Introduction

QKZ, or Quality Knowledge Zenith, is one of those outfits based in Asia that you don't really know much about. The initials that make up the brand, and even the full form of the initials, would lead one to think there is some affiliation to KZ—another Asian audio brand that is most known for its budget-friendly set of in-ear monitors. QKZ is best seen as whatever the people behind the brand need it to be. Sometimes its an OEM for other companies, at other times it puts out compelling products at different price points that are well worthy of consideration. One such occasion resulted in a collaboration with IEM influencer/reviewer HBB (BGGAR), whose inputs have led to products such as the excellent Olina SE which remains my top recommendation at the $100 price point, if not more.


The original QKZ x HBB used a single dynamic driver and targeted the $20 market that has had quite a few offerings recently, and the newer QKZ x HBB Khan ups the ante with two dynamic drivers. There have been a few other such entries and, arguably, some credit can be given to the Truthear x Crinacle ZERO that started this dual DD driver configuration at a reasonable cost too. With the new Khan, QKZ and HBB both aim to put out a set of IEMs offering a balanced tonality while still providing ample amounts of clean bass too. Thanks to Linsoul for providing a review sample to TechPowerUp as we begin our coverage of the QKZ x HBB Khan with a look at the product specifications in the table below.

Packaging and Accessories

Packaging for the QKZ x HBB Khan employs a sleeve-over-box design that works quite well in providing a bunch of useful information to the end user. On the front is the brand logo in an iridescent finish as well as the product name itself to go with a render of the IEMs and a funny take on the Hi-Res Audio sticker everyone loves to use these days. I appreciate the factory frequency response on the back as well as the product specs and contact information for the registered company behind the QKZ brand. The acknowledgment to HBB for this collaboration is also neat to see. The inside cardboard box is black with a simple logo on the front and opening the lid reveals a souvenir metal coin that has both logos on it. The IEMs themselves are placed inside a protective cardboard sheet with machined cutouts and then we get the carry/storage case too—no paperwork of any kind to be seen here. This is a simple white hard plastic case with QKZ branding on the top and bottom and is small enough to easily fit in a pocket or be placed inside a bag. A latch keeps it closed on the front and I am personally a fan of this case in being different and functionally better—in my opinion—compared to what's typically provided in the price range these IEMs operate in.


Opening the case shows there is enough space to place the IEMs and cable inside, although a soft lining would have been nice. There are two separate plastic bags inside with the larger of the two containing the IEM cable itself and the other containing three sets of silicone ear tips in sizes S/M/L. Do try them all to see what works best for you among these, or grab aftermarket tips if you prefer. As far as stock tips go, these are on the better side of average in offering a medium bore size and decently stiff outer flange that doesn't buckle easily while still conforming to the ear canal well.

Closer Look

The cable that ships with the QKZ x HBB Khan looks and feels quite nice in person, so we are on a roll as far as the provided accessories go. This is a single-ended cable that has a 3.5 mm TRS plug on the source side with decent strain relief incorporated past the sizable housing it is fitted on to. The cable has four strands of oxygen-free copper conductor with a black sheath on top that is well braided to where I didn't experience any kinking in the way or much resistance to re-shaping either, let alone microphonics in use. The splitter is similarly executed as the rest of the hardware on the cable and then things will differ based on whether or not you have the mic or no mic version of the set. I have the latter here although the mic version comes with in-line microphone and controls on the right side cable as I understand. Then we get to my only gripe with the cable which is the highly stiff pre-formed ear hooks used here which necessitate a heat source to re-shape if the built-in curve doesn't conform to your ears well. The IEM connectors themselves use QDC-style 0.75 mm 2-pin recessed connectors with a sleeve over the actual pins. This adds some protection in use but does mean that the IEMs themselves won't easily take the more readily available 2-pin 0.78 mm cables. There is a red mark on the housing that corresponds to the right channel to help you identify them and the metal plugs are gold-plated for oxidation resistance.


The IEM shells themselves use DLP resin printing similar to a few others we've seen recently. The resin used is a dark black with some translucency allowing you to get a sneak peek at the drivers used inside. They do pick up finger oils and fingerprints to where I did find myself wiping them off every so often but not to the point of needing a microfiber cloth or remotely close to becoming a dealbreaker. The face plates themselves use a "dragon scale" motif with the QKZ and HBB logos in gold on the two sides. There's a polished metal cover around which helps glue the face plates to the shells and also contains the two vents at the bottom for airflow in and out the acoustic chamber. The top side has the product name and L/R markings if needed whereas the longer side shows the use of matching 0.75 mm cable connects that protrude outward. The shells are ergonomically designed to fit in the concha and are about average in size with a gentle slope heading down to the nozzle that is angled inward and on the longer and thicker side of average at ~6.2 mm at the widest spot. There is a defined end point and a retaining notch to help secure the ear tips which easily fit over the nozzle and remain there as seen above. A metal mesh filter at the end helps prevent contaminants from entering the acoustic chamber.


Installing the cable is simple enough with the pre-molded ear hooks that go over the ears and L/R indicators helping identify what goes where. Push the cable connectors into the IEM connectors as seen above until you see the external sleeve on the cable slide go over the IEM protrusions to form a more cohesive single unit.

Fit and Audio Performance

Seen above is the right side of the QKZ x HBB Khan installed in an anthropomorphic pinna that does well in showing my own experience with these. I have average-sized ears, and found the provided size M silicone tips to work fine, although you may want to look at aftermarket tips if you prefer, say, foam tips or do not get a good enough fit and seal with the stock tips. I'd classify the shells of the Khan to be about average in size although the exterior may lead you to believe they are larger than they actually are. We saw above how these are not thick and I had no issues fitting them in my ears. The nozzle is where those with smaller ear canals may have an issue however, so there is a case to be made for using thinner aftermarket tips such as the FiiO HS18 or cylindrical tips such as the DUNU S&S. The angled cable housing helps make use of the highly curved cable hooks in my case but here too you may want to use a heat gun or hairdryer to re-shape them if you find the cable to not fit over and behind your ears well. There isn't much physical fatigue here given the predominantly plastic composition leading to each side weighing ~7 g only.

I mentioned before how the QKZ x HBB Khan is a dual DD set and here we see the use of a 10 mm driver for the lower frequencies and a 7.8 mm driver for the mids and highs. Both use a polyurethane suspension and liquid crystalline polymer (LCP) composite diaphragm so at this point no doubt some would talk about the similarities in the drivers to those in the Truthear x Crinacle ZERO. The identical rated frequency response range (20 Hz to 39.5 kHz), impedance (10 Ω) and sensitivity (117 dB/Vrms) further adds to the similarities. Either way, the Khan is an easy-to-drive set where a basic dongle will be plenty enough, and I paired it with the Qudelix-5K and Questyle M15 for most of my listening experience.


Testing was done similar to all other IEMs, such as the recently reviewed MOONDROP Blessing 3. Seen above is the measured frequency response for both channels of the QKZ x HBB Khan which can be inspected further here if interested. Channel balance is quite good on this randomly picked retail unit and I'll also re-affirm there was no burn-in effect felt or measured here. The overall tonality of the Khan could be classified as Harman-like, which is why I have another graph seen above swapping out my personal preference target to the 2019 Harman in-ear target. What this means is oodles of bass, almost a guilty pleasure level for someone who is not that fussed about a lower level of bass in general, but generally focused under 200 Hz. This also shows where the two dynamic drivers effectively crossover here, with the larger 10 mm driver acting as a sub-woofer effectively in providing thunderous punch without causing a muddy bass or affecting the mids. The 10-11 dB bass shelf here makes for prominent kick drums and snare hitting in the beginning of a music set while still being fast enough to appreciate trailing ends of tones—think the twang of bass guitar strings. You might notice that sub-bass dip and think perhaps it's not a set conducive for electronic music and yet that's still a lot of energy there to not hold back EDM lovers either.

So while there is a significant amount of bass, it does not come at the expensive of recessed mids. In fact, I didn't experience any bass tuck here and had a smooth crossover to the other dynamic driver. Baritones and deeper male vocals might be a touch less forward facing relative to typical country music singers, I did have a few occasions where I wanted more body to the notes. Imaging is precise and soundstage is about average for IEMs in not being a defining feature by itself. What did make me happy was to see a relatively lower ear gain compared to the Harman target which I find shouty, if not sibilant. I still see the Khan as a brighter set that can be fatiguing if your library is treble-centric with a lot of acoustic jazz or classical music in the form of strings and piano pieces. I'd also point out the Khan isn't the most resolving set either but also in this market I am mostly looking for a well-tuned set that offers something different enough to be considered. In that sense I do think this does the job.