The GK GST comes in a small box that’s very reminiscent of KZ or CCA earphones (you’ll find out why later). There’s an image of the earpieces on the front of the box and a list of specifications on the back. Inside the box, you get the GST earphones, a detachable 2-pin cable and 3 pairs of silicone eartips.
The GST has clear acrylic shells that let you see all of the earphone’s internals. It’s a pseudo-custom type shell worn with an over-ear cable. On the faceplates is the GK logo which is the only marking or colour. There’s a single vent on the inner side of the shell.
I couldn’t shake the feeling that I had seen this shell before. And sure enough, it turns out it is the KZ ZST X/CVJ CSA shell with a different logo printed on the side. Not only are the shells exactly the same, but the internals are the same too.
In terms of comfort, these shells are a great fit for my ears. This is hardly surprising considering I said the exact same thing about the KZ ZST X. You can lie down easily with these in your ears too thanks to their low profile.
Passive noise isolation is about average for this type of shell. The GST is suitable for bus rides, shopping malls and just about any other place you might find yourself in.
The included cable is par for the course for your average budget IEM. It’s a copper wire with a clear sheath on the outside. It has clear plastic connector housings, a KZ-like bendy Y-split and a right-angled plastic plug. When it comes to handling, this cable is pretty decent and has minimal microphonics.
So, the GK GST is essentially the KZ ZST X in a different colour shell. But for those of you reading who aren’t familiar with that IEM, I’ll break down the sound of the GST here. It has an energetic v-shaped signature which means the bass and treble are emphasized to create an engaging dynamic sound.
The GST has emphasized lows and deep rumbling sub-bass. It’s not a basshead IEM but there’s plenty of rumble there when a track calls for it. The mid-bass is punchy and meaty without showing any signs of distortion. There’s some mild bass bleeding into the midrange but overall, there’s good weight and control. Leading edges are slightly blunted but the level of definition is respectable for a budget earphone.
As is expected with a V-shaped sound signature the mids are slightly recessed. Although they could be described as slightly dry, the mids are still pretty smooth. Male vocals are a little lacking in texture but female vocals resonate clearly. Clarity and intelligibility are good and the detail retrieval is quite impressive too.
The GK GST’s treble is slightly forward and energetic but not what I would call bright. It is a touch uneven though and occasionally sounds a tad sharp but for the most part, it’s inoffensive. There’s not really any sibilance either unless it’s inherent in the recording.
Soundstage dimensions are pretty good and the stage depth is slightly better than average for something in this price range. Upper treble decay is a bit fast so it’s not the airiest or widest sound. Instrument separation is good for a budget IEM while the resolution and stereo imaging are average.
CVJ CSA ($18)
The CVJ CSA has the same shell as the GST. It has a warmer tonality and a thicker note size. It doesn’t have as much bass elevation as the GST nor as much bass texture but the extension is there. Lower mids are richer and more full-bodied on the CSA while female vocals are less vibrant than on the GST.
Although the CSA has less treble than the GST, it has less bass too. As a result, the CSA’s treble is actually quite lively and forward comparable to the GST.
KZ ZST X ($16)
The KZ ZST X has the exact same shell and internals as the GK GST. The sound signature between the 2 IEMs is nearly identical with the GST having 2-3dB more weight in the sub-bass. Whether this is an intentional tuning change or just unit variation I don’t know.
But to my ears, the GST sounds slightly better. It has a touch more warmth and body in the midrange compared to the ZST X. Furthermore, vocals sound a little more forward. The treble sounds a tad smoother too since it has that little dab of extra bass to help balance it out. Apart from that, these 2 IEMs are very difficult to tell apart in a blind test.
While the GK GST is undoubtedly good value and offers good performance for the price, it faces a challenge from the KZ ZST X which is essentially the same IEM at a cheaper price. The only reason I could see someone paying the extra cost for the GST is if they really want the clear shells. And I must admit, the GST’s clear housings do look pretty cool.