World's Best Headphones Review: The Denon D7000, D5000, and D2000.

[caption id="attachment_1281" align="alignright" width="300" caption="The surprisingly good sounding line-up of high-end Denon sealed cans: D7000, D5000, and D2000."][/caption] For a long time the sound quality available with closed headphones was quite poor. Then, a few years ago, Denon appeared with not one, or two, but a whole line of sealed headphones that smoked the competition at virtually every price point. At the top of their line are three of the world's best sealed headphones. Construction The Denon AH-D2000, AH-D5000, and AH-D7000 are all very similar full-size, sealed headphones.  The family uses the same design throughout, with common earpads, cast magnesium fittings, baffle plate, and variations of similar housings, drivers, cable, and finishes. [caption id="attachment_1285" align="alignnone" width="467" caption="This exploded view shows the D7000, but all three headphones are essentially the same design with materials and driver variations."][/caption] The overall execution of the design is very good throughout the line; these are nicely finished and very good looking headphones. The cast magnesium hardware components  function well and are finished tastefully. However, I would also consider these headphones somewhat delicate and fragile. Fine for around the house, but audio professionals will have to take a bit of extra care in use. [caption id="attachment_1288" align="alignleft" width="300" caption="Here I poke the reverse side of the "leather" out to show that it has a backing indicating it is a synthetic leather."][/caption] The earpads used on all three models are wonderfully comfortable, and are fashioned in soft glove leather ... or so it seems.  It does say "leather" in a couple of places on Denon's illustrations and literature PDFs, but I'd read on Head-Fi that the pads were synthetic. You can't tell by looking at them, they look and feel very real, but I just had to know for sure, so I broke out my sewing kit and had a look. Sure enough, they are some sort of synthetic leather; maybe the nicest synthetic leather I've seen, but still ... pleather, not leather.  Each pad is attached to a mounting plate with a flap of material that flips over its edge. The mounting plate has four nubs which insert and twist to lock them into the magnesium frame of the housing making it very simple remove and replace the earpads. One note here: the earpad slides around very easily on its mounting plate, so the earpads are easily rotated around without the mounting plate beneath moving. Removing the mounting plate requires a counter-clockwise rotation of about a half inch at the perimeter; you may have to grip the outside edge of the earpad very firmly in order to rotate the mounting plate for removal. The stock cables on the D5000 and D7000 are excellent with conductors that are 99.99999% oxygen-free copper. The conductors in the cable on the D2000 is copper of lesser, but still good quality. I'm generally in the middle of the road when it comes to cables, thinking they make a difference sometimes, but often not one big enough to warrant the price. When it comes to headphone and speaker cable, however, I find the differences can be substantial. I tend to think the improved cable is likely a strong contributor to the significant improvement with the step up the D5000 or D7000. [caption id="attachment_1290" align="alignright" width="300" caption="L to R: The D7000, D5000, and D2000 housing covers."][/caption] While the housings on all three model are similar in shape, the materials and interior design vary somewhat. The D2000 housing is molded of a plastic with metal filler to increase density and rigidity, it also includes a little packing and damping material attached to the inside that the other two do not have. The D5000 and D7000 earcups are machined out of mahogany. [caption id="attachment_1291" align="alignleft" width="300" caption="The D7000 (left) has a slightly deeper and better finished housing then the D5000 (right)."][/caption] The D5000 has slightly less material removed from within the cup, and is slightly rougher and not painted; the D7000 is roomier in the cup and better finished. [caption id="attachment_1293" align="alignright" width="300" caption="The free-edge, microfiber diaphragm surrounded by the baffle plate called the "acoustic optimizer" and Denon's literature."][/caption] Driver diaphragms in all three models are made from what Denon terms "free-edge, micro fiber" construction. Denon marketing copy claims, "The size of the Microfibers is approximately 1/100 that of natural cellulose used in ordinary diaphragms, and with this density, transmission rates are increased.  In comparison, Microfiber diaphragms are (x20,000) and natural cellulose fiber diaphragms are (x150)" which doesn't really give a complete picture --- unfortunately, I was unable to find any deeper information. My experience with headphones leads me to believe that the drivers (actually made by Foster, parent company of Fostex) are quite good. The drivers in the D2000 and D5000 appear quite similar and share some numbers stamped on the rear. The D7000 drivers have a stronger neodymium magnet; I did lay a small tweeker screwdriver across the back of the driver assembly and the D7000 magnetic force was markedly stronger than that the other two drivers. Sound Quality [caption id="" align="alignright" width="298" caption="Frequency response data for all three headphones show surprising linearity from mid-bass to mid-range."][/caption]As I mentioned up front, the sound quality of these headphones is very good; in general all three headphones are both quick and rich sounding with a slightly "up front" presentation. The technical performance of these headphones are among the best we've ever measured. The D2000 is actually a very good sounding headphone, among the best at its price point.  It is slightly dryer sounding than the other two Denons, though I would not say bright or harsh at all; the worst that can be said is they may sound slightly grainy. The mids are very slightly recessed; the bass is tight, punch, and slightly but tastefully accentuated. The D5000 takes all the goodness of the D2000 and refines it into even goodlier goodness. Audio professionals should make special note of these cans as their measured performance is simply outstanding, and the overall sound is both accurate and liquid --- an unusual and welcome sounding can. I've recently recommended the Sennheiser HD 800 as an ideal tool for the serious audio professional and enthusiast, but at half the price; nearly as good performance; and in a sealed headphone to block out a little outside noise, the D5000 is likely to end up as a very useful tool for many professionals and audiophiles alike. [caption id="" align="alignleft" width="298" caption="The 50Hz square wave response of the D7000 (blue) is not as linear as the other two, and drops below zero indicating less damping of lows."][/caption]The D7000 makes some gains in the highs and mids with a lusher, smoother, and more organic sound while improving in detail articulation as well---very nice.  Unfortunately, they also are a little looser and less controlled sounding in the lows; this can be seen in the 50Hz square wave measurement with the trailing edge of the waveform crossing the central zero axis. Because all the baffle plates look identical, I assume this has something to do with the slightly larger internal volume of the housing. Though all these cans are sealed, it's worth noting that they don't isolate very well. Using these headphones on an airplane or train is not recommended. I suspect this is because they don't have a very high clamping force on your head --- which help make them a very comfortable headphone, but also makes them a little unstable on your head (not a very good active or exercise headphone), and prevents them from forming a tight seal to isolate you well from outside noise. Modifications Having gained a LOT of attention by the headphone enthusiast community a number of modifications have become available. [caption id="attachment_1300" align="alignleft" width="300" caption="The JMoney pad (right) is significantly thicker than the stock pad (left)."][/caption] I mentioned previously a somewhat "up front" presentation meaning the Denons give the impression your sitting in the first row or close to the musicians. Some folks like this as it give more heft to vocals and a sense of intimacy, but it also reduces the depth of image and makes the sound less layered. To address this issue for those who like a more laid back sound, JMoney makes some very nice lambskin earpads.  The earpads are significantly thicker than the stock pads, moving the drivers slightly farther from your ears and providing a more laidback sound without otherwise affecting the very good tonal balance. The additional thickness of these earpads also provides a bit more clamping force which in turn provides a little more isolation from outside noise and stability on the head. The Denon AH-D7000 and AH-D5000 are also available from HeadRoom re-cabled for balanced operation with HeadRoom's proprietary Cardas FatPipe cable for use with our balanced headphone amplifiers.  Custom lengths are available. Please visit HeadRoom’s website to purchase your Denon AH-D7000, AH-D5000, or AH-D2000 with our Best Price Guarantee. For further reading on these headphones check out these threads at Head-Fi: Denon D5000, D7000 Comments D7000 instead of D5000, is it worth it? MarkL mod made easy!