Alpha & Delta D6: Challenging “The King”


Today we’re checking out Alpha & Delta’s flagship earphone, the D6.

Alpha & Delta (A&D) is the in-house brand of the popular retailer out of Singapore, Lend Me Ur Ears. The brand was launched with a simple but rugged sports earphone, the D2, which was well-received within the portable audio community. That was followed up by the dual dynamic AD01 which warmed the hearts and ears of many. Since then, the brand has expanded further with a number of new products. The D3 features a 6mm micro-driver which puts out one heck of a low end. The JAAP is a fully wireless Bluetooth earphone with competitive specifications like an achievable 6 hours of battery life. Last but not least is the audiophile targeted D6 that we’re checking out today.

The D6 features single 10mm dynamic drivers per side with an 8 core, silver-plated copper cable connecting them to your playback device. A&D has also licensed HDSS and dual-chamber tech for use in the D6, something I am familiar with from my time with Blue Ever Blue’s products. Now, I can’t definitively say that the HDSS effect is in play since for that we would need identical models to compare, one with and one without HDSS. That said, I can confirm that the D6 shares qualities with other HDSS and dual-chamber equipped earphones I’ve got, and that’s a good thing. In addition to the developments made to craft a good sounding product, A&D is also obviously confident in the quality of their materials and workmanship. The D6 is backed by a three year warranty, something that’s not particularly common in the industry.

So, does the D6 stand tall as Alpha & Delta’s current flagship, or is it a has-been with some neat tech but mediocre sound? Let’s find out.



A big thanks Dennis with Alpha & Delta for reaching out to see if I would be interested in reviewing the D6, and for arranging a sample unit. All thoughts within this review are my own and do not represent A&D or any other entity. There was no financial incentive provided.

At the time of this review the D6 could be picked up for 133 SGD or 94.68 USD here;

Personal Preferences:

I listen primarily to various EDM sub-genres (liquid drum and bass, breakbeat, drumstep, etc.), hip hop, and classic rock. While I enjoy a variety of signatures in my headphones I generally lean towards slightly warm with elevated treble and sub-bass, an even and natural mid-range response, with reduced mid-bass. The HiFiMan RE800, Brainwavz B400, and thinksound On2 offer unique examples of signatures I enjoy.


For at home use the D6 was powered by a TEAC HA-501 desktop amp or straight out of my Asus FX53V laptop. For portable use it was paired with an LG G5, HiFiMan MegaMini, or Shanling M1. The Walnut F1 also made it’s way into the rotation at times. The D6 was exceptionally easy to drive.


  • Driver unit: 10mm dynamic driver
  • Impedance: 16 ohm
  • Rated power: 1mW
  • Frequency Response: 10 Hz – 70 Khz
  • Speaker Sensitivity: 105+/- 3db
  • Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
  • Plug: 3.5 mm

Packaging and Accessories:

The D6 doesn’t come in any sort of packaging that’s going to blow you away with layers of intricacy or upscale styling. Nope, it’s pretty basic. The base grey cardboard box lists on the back the contents and accessories along with the specifications. The entire front is a clear plastic viewing window showing off the earphones nestled within a foam insert. Lifting out the viewing window reveals a gorgeous leather carrying case containing the rest of the accessories, of which there are many. In all you get;

  • D6 earphones
  • Leather carrying case
  • Leather cable tie
  • Silicone ear guides
  • 3 sets of single flange silicone ear tips in s/m/l (9 pairs total)
  • 1 pair of foam ear tips
  • Shirt clip

It seems like A&D made a trade off; inexpensive packaging in exchange for plenty of quality accessories. That’s a trade off I’m perfectly happy with. The case and cable strap feel great, the ear guides are handy for over-ear wear, and the tips are all different so the variety make sense. Good stuff here.

Build, Comfort, and Isolation:

Alpha & Delta back this earphone with a solid warranty, and I can see why; it’s very well-constructed. The metal housings are a dark gunmetal chrome with design inspiration taken from ammunition in the placement of the various ridges and channels. While fairly large, they are quite light and all edges are rounded off so there are no sharp edges. This is great for comfort because the nozzle is a touch on the short side meaning the inner edge of the housing is likely to lean against your ear. Other earphones built like a similar girth that do not have rounded edges cause hot spots and mild outer ear pain. Not an issue I’ve come across with the D6.

The cable is the real show stopper though. The D6 uses a wonderful braided eight core, silver plated copper cable. The sheath has a slightly gummy and grippy feel to it that holds on to skin quite effectively, yet slides over clothing with little resistance. This makes the included ear guides a little redundant in my opinion, as the cable sits very securely around you ear without them should you choose to wear them cable up.

Strain relief is usually an area where I have some bones to pick. For the most part, the D6 is fine here. Leading into each ear pieces is a very KZ-esque rubber relief but with just enough give to make it effective. On the left side is a tiny little bump to indicate the left channel, something A&D reminds you of with a small strip of paper found in the packaging. This is a little too ambiguous for my liking, and would prefer if they just printed a small L and R somewhere on the ear pieces. The 90 degree angled jack goes with a tightly coiled spring instead of a more traditional rubber relief, something usually only found on much more expensive products. The y-split’s relief isn’t fantastic being that it is so stiff there is next to no flex. Still the cable feels durable enough to make this less of a concern than it otherwise would be.

In terms of isolation, the D6 is flat out average and won’t be winning any awards. Using them at work I could hear keyboards clattering away, murmuring, etc. Using them outside, cars are well present, as are other noises. These would be fine for walking around in a grocery store or going to the shop, but for transit? I’d be looking elsewhere.

HDSS (High Definition Sound Standard):

This tech boasts some interesting claims, such as a clinically tested and approved 14.32 reduction in psychological stress, detailed 3D sound reproduction, and virtually no distortion. While I’m not going to state my thoughts on some of those claims, I will state that I have tried quite a few earphones with HDSS and their dual-chamber tech, all from Blue Ever Blue. Ear fatigue seems to be vastly reduced as there is next to no back pressure once you’ve got a good seal. My time with the D6 mirrors my past experiences with BeB’s HDSS equipped products. Those that are big on protecting their ears and hearing might want to keep the D6 in mind.


The D6 is a very coherent sounding earphone with a well-balanced signature, blending bass, treble, and mids wonderfully. Treble is uncharacteristically smooth and tight for something in this price range, especially if you’ve become accustomed to the rarely filtered sound of BAs used in budget hybrids. It is calmly accentuated with mild peaks in place to give it’s upper ranges a very specious and ethereal presentation. Attack and decay are quick, but not so quick that lingering notes trail off too quickly. Detail and clarity are above average for a single dynamic, and serve listeners well by giving them lots of information about what’s going on in any given track.

The mid-range is much the same though it has a touch more warmth to it. Timbre is spot on with instruments and vocals sounding as they should. What gets me most is how smooth vocals sound while still retaining a level of coherence you’d usually associate with a leaner sounding earphone. Throwing on “Beat It” by Michael Jackson, the awesome guitar solo is crisp and texture, though not quite as forward as it is through other similarly tuned products like the Blue Ever Blue 1200EX. It also lacks some weight and presence. The D6 fairs much better with “Billy Jean” and other tracks rich with synth work.

Bass on the D6 is elevated slightly over neutral with great texturing and decent extension. The balance between mid- and sub-bass is quite even, with neither taking on a larger presence. The D6’s bass doesn’t have a ton of slam or authority to it, going more for a detailed presentation than visceral. Not really my preference, but it works in conjunction with the way the mid-range and treble are presented. They’re certainly not a bassy earphone, but they’re got more umph down low than your typical BA only product, and some other single dynamic models like the Whizzer A15 Pro Haydn.

Another area the D6 stands out to me is sound stage, a quality I find common among other HDSS equipped earphones like the aforementioned 1200EX and 2000EX. It might be the dual-chamber design and/or plain old good tuning, but whatever it is gives the D6 a wonderfully open presentation that has no issues throwing sounds a good distance from my head. Listening to Infected Mushroom’s “Groovy Attack” is a trip as effects flash around the stage. This also serves to highlight some impressive layering. Congestion is avoided as a result of quality separation as evidence when listening to King Crimson’s “Starless and Bible Black”. After an agonizing 4 minute build, the track shifts gears with a mild blowing jazz attack that can get messy with poorly separated earphones. Not the D6.

Select Comparisons:

(Volumes matched as best as possible with the Dayton Audio iMM-6)

Blue Ever Blue 1200EX (105.00 USD): Like the D6, the 1200EX features HDSS with dual-chambers. The 1200EX’s housings are a mix of metal and plastic with an extended nozzle section designed to hold the various stabilizing ear hooks that come with it. Because of this design and the angled nozzles, the 1200EX meant for cable down wear only, unlike the D6’s more universal barrel shape which works cable up or down. I quite like the 1200EX’s cable which has a very dense, durable shealth, but it’s slightly stiff (especailly so in the cold) and isn’t quite as well relieved. Overall build quality goes to the D6 with it’s more impressive materials along with better fit and finish. The 1200EX’s shell does fit my ear a little better though.

In terms of sound the two have slightly different takes on the same signature. The D6 is a touch thinner and more skewed towards upper mids and lower treble giving it a bit more sparkle and air. The D6’s mid-bass is maybe a dB or two more emphasized compared to the 1200EX. Neither has particularly prominent sub-bass, but I’d give the edge to the 1200EX. The 1200EX’s mid-range is slightly more articulate but equally present. It has a slightly drier texture that I feel gives it the edge with male vocals. In terms of sound stage, layering, and separation I couldn’t really hear much of a difference, though imaging felt more accurate through the D6. Texture and detail between the two was again more or less equal.

TFZ Exclusive King (99.00 USD): The King’s housings are mostly plastic with a metal faceplate. Fit and finish is quite good, but falls short of the D6. There is a notable gap between the faceplate and rest of the ear piece which hides some vents. The D6’s build is tighter and more consistent. The King is is a very large earphone that takes up pretty much the entirety of you outer ear and is designed for over ear wear only. If you have small ears or like to wear your earphones cable down, the D6 will better meet your needs. In terms of cables, the King’s cable is a much thinner braided option. It is replaceable though, terminated in a 2-pin connector. The D6’s cable is nicer, but fixed.

Just as with the 1200EX, the King and D6 have different takes on the same signature. The King’s upper treble is slightly more emphasized but not as smooth and articulate. The King has a more forward, detailed, and textured mid-range than the D6. The King’s low end definitely has more punch to it. It hits harder, feels tighter, and is more layered and textured. It also extends deeper with more sub-bass emphasis, and a dialed down mid-bass region. The King is more in-your-face than the D6.


Final Thoughts:

Alpha & Delta’s D6 is a strong entry in the ~100 USD market with a fairly balanced signature that is lightly treble-leaning; one that is very detailed, smooth, yet decidedly non-fatiguing. It could use a touch more sub-bass extension and emphasis for my tastes, but as-is is still quite pleasing. That it goes toe-to-toe and blow-for-blow with the Blue Ever Blue 1200EX and TFZ Exclusive King, two of my favorite earphones in this category, says a lot about how capable the D6 is.

While the shiny gunmetal chrome look isn’t for everyone, you can’t deny that it was executed exceptionally well. The D6’s material quality and fit and finish is impressive as well, with good comfort too despite being a little on the bulky side. Many would think the D6 would benefit from a removable cable, however, the fixed cable that is on there is absolutely gorgeous and is well-relieved. It feels like it will last.

If you’re looking for a strong performer around 100 USD, be sure to look into the D6. Thanks for reading!

– B9Scrambler

***** ***** ***** ***** *****

Some Test Tunes:

Aesop Rock – Skelethon (Album)

Daft Punk – Random Access Memories (Album)

Elton John – Yellow Golden Brick Road (Album)

King Crimson – Lark’s Tongues in Aspic (Album)

King Crimson – Starless and Bible Black (Track)

Supertramp – Crime of the Century (Album)

Infected Mushroom – Converting Vegetarians (Album)

Infected Mushroom – Legend of the Black Shawarma (Album)

Gorillaz – Plastic Beach (Album)

Massive Attack – Mezzanine (Album)

Fleetwood Mac – Rumors (Album)

Run the Jewels – Run the Jewels (Album)

The Prodigy – The Day is My Enemy (Album)

Tobacco – F****d Up Friends (Album)

Felt – Felt 2 (A Tribute to Lisa Bone) (Album)

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