MrSpeakers Alpha Dog headphones ($599) are the world's first 3D printed production headphones and as such certainly deserve a place in the Guinness Book of World Records. But unlike a counting horse or a talking cat, the MrSpeakers Alpha Dog has additional redeeming social value: it attempts to deliver a closed-cup, isolating headphone that sounds as open and sonically unencumbered as an open-air headphone. In the past, many headphone manufacturers have tried to achieve this sonic goal, and few have succeeded. Perhaps the addition of 3D printing technology can bring this ideal to full fruition. Let's find out.
The Alpha Dog headphones are an around-the-ear closed-cup design that utilizes a complete seal around the ears to deliver maximum physical isolation. The Alpha Dog's basic driver components are the same as those of the Fostex T50RP headphone, but the driver is completely rebuilt with modifications by MrSpeakers. The stock Fostex RP driver employs a diaphragm material made of foil-etched polyimide film that is formed in a special zigzag pattern. This zigzag foil pattern reduces frequency peaks, especially in upper ranges, when compared with similar drivers using a straight patterned foil. The Fostex RP driver also employs neodymium magnets that deliver three times the flux density of conventional magnet designs. The original driver's specifications claim a frequency response of 15 Hz to 35 kHz with a maximum input of 3000 mW and 50-ohm impedance.
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The Alpha Dog also uses a Fostex headband and cup attachment arms, but the cups themselves, the cables, the connecting hardware, and the earpads are all unique MrSpeakers designs. When compared with a Fostex T50RP headphone, it's easy to see why the Alpha Dog costs five times more - its overall fit and finish is much higher in materials and construction quality than the T50RP. The Alpha Dog's ear cups have a rich, dark, metallic burgundy finish, while the headband, ear cushions, and most of the hardware are professional black.
Another unique feature in the Alpha Dog headphones design is its Very-Bass bass adjustment screw, which alters the inner volume of the Alpha Dog's enclosure and in turn changes the overall bass output level of the Alpha Dog. Although this setting is user-adjustable, MrSpeakers does not recommend that end users arbitrarily fiddle with the factory settings. The screw is first and foremost a production-line adjustment that makes it possible for MrSpeakers to dial in the harmonic balance to spec. Of course, nothing is stopping an end user from changing the settings but, if they get too far out of whack, the headphones could require a return to MrSpeakers for recalibration, which can be done for a "tuning fee" of $29.95.
The Alpha Dog comes with a very nice metal headphone stand. I liked the stand so much that I enquired as to whether MrSpeakers had any plans to make it available as a separate, purchasable accessory. Unfortunately, at the present time it will only be available with the Alpha Dog. My only quibble with the stand is that, if the Alpha Dog cable is attached (which is how most folks use their headphones), the stand isn't quite high enough to keep the cans from sliding off due to the angle and weight of the cable. I used a two-inch piece of closed cell foam placed on the top of the stand to raise the headphones up so the cable would clear the bottom of the stand. While the MrSpeakers website recommends this solution for using the stand with the cable attached to the Alpha Dog, it would be better if a foam riser were included with the headphones.
The Alpha Dog's earpads deserve special attention. They are large, soft, easily removable, and designed to completely envelop your ears. I suppose if you had exceptionally large ears, you might find their inner space constricting, but I found that not only did they completely surround my ears, but I also had some flexibility in their placement. Moving the earpads position will have an effect on the sound, both in the harmonic balance and overall clarity, so I recommend that prospective owners try different fittings until they find one that best suits their tastes.
I wear glasses. There are many headphones that I like very much, but they require that I remove my glasses so that they can make a better, more complete seal around my ears. The Alpha Dog headphones, while more comfortable sans eyeglasses, still make a good seal even with glasses on, due to their thick, soft, compliant earpads.
Unlike many earphones that rely on a single cable connection point (usually on the left side), the Alpha Dog headphones have dual connectors, one on each enclosure. For some users, this dual connection scheme may be cumbersome, but it offers one major advantage over single connection methods: you can switch the left and right channels by changing the cable connections. I occasionally come across recordings with channels reversed, and switching the cable on the Alpha Dog is far quicker and easier than rooting around the back of my preamp or DAC to reverse the cables.
The Alpha Dog can be used with either a standard single-ended termination cable or a balanced termination cable. Switching from one cable to another shouldn't take more than a couple of seconds, due to the Alpha Dog's well-designed connectors. The review pair came with the single-ended cable. I used the Alpha Dog headphones with a variety of sources, from the diminutive portable Astell & Kern AK100 to dedicated desktop headphone amplifiers, including the April Music Stello HP-100 and Sicphones headphone amplifier. While I preferred the desktop units when it came to overall dynamic slam and bass extension, the AK100 had more than adequate gain and power to drive the Alpha Dog headphones successfully.
With most headphones, the most important aspect of their ergonomic performance is their fit. While the Alpha Dog certainly isn't uncomfortable, it's not the most comfortable pair of headphones I've used. The primary reason that they are bested fit-wise by the Sennheiser HD 600 and Stax Pro Lambdas is because of the Alpha Dog's excessive side pressure. I don't have a large head (6 7/8 hat size), yet I found that, after wearing the Alpha Dogs for a while, I was very aware of how much pressure the headband was putting on the sides of my head. Although the Alpha Dog's pads are sufficiently thick that the headphones don't actually touch my ears, the pads do push rather forcefully on the areas around my ears. I suspect that some prospective owners with large heads might find this pressure uncomfortable. Due to the springy nature of the Alpha Dog's headband, you can't merely s-t-r-e-t-c-h out the headband to accommodate larger heads. Eyeglass wearers will notice the side pressure especially on their temples.
At 440 grams, the Alpha Dog headphones are not exactly light. While not as heavy as the 533-gram Audeze rosewood LCD-2s, the Alpha Dog is not the sort of headphone you will ever forget you are wearing. While the Alpha Dog does deliver decent isolation and could be used for commuting and travel, I suspect its size, shape, and weight makes it more suitable for home and studio use.
Click over to page to for Sonic Impressions, High Points and Low Points, Competition and Comparison and Conclusion . . .
Sonic Impressions
To better understand why it is so difficult to make a closed-ear, sealed-cup design without "cup colorations," all you need to do is put on a pair of open-air headphones, such as the Audio Technica ATH AD-900 or Stax Lambda Pro headphones, and then put your hands over the outsides of the headphone enclosures. As you place your hands over the cups, you will hear the sound change as more sound is bounced off of your hands and back into the headphones. With closed-cup headphones, this "bounce-back" is a permanent condition that colors the sound. While headphone manufacturers have tried many methodologies for reducing this reflected sound to a minimum, such as adding a variety of sound-absorptive materials, the small size of the internal space and the necessity to keep a headphone as lightweight as possible have prevented manufacturers from using the kind of intricate matrixed interior absorptive technologies found in speakers like the original B&W Matrix 801. With the advent of 3D printing, though, MrSpeakers has created an earcup that can incorporate a far more complex and effective internal matrix design that damps reflected energy with much greater effectiveness than other cup designs made with conventional manufacturing methods.
How successful is the Alpha Dog's cup design at damping internal reflected sound? Compared with other conventionally-made, closed-cup earphones, such as the Beyer Dynamic DT 770 Pro, the Alpha Dog sounded more open, with less bonk in the lower midrange and upper bass and a less etched upper midrange and lower treble. The Alpha Dog headphones have the kind of refined upper-frequency presentation that I'm used to hearing from far more expensive headphones like the Audio-Technica ATH W-3000ANV. The Alpha Dog's imaging is much more like an open-backed headphone, with a large soundstage that delivers specific imaging cues. The Alpha Dog's soundstage was very similar to what I'm used to hearing from the Audeze LCD-2 headphones, especially on my own classical recordings. The Alpha Dog's lower midrange and upper bass were also similar in quantity and quality to the Audeze, with perhaps a bit more impact, but a bit less definition.
I did not attempt to readjust the Alpha Dog's Very-Bass bass adjustment screw. I suppose if I were a bass freak, I would have gone for bit more bass, not because I feel the Alpha Dog needed any additional bass but because bass freaks ALWAYS want more bass. I did find the bass was more dynamic and impactful when I used a dedicated desktop headphone amplifier, but even through the Astell & Kern AK100, there was adequate bass impact and extension.
The main reason for choosing a closed-ear design over an open ear one is for the isolation, both from outside sounds for the wearer and to prevent the sound from the earphones leaking out to disturb others. In both respects, the Alpha Dog does a fine job. Although not as isolating as an in-ear monitor like the Etymotic 4-P, the Alpha Dog does a more than adequate job of preventing your music from disturbing others and an okay job of isolating you from outside noise. In this respect, the Alpha Dog was very similar to the V-Moda M-80 over-the-ear headphones, in that some outside noise was still audible.
The "best" closed earphone that I had for comparison with the Alpha Dog was the Audio Technica ATH W-300ANS. The W-3000ANS's upper midrange and treble were more prominent and slightly more edgy than those of the Alpha Dog. The W-3000ANS sounds this way due to a "bright zone" of extra energy around 3K that gives music an extra bit of sparkle, but the final effect is less neutral and harmonically balanced than that of the Alpha Dog. Also, the W-3000 had an upper-bass bump when compared with the Alpha Dog, which could be considered "fun," but could easily become fatiguing during long-term listening sessions.
Oftentimes, high-resolution and revealing headphones can be harsh on lower-resolution sources, but the Alpha Dog avoids this sonic pitfall primarily because it has such smooth, controlled upper frequencies. Even Internet radio stations broadcasting at only 64 Kbps sounded tolerable through the Alpha Dog. With high-resolution sources, such as my own live concert DSD recordings, the Alpha Dog did a wonderful job of preserving all the subtle inner details.
High Points
The Alpha Dog has excellent build quality throughout.Low Points
Competition and Comparison
Although there are many closed-ear headphones on the market, none offer quite the same combination of neutral, uncolored sound, comfort, and build quality as the MrSpeakers Alpha Dog headphones. So far, I've not heard any closed-cup headphones that sound as open or offer the same amount of imaging specificity. The only headphones I've heard that rival the Alpha Dog's sonics are all substantially more expensive and open-air designs, such as the Audeze LCD-2 ($1,145) or Audio Technica ATH W-3000ANV ($1,495). Although writing that the MrSpeakers Alpha Dog "has no direct competition" leaves a reviewer open to criticism, I have yet to hear another closed-ear earphone at even double the price that achieves the same level of sonic finesse as the Alpha Dog. Sonic competition for this set of headphones starts at a substantially higher price tag, which is the new $1,799 Audeze LCD-XC closed-cup design.
Conclusion
If you require a headphone that delivers the isolation of a closed-cup design yet avoids the sonic pitfalls of a closed-ear design, you have few options, regardless of your budget. If your budget is $600 or less, as of right now, you really only have one option: the MrSpeakers Alpha Dog. The Alpha Dog headphones are more neutral and revealing than any closed-cup headphone design I've heard so far and rival some excellent open-ear designs in overall sound quality. Finally, if you plan to own only one pair of headphones, the Alpha Dog should be at the top of your audition list.
Check out the gallery below for pictures of the Alpha Dog and MrSpeakers other offering, the Mad Dog . . .
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