I'd also hazard to say that without some judicious bass boost a headphone just can't sound as real as great loudspeakers can. Something in a headphone has to substitute for the lack of slam and moving air that you get in real life from live sound or from a good stereo system. I think Denon might have taken things just slightly too far in the bass domain, but that may be preferable to not taking things far enough (a common error in headphone design).
So, the 5000s are special because they have intelligently and musically tuned bass. But that wouldn’t be nearly enough, if the midrange weren’t equally good. But it is. The midrange on the Denons is relaxed, clear and well-balanced. In particular, Denon doesn’t roll off the upper mid-range as some other models in this class do. The result is that the 5000s sound more open and life-like than competing headphones such as the Sennheiser HD-650s.
Overall, the treble is well-balanced with the mid-range and bass. There is, however, a mid-treble edge that occasionally grates, though only slightly. It shows up less as a shift in overall tonal balance, but rather as a tendency to make sibilants and high frequency transients a little "sharp" sounding. This doesn't happen on all transients, which is what makes me believe the issue is in a pretty narrow frequency band. Some modern recordings accentuate this, so the fault isn’t entirely with Denon. Nonetheless, this tendency to make certain treble transients a little too hot is in my view the make-or-break issue that will determine whether these headphones are for you (or not).
As you might expect, very neutral-sounding headphone amplifiers (such as the Luxman and PS Audio units that I had on hand for this review) tend to expose both the Denon’s mid-treble strengths and weaknesses. It is possible, however, that different and less neutral amps could optimize the Denon’s sound by softening treble transients to some degree.
To keep things in perspective, bear in mind that the AH-D5000 is all about serving up a sound characterized by rich and vivid tonal colors. The minor sonic excesses I’ve described above may well be the price you pay to enjoy the concommitant richness and vividness—a tradeoff many listeners will, I suspect, happily embrace.
The other issue that I’d raise is that the 5000s have a slight tendency to divide music into Bass/Midrange/Treble segments. Each region sounds good (mostly), but overall this presentation isn’t entirely natural. Classical lovers may notice this more than lovers of other musical styles.
The 5000s present an interesting contrast to the Sennheiser HD-800s, which I also review in this issue. The Sennheiser's major in naturalness (errors don't call attention to themselves; relaxed and smooth), but have some subtractive errors that mean they aren't the most vivid (fresh; intense; alive) headphones on the market. The HD-800s are good in the vividness department, but not great.The Denon's, on the other hand, are quite vivid, though at the expense of naturalness at times. The Denon's colorations are small enough that you would say they are good but not great on the naturalness scale.
On Mary Black’s song “Trying to Get the Balance Right”, from By the Time It Gets Dark [Gift Horse], Mary’s voice is very clear. The accompanying acoustic guitar is plucked emphatically on the initial beats of the chorus, and the treble edge I mention above results in the guitar sounding a little more metallic than it should. You can hear a similar, slightly unnatural effect on Alison Krauss and Union Station’s song “Maybe” [Alison Krauss & Union Station – Live, Rounder/UMGD]. The 5000s handle the voices transparently, but the chorus of that song has a multi-part harmony where the difference in voices yields too much overtone ringing.
By contrast, though, I found that on Paavo Jarvi’s version of the Beethoven 3rd Symphony [RCA Red Seal] the Denon’s had a very listenable treble presentation with good clarity. The cellos were, however, under-emphasized a bit. In this case one might say the sound was a little cool, though thanks to the strong bottom end, the sound isn’t thin.
The AH-D5000 ear cups are soft and the clamping force is very low. As a result they are comfortable for long periods (they don’t aggravate pressure points), although they are slightly heavy so that the headband occasionally needs to be shifted.