QKZ VK4 Impressions

I couldn't find other impressions of this IEM here, so I'm taking the liberty of starting a new thread.

The VK4 is a cheap ($10-$20) single-DD plastic Chinese IEM that's become an obsession of mine. For context, I also own stuff like the HD58X, Aeon Flow Closed RT, HE4XX, AKG K371 Andromeda 2019, Starfield, ThieAudio Legacy 4 and various cheap chifi IEMs. I also built and tuned my own headphones using the same 50mm drivers as the Aurorus Borealis. In the past I've owned LCD2C, DT1990 Pro, HD600 and others.

So, I've got a lot of options and yet the VK4 gets the most ear time. Why?

In short, I love the VK4's tuning and bass performance. Bass is north of neutral and extends looow, but despite some midbass warmth, it's more tight than tubby, reminding me of what I loved about the LCD2C bass. Orchestral stuff with tympanies sounds fantastic. Some people say it has too much bass, but with the right tips (Xelastec for me) and deep enough insertion, the bass sounds just right to me.

Upper mid balance reminds me of the HD58X - it's laid back compared to shoutier options like the HD600 or typical chifi, but not withdrawn like an Andromeda or LCD2C. This suits my personal preference, pulling back vocals just a bit to make room for instruments (great for metal like Tool and Dream Theater) but with enough energy not to sound hazy or dull (I'm looking at you Andromeda).

The mid treble has a distinct ear canal resonance peak that messes with timbre of cymbals and such, but isn't uncomfortable per-se, and upper treble lacks a bit of air which dulls pianos' upper harmonics a little, but on the whole the treble is not too bad.

Where the VK4 is known to suffer is in its resolving ability, which comes across as some lack of clarity. For casual listening this doesn't bother me, but for focused listening it takes something away from the experience, unless I turn up the volume to borderline unhealthy levels (which is fun but gets fatiguing pretty quickly).

My solution is EQ. I've gone through various iterations on this. One common factor is trimming the resonance peak (which you have to find for yourself, but is somewhere around 8KHz). You can gain clarity by reducing the bass, but then you lose what makes the VK4 great. My current formula that seems to work is to boost a little around 1.5KHz for clarity, and boost 12KHz for sparkle (really helps pianos). Maybe this doesn't actually improve "resolution", but it sounds clearer, more correct and more enjoyable, and keeps me from turning up the volume as much.

Drivability doesn't seem to be an issue, these work fine both from my phone and my dedicated amps.

P.S. One hears reports of unit variation, but the measurements I've seen from Crinacle (of 2 separate units), BGGAR and Antdroid all look very similar. I've also owned two pairs (first one failed on one side) and they sound basically the same. So there's that.

 

So I know I'm monologuing here, but I still love this thing! I'm currently rocking the below EQ and listening to some Mountain at relatively low volumes, and it's fantastic.

- Wide boosts at 700 and 1250 fill in the midrange a bit without making it sound thick. Helps make it sound more detailed too (though you lose a little soundstage).
- Boost at 13 KHz adds needed air, helps timbre and sense of openness
- Narrow cut at 20 Hz may seem odd, but with a good seal the VK4 has such extreme sub-bass presence that it can get fatiguing. Cutting a narrow band like this leaves the overall sound largely unchanged but takes away that uncomfortable pressure. It's still sounds good on Talvin Singh, even if it lacks some of the physicality (I know it's weird to talk about physicality in an IEM, but I can feel it on this one).