGs.
Anyway, hope that helps...for reference, I'm a Sennheiser kinda guy, and I prefer warmer, lusher sound, hence I liked the sound of the Denons better and the D2000 was a nice closed alternative to compliment the HD650. They are a fun phone, very lively and musical, with a deep bass response and amazing musicality. The AKGs sound great, but they didn't perform as well as I'd like with my musical tastes, but if you are a fan of uncompromising details, analytical presentation, and critical listening, they are the way to go. Good luck!
