The Luscious Denon AH-D2000, AH-D5000, and AH-D7000
I've been listening to this fine lineup of Denon headphones for a long, long time. They've always struck me as really good, and a bit weird sounding...loose-ish or something. But yummy and lush, too! I've got a personal pair of D5000 and I like them a lot.
I discovered some new stuff in the current Dx000 models as I wrote this review and I'm excited to tell you it's all good news. But to tell the story properly we must cover some basic information first.
The overall design of these headphones are nearly identical, sharing many parts in common. But there are some differences from one to the next.
Driver - All three headphones use a 50mm diameter microfiber diaphragm. The drivers in the AH-D2000 ($349) and AH-D5000 ($699) are identical (I found the manufacturing part number markings stamped on the rear of the drivers to be the same); the driver in the AH-D7000 ($999) has an 11% stronger magnet making it slightly more efficient (108dB/mW vs. 106dB/mW). Denon marketing materials say the driver has a "free edge," sorry, not sure what this means--there is a flexible clear surround attaching the outside edge of the diaphragm to the driver housing
Housings - The D2000 housing is plastic, and has some damping material adhered to the rear of the cup, and a ring of fibrous acoustic wadding. The D5000 and D7000 use mahogany wood ear cups and are bare. The D5000 housing has a satin finish and a printed logo (which can wear off rather easily). The D7000 housing has a slightly larger internal volume, and has a gloss lacquer finish with an inlaid metal logo.
Driver Plate - This is a black plastic assembly that holds the driver and provides the mechanical means to assemble the housing and frame together. The driver plate on the D5000 and D7000 are identical; the D2000 plate has bosses on the rear to properly space the plate and housing. Mark Lawton (of Lawton Audio, a company that specializes in modifying Denon Dx000 headphones) claims the D2000 driver plate is slightly less rigid than the others.
Magnesium Frame - This is the metal ring around the headphone to which the headphone gimbals attach. This is a molded magnesium part that is painted silver on the D2000, and a lightly tinted gold color on the D5000 and D7000. This part appears identical on the D5000 and D7000, and is very slightly different on the D2000--it's missing the small detent bumps on the rear of the part which act to allow the ear pad to "snap" into place. I'll come back to this a bit later.
Ear Pad - All three ear pads are dimensionally identical. The pads on the D5000 and D7000 are identical; product literature states that the D7000 ear pads are leather...they are not. I've taken one apart before and it is some sort of synthetic material, possibly Ultraleather. The D2000 earpads appear to use a slightly inferior grade of synthetic leather, but still seems pretty nice to me.
Headband Assembly - All metal parts for the three headphones appear to be the same. The cast magnesium parts are all painted, and like the magnesium frame above, the D5000 and D7000 parts have a slight gold tint; the D2000 is silver with a slightly heavier visual texture. Like the ear pads above, the synthetic leather headband cover of the D5000 and D7000 appear to be of a slightly better grade than the D2000.
Cables - Both the D5000 and D7000 use identical cable with 7N oxygen-free copper (99.99999%) conductors, but the fabric sheath on the D7000 is significantly thicker. The D2000 uses lower grade OFC conductors and is also fabric sheathed. The D7000 cable is terminated with a 1/4" plug, the D5000 and D2000 are 1/8" plugs and 1/8" to 1/4" adapters are included. All plugs have brushed aluminum bodies and gold plated connectors and all cables are 3 meters long.
It seems to me that we're seeing in the various differences between models a serious effort to carefully pinch pennies on the D2000; build a solid performer with the D5000; and guild the lily with the D7000.
Isolation, Sealed or Open?
The Denon AH-Dx000 headphones are full-sized, around-the-ear (circumaural) headphones. They have a closed back--meaning there is no opening in the rear of the housing behind the driver to let the sound escape the headphones easily--but they are not sealed headphones, even though they are commonly thought of and characterized as such. I read all the Denon literature on these cans, and nowhere did they claim them to be sealed. Denon uses the term "Acoustic Optimizer" to describe the acoustic principle at work in these headphones. Bah, marketing blurbage!
In order to have the lovely uninterrupted wood housings (though the D2000 is plastic) of these headphones--which does give them a simple and elegant look--the acoustic engineers had to deal with the potential of resonances developing in the chamber behind the driver. This is a very real problem in sealed back designs, and is what makes sealed headphone performance generally inferior to open headphone designs. In the case of the Dx000 headphones, the engineers developed an acoustic labyrinth of channels, damped windows, and vents which are designed to inhibit and control resonance and response. (All well designed headphones have these elements, but because of the closed back of these headphones this design appears to be somewhat more complex than most.) The external vent of this design is a thin gap around the entire ear piece between the magnesium frame and ear cup housing.
While this design does a good job of controlling the sound of these cans, it also provides ample opportunity for sound to escape from the headphones, and for external sounds to enter them. The Dx000 do not isolate very well at all, and people close to you will be able to hear your music. I think they should be considered a semi-open design. Unfortunately, I don't have a category for this type of headphone here at InnerFidelity, and because they do provide somewhat more isolation than open cans, and because so many people consider them a sealed headphone, I will continue to categorize them as such. I'll make a note here that the Phillips L1 is also of similar semi-open design, and I have placed them in the open category here at InnerFidelity.
Comfort, Build, and Style
I find the Dx000 headphones to be very comfortable. Caliper pressure on the ears is modest, and the earpads are plush. They're about as good as it gets for long listening sessions. Build quality is excellent, but I would characterize these headphones as somewhat delicate. I do not recommend them for portable applications where wear and tear may be damaging to the fine finish of these cans. I've also noticed over time that the screw holding the bail to the headband assembly is prone to backing out causing the headphones to rattle a bit and sometimes falling apart. The screw is on the underside of the bail, and the earpieces must be disassembled in order to tighten it. Despite these observations, I think the look of these headphones is terrific, and feel that the developers of these headphones have made some very good choices in their design.
Speaking of Developers
These headphones are actually designed and manufactured by Foster in Japan--parent company of Fostex, who also make the famous Fostex T50RP which is a favorite among DIY headphone modification enthusiasts. Foster is a terrific headphone maker, and I think Denon has chosen their supplier very wisely. You can see these headphones on this Foster page, part numbers 443742 and 448498.
I think one of the marks of a great manufacturer and a long-lived product is the willingness of the manufacturer to glean feedback from customers and make improvements to a product over time. While this type of work is assumed by the public to occur with car models and car manufacturers, which make changes year to year, it is more common for consumer electronics manufacturers to either change the model number as a product is improved, or to simply say nothing at all as changes occur. The latter, evidently, is the case with the AH-Dx000. These changes will no doubt cause angst among the Denon faithful.
All you headphone enthusiasts out there need to push the reset button on what you think you know about these fine Denon cans because they've changed. Let's have a look...