The BGVP NS9 arrives in your typical BGVP package, a compact box with 4 different types of tips for you to pick from, 3 pairs of “bass” tips, 3 pairs of “vocal” tips a pair of good quality foam tips, and the pre-applied wide bore tips.
Trying out all the tips, I find the pre-applied wide bore tips to sound the best as they seem to improve the bass just slightly.
Also in the box is a hardshell case, a very nice 4-core SPC cable, velcro strap, warranty info, and a small plastic container with 2 interchangeable “tuning filters” to try.
Cracking open the NS9 shell and looking inside reveals a seriously impressive assortment of drivers.
Two “FDK-60718” This is one of those double package ba units, it’s two Knowles drivers, one 60318 and one 30017, sandwiched onto each other. Said to cover the mids.
A Knowles RAF-32873, a balanced armature whose solder contacts are on the unit’s side, and on the back is this rubber gasket. 
A Sonion E50dt, this BA looks just like any other armature driver. a peek at the datasheet reveals this driver actually dual balanced armature, very interesting as these aren’t nearly as large as the double package FDK-60718s we see. Said to cover the highs & ultra highs.
One Coaxial dual dynamic driver. This is 2 dynamic drivers integrated into one package. The diaphragm material is advertised as being “liquid silicone” I believe this is a similar material as the hard silica gel balls you can find in those silica gel packets.
Let’s dive into the FR graph:
The 3 tuning filters
Combinations of tips+filters
At first glance, these look like a basshead’s delight, there is a full extension on both ends of the spectrum with the bass peaking at 20hz and treble information present around and after 16khz.
You may notice the lack of really any sort of upper mids emphasis, typically you see some sort of climb after 1k before dipping around 6k. Listening to the NS9 translates into a very laid-back mids/treble experience.
While on the graph all may look well, the actual listening experience leaves alot to be desired.
Let’s talk about the bass, it is a very very “slow” bass. It sounds mushy, soft, it is severely lacking in texture, i believe this is due the combination of having two dynamic drivers playing over each other and the bass being centered around 20hz.
On tracks with a heavy bassline, the NS9 totally lacks impact and texture.
Visually I can show you how slow the bass is by looking at the decay of the low frequencies:
The BGVP DMS for comparison
You can see how much quicker the decay of the BGVP DMS is when compared against the NS9’s decay.
It takes about 300 milliseconds for a 20hz impulse to fully decay on the NS9…
Focusing our attention on the mids, it’s another area where the NS9 fails to impress. Vocals are distant, instinctively while listening you will increase the volume to liven up the mids but doing so will only flood your ears with loud, dreaded mushy bass.
Due to the lack of upper-mid energy, overall clarity is lacking. Not for mids lovers.
The treble can be described as being good in quality, but lacking in quantity. A boost in the upper mids or treble would have greatly improved the perceived clarity of the music.
After 10k we see a drop, I say this is good as too much 12k will make the sound very unnatural (I’m looking at you V90S).
Then we see 3 peaks around 16khz giving the NS9 some much-needed treble resolution, this is one of the strong points of the NS9, the treble sounds extended with good air.
The soundstage is good, instruments are placed mostly away and behind you, treble instruments are placed a short distance away from your ears and the bass sounds like it’s coming from the same spot, the overall presentation isn’t convincingly realistic, there isn’t much sound coming from above or in front of you, everything is mostly localized either away, behind, or in your head.
The “tuning” filters that come with the NS9 are total gimmicks, they do little to nothing to alter the sound.
From the moment I laid eyes on the filters and inspected them it was clear to me that the only physical differences between the 3 were simply the different styles of metal mesh, of course, I can’t just claim such a thing without proving my theory, so I did an experiment. I removed the metal screens on one of each filter type and I measured them, expecting to see identical performance between the three.
The results of my experiment? Well, you can see for yourself, the filters are IDENTICAL to each other with the only difference being the color and the way the mesh screen looks.
So that’s it, we have extremely capable hardware. Somehow 7 balanced armatures equate to a lackluster upper mids/treble experience and the two dynamic drivers working in tandem are just flat out inferior to something like the single DD in the BGVP DMS. That, coupled with tuning filters that don’t actually tune anything. What we’re left with is an earphone that is at the very least, comfortable, and comes with very nice accessories.
The included cable is a thick, 4-core silver-plated copper (SPC) with half the cable being insulted with clear insulation, and the other half being insulated with grayish clear insulation. Looking at the structure up close it looks to be a Litz wire but isn’t advertised as such.
I bought my NS9 during the March Aliexpress sales as it was selling for $160.
Overall I find the NS9 hard to recommend.
Pros:
Treble extension and resolution
Comfortable, compact shell
Impressive hardware for the price
The included stock cable
Cons:
Bass lacks speed and texture
Lacking treble quantity
Tuning filters are a gimmick
Vocals are distant