Syllable D900 Mini Review: Making Good Use of Immature Technology

I was approached by Syllable a couple weeks ago regarding the review of their new truly-wireless earphones. I wasn’t expecting much, given the extreme number of “truly wireless” earphones that are being pumped out every day. It’s a fad that has caught even Apple in its grip. I’ve got to say though, after a little bit of time for adjustment, the D900 Mini has gotten my respect.

Find the D900 Mini here on Amazon for $50.

Disclaimer: This review is based upon a sample unit provided to me by a manufacturer or distributor in exchange for my honest opinion and un-edited words. I do not profit in any way from the writing of the review. I would like to thank Johnson at Syllable for sending me this review unit.

Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoy-ability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.

My ideal sound signature would be an extended sub-bass with a leveled, but textured, bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.

Source: The D900 Mini was powered like so:

Nexus 6P -> Bluetooth -> earphones


Hidizs AP60 -> Bluetooth -> earphones

All music was served as MP3 @320Kbps or as FLAC.

Sound Signature

Initial Impressions:

My experience with the D900 Mini did not start as a positive one. I had to spend a solid five minutes pairing the D900 Mini, through no fault of the device itself. I just kept holding down the pairing button for too long, sending the D900 Mini into a completely unrelated mode. While I feel the process could be refined a bit, it’s nothing too strenuous. The included instruction manual is clear and concise.

After buffooning around for a bit with the pairing of the two D900 earphones, I had connected them to my phone and was ready for some listening. The default earbuds, however, were clearly not ready for me. No matter what I tried, I could not get a good seal. I begrudgingly began trying on the other earbuds included with the D900 and found that the smallest ones (coincidentally the last ones I tested) fit me the best, providing decent isolation and vastly improving the sound.

As for the sound itself, the D900 makes use of a standard V-shaped frequency-response; something that makes sense given the target audience of the D900 Mini. The treble is slightly in front of the recessed mids, while the bass is slightly more prominent than the treble. Clarity is decent, and frankly better than what I had anticipated.

Treble: Songs used: White Flag, Midnight City, Outlands

Treble is decent, providing some very minimal background retrieval of detail in White Flag. It’s not impressive in its own right, but is worth noting, once you take into account the low price-point of these earphones and their use of a fairly new and emerging technology.

Midnight City’s treble was smooth, with a medium speed. The result is a very laid-back sound. I did find that the D900 Mini seems to almost completely ignore the finer textures of the treble, leaving behind just the macro-sounds.

Within the layered sound of the violins of Outlands, I was able to quantify the coloration of the treble; there is a notable upper-treble roll-off. This does impact the open and grand feeling that properly-mixed classical tracks can impart. However, the actual layering of the treble was decent. The bottom-most violin layer did not stay solid for the entirety of the song, which I expected given that the D900 Mini runs off of a Bluetooth connection.

Mids: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Good Life

The mids of the D900 Mini are quite good for the price, containing a decent amount of texture and detail. While it’s behind its wired peers in this respect, I find that the D900 Mini does a good job for casual listening. The guitars of Flagpole Sitta were separated from the mix for most of the song, but ultimately failed to deliver that electric “crunch” I generally look for.

Jacked Up’s pianos had a hard edge, indicative of a good attack and decay for the mid range. The upper-mids were slightly clouded, with smudging occurring even in less-busy songs.

Bass: Songs used: Lights, Gold Dust, In For The Kill (Skream Remix), Leave Me

Bass is slightly boomy, and is rather lacking in definition. This did not become a problem in Lights, as the kick-drum still had a satisfying thud and the chorus contained a good amount of rumble.

Bass extension is overall pretty mediocre. While not too shallow, it certainly doesn’t reach the levels I would have liked. This was shown quite easily when playing In For The Kill through the D900 Mini. Its dynamic drivers struggled to push their operating frequency down. I hesitate to call this is a significant problem, as it didn’t effect the casual enjoyability of the song that much.

Clarity: Songs used: Throne, Map of The Problimatique, I’m Not Alright

Long story short, the D900 Mini is not very clear. Budget-grade dynamic drivers combined with Bluetooth double-pairing make for a pretty underwhelming experience in this section. While I didn’t get any distortion, I did notice a good amount of mid-range and treble smudging during Throne, Map of The Problimatique, and I’m Not Alright.

Packaging / Unboxing

Syllable packaged the D900 Mini in a plain cardboard box. The entire unboxing experience is minimalistic, but is something I can get behind in order to maximize the price-to-performance ratio of the D900 Mini.


Construction Quality

The D900 Mini is built from a smooth plastic. It is light, and fairly sturdy. The back of each earphone contains one button that functions as inline controls. They are fairly tactile, but don’t feel super durable. On the side of the earphones you can find the status LED and the bass port.

Connectivity / Battery Life

The D900 Mini utilizes Bluetooth to connect to mobile devices, and uses a slaving system to pair the two earbuds. This works well, better than even the mighty Bragai Dash, a device that has myriads of range and pairing issues, despite literally costing almost 6 times as much.

I was able to get 19 feet of range inside, and roughly 26 feet of range outside before the Bluetooth connection cut out. Upon reconnecting, the earbuds slowly faded back in to my music. This is to make sure that a sudden disconnect and reconnect does not surprise the listener or hurt their ears. It’s a nice touch, and something I appreciate, as the D900 mini does occasionally suffer a disconnect of the right earbud. I find that restarting both earbuds does usually help alleviate this issue.

The earbuds are charged inside of a portable cradle which holds enough capacity to charge them five times over. The cradle secures earbuds in place magnetically, and then charges them over a two-pin contact system. It is possible to place them in the cradle without the pins aligning correctly, so it is generally a good idea to check that they are seated well before actually leaving them to charge. You can tell by closing the lid and then checking to see if the earbuds’ inbuilt LED is glowing red.

The D900 Mini earphones themselves have an operational time of up to two hours, a figure I was able to get very close to. My maximum listening time so far has been 1 hour and 52 minutes, with an average play time of 1 hour and 44 minutes.


On the backside of each of the D900’s earbuds you can find one large button which can answer calls, call back the last number, and pause/play music.


The D900 Mini is surprisingly comfortable. The light build combined with the custom eartips makes using the D900 mini for its two hour charge time a breeze, without a hint of discomfort throughout my regular listening sessions.


Inside the box you will find:

  • Charging cradle
  • Flat Micro-USB charging cable
  • 2 sets of extra eartips
  • Soft carrying pouch

Suggestions for Syllable

I would definitely decrease bass response, or at least increase treble response. A couple of minutes with my Nexus 6P’s EQ showed that these earphones have the potential to be better than ok. My adjustments were made on Black Player’s 5-band EQ.

  • -1dB to the 60Hz band
  • -2dB to the 230Hz band
  • +3dB to the 14000Hz band

These adjustments opened the up the sound and allowed me to listen at much higher levels of volume comfortably.

I also urge you to address the disconnecting issues. While I can forgive it happening once or twice during a two hour sessions, any more than that really throws a wrench in the listening experience.

  • First session: 0 disconnects
  • Second session: 3 disconnects
  • Third session 5 disconnects
  • Fourth session 2 disconnects


The D900 Mini has some short-comings. It lacks sub-bass rumble and has upper-treble roll-off. It occasionally disconnects the right earbuds from the left. However, it also does a lot of things right. Charging is quick and easy, and the carrying cradle is designed well. It’s comfortable to wear, and easy to fit. Not to mention, it’s based on a very new technology that has existed for fewer than 18 months. I wouldn’t mind buying this for $50, but at the same time I would probably like to wait and see how things progress from here in the truly-wireless market. If you want to be an early adopter, go for it. Just make an educated purchase.

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