Yinyoo BK2 featured

Yinyoo BK2 Earbuds Review – Steadfast

Tested at $51

Hey there fam! We’re back again, this time to review the Yinyoo BK2 earbuds. The BK2 has a 14.8 mm dynamic driver in each side, metal housings and a sweet detachable cable. So how does it sound? Let’s take a closer look.

  • Clear, balanced sound signature
  • Great build quality
  • Detachable MMCX cable
  • Bass may feel light for some

Special Offer for Prime Audio Reviews readers!

Get the BK2 for $31!

  1. Open the AliExpress link below. Click “BUY NOW”.
  2. In the order’s message field write “Primaudioreview”
  3. Click on “Other payment methods” and then “Confirm & Pay” button
  4. On the next screen click on “Cancel payment”
  5. Wait for the seller to manually adjust the price (this might take a while; you will receive an email telling you when the price has been adjusted)
  6. Go back to your cart and complete the purchase!

Buy on:

  • Impedance: 16ohm
  • Sensitivity: 96+3dB
  • Frequency Response: 5Hz-50000Hz
  • Cable Length: 1.2M

This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

Package and Accessories

We’ve seen a couple of different box types from Yinyoo so far; the simple black one that came with the NY-06 and Y1, plus the retail-styled blue and white box of the V2. The BK2 box is different again, this time it’s a lightly textured blue box with the Yinyoo logo on the top.

Inside is a black zipper carrying case (the same as the one that comes with the V2) seated in a black foam insert. The earbuds and other accessories are, naturally inside the carrying case. Let’s break down what you get:

  • Yinyoo BK2 earbuds
  • Carrying case
  • Detachable MMCX silver-plated copper (SPC) cable
  • 8 pairs of red doughnut foam covers
  • 8 pairs of black foam covers
  • Shirt clip

It’s a fairly basic bundle but hey, it’s an earbud, what did you expect? I like the inclusion of 2 foam types, as each one does alter the sound quite a bit and some will find the shirt clip handy too.

Yinyoo BK2 accessories

Build Quality and Design

I always find it more difficult to describe an earbud’s design because….well, they’re earbuds! The BK2’s housing are metal which gives them a premium feel but they’re also very lightweight. They’re available in 2 colours: black and silver.

First, we have the usual disc that houses the 14.8 mm dynamic driver with a perforated metal grill attached to the front. This is surrounded by a black, plastic ring which covers the join between the grill and the housing and provides some extra comfort.

Attached to the back of the disc is a small, metal cylinder which accommodates the female MMCX socket. On the rear face of the cylinder is some Yinyoo branding, along with a L or R marking indicating of course, Left or Right respectively.


The SPC cable is the same as the one we saw on the Yinyoo V2, which is a great cable for a budget item. It’s soft, pliable and is almost completely void of microphonics.

The MMCX connectors are aluminium and have Left or Right markers and a couple of etched rings to give your fingers something to grip onto. There is a small, metal chin slider just above the matching aluminium cylinder of the Y-splitter. This splitter is small and unobtrusive and has BK2 etched in white text on one side.

The cable terminates with a straight, 3.5 mm gold-plated plug with an aluminium housing. Overall the quality of this cable is excellent and well above average for something in this price range.

Comfort and Noise Isolation

As far as earbuds go I find the Yinyoo BK2 to be quite comfortable. It’s very similar in size and shape to the HE-150Pro; the main difference is the diameter of the stems which are larger on the BK2. I get a good fit with the earbuds but after a couple of hours I start to get hot spots and need to take a break or to reposition the buds.

Most earbuds offer very little passive noise isolation and the BK2 is no different. Having said that, I have used them in noisy environments without issue, although I had to increase the volume considerably. There is a fair amount of noise leak too, so that’s something to keep in mind if you want to listen to music in a library or quiet office environment.

Yinyoo BK2 with DAP


Gear used for testing includes the Shanling M0 and FiiO M6 DAPs or my Android phone and Earstudio ES100 for on the go sources. At home, I use MusicBee or JRiver Media Center on my PC with the FiiO K3 DAC.

Note that the 2 types of foam covers both have different attributes; the full foam covers add extra bass and warmth while the doughnut covers have more clarity and neutral sound. For the majority of my testing I used the doughnut covers.

The Yinyoo BK2 has a balanced sound signature with slightly forward vocals and boosted upper midrange. At 16 ohms the BK2 is very easy to drive and the average smartphone has more than enough power to push it (assuming it has a headphone jack).


A nicely controlled bass sets the stage for the BK2. It’s a fairly neutral and linear bass that is modest in quantity but never feels lacking. It has a medium paced attack and decay with enough punch to drive all genres of music.

Sub-bass extension is reasonable but it’s light with a fast rumble. It’s not the type of sub-bass that really excites but it is sufficient for most recordings. The bass texture is moderate and overall the BK2 has a tidy, polite low end.


The mids are the focus of the BK2’s presentation, sitting in front of the bass and treble. Vocals are forward in the mix but the BK2 deftly renders their density so that they don’t feel too intimate or invasive without becoming wispy and lacking solidity.

Thanks to the modest bass levels, the midrange is able to come to the forefront. The upper midrange is just a tad enhanced but overall things feel mostly linear throughout. A lot of earbuds can get muddy in the midrange but the BK2 sounds clear yet inviting at the same time.


There’s a nice balance of energy and smoothness in the BK2 treble. It sits just behind the midrange and has crisp, solid notes. Hi-hats and cymbals have good decay and realism.

There is no sibilance or harshness in the treble and no major peaks anywhere. A subtle boost in the lower treble adds some clarity to the midrange without stridency and the top end extends well enough to add airiness and lightness.


The BK2’s soundstage is average in size for an earbud with modest width and depth. The stage is surprisingly stable for an earbud and has well-defined boundaries. This aids imaging which is a strength of the BK2.

Instrument separation is solid and despite the midrange focus the stage doesn’t feel crowded or uncomfortably intimate.

Yinyoo BK2 with box and carrying case


HE 150Pro ($30 USD)

What immediately stands out is the difference in power requirements between these 2 entry-level earbuds; the HE 150 Pro (review here) is significantly harder to drive, although it does fine straight from my Android phone.

There is more bass presence on the HE 150Pro, in particular, sub-bass, which might make this bud more suitable for certain bass-driven genres, such as hip-hop or drum and bass.

The HE 150 Pro has a slightly darker and warmer tonality, which is a direct result of the enhanced bass carrying over into the midrange. In contrast, the BK2 sounds cleaner and a little brighter, although I still would not call it a bright sounding earbud.

HiFi Boy Dream ($89 USD)

HiFi Boy’s Dream earbud (review here) plays closer to neutral than the BK2. Bass is leaner and tighter as well, making the overall tonality drier. Transients are sharper and instrument separation is better on the Dream at the cost of some note thickness.

The end result is the Dream sounding more reference and analytical than the BK2. Another key difference is the Dream has a more expansive soundstage which again comes from the lean bass and midrange.

Both earbuds have a similarly smooth and airy treble. The Dream sounds more refined but its asking price is also quite a lot more than the BK2. In terms of build quality, both earbuds have metal housings and good cables but only the BK2 has the advantage of a detachable MMCX cable.

Penon BS1 Experience Version ($39 USD)

These earbuds sound really alike, with a similar tonality and presentation. The BS1 (review here) has a little more warmth but only a little and the difference is barely discernible unless you’re really looking for it.

The BK2 has a smidge more clarity and some extra detail in the treble but again the difference is minor. Despite having double the impedance, the BS1 has a higher sensitivity so the 2 earbuds output around the same SPL without changing the volume.

There’s hardly anything separating these in build quality too; the biggest difference is the BK2’s MMCX connectors/cable compared to the narrow stems of the BS1, which are more akin to the ones on the HE 150Pro.


A standout feature of the Yinyoo BK2 is its build quality; these are really nicely manufactured and feel quite premium. The addition of MMCX really adds to the value of any earbud or in-ear monitor in my opinion, so it’s great to see that here.

At its regular MSRP, the BK2 doesn’t stand out in particular when it comes to build or audio quality (although it is definitely competitive). At the discounted rate, however, it is much more compelling and well worth considering if you’re looking to buy your first earbuds or adding to an existing collection.

The Yinyoo BK2 is available on AliExpress here (don’t forget to follow the instructions at the top of this page to get your special discount!)

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Roden Becodo
Roden Becodo
4 years ago

There is no “order’s message field to write” in the page.

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