We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-02 · 7 min read · Independent comparison
If you want a do-everything recording front end that can properly drive high impedance studio headphones, choose Focusrite Scarlett Solo 4th; if you need a wired, isolating in-ear monitor for tracking, monitoring and gaming, choose H HIFIHEAR KZ AS16.
• Focusrite Scarlett Solo 4th — biggest strength: A true studio interface. One XLR mic preamp, one Hi-Z instrument input, 24-bit/192kHz conversion, a 120dB dynamic range, and a custom-designed headphone amp built to drive high impedance headphones louder and clearer. That last point matters more than most buyers realize.
• Focusrite Scarlett Solo 4th — biggest trade-off: It is not a listening device. It records. It has no headphone of its own, and nothing in the box makes sound until you plug something in.
• H HIFIHEAR KZ AS16 — biggest strength: Sixteen balanced armature drivers per side in a resin shell with a three-channel acoustic duct, 23.5 ohm impedance, 111dB sensitivity, and roughly 26dB of passive noise isolation from the ear-hook fit.
• H HIFIHEAR KZ AS16 — biggest trade-off: It is a 3.5mm wired IEM with no interface, no preamp, and no conversion. It also leans on a low impedance load, so it is built for phones, dongles and players — not for the headphone output of a big interface running hot.
• Who each pick is for: Solo 4th → the guitarist, vocalist or producer who needs to actually capture sound. KZ AS16 → the performer, gamer or listener who needs to hear sound accurately and quietly, right in their ears.
The Solo 4th is the songwriter's interface, and Focusrite says so plainly. You get one XLR mic preamp and one Hi-Z instrument input, which is exactly the pairing a solo artist needs: a vocal take on one channel, a guitar on the other. The Hi-Z input is designed to feel like plugging into an amp, so a DI guitar track through it behaves the way a guitarist expects rather than sounding thin and lifeless.
The headline spec is the 120dB dynamic range, and the converters are pulled from Focusrite's flagship interfaces. In practice that means headroom — quiet sources stay quiet, loud sources do not fall apart, and the noise floor has room to sit below the music. The improved Air mode adds presence and harmonic drive to vocals and guitars, pushing them toward the front of a mix the way a classic console would. Dynamic Gain Halos make level-setting visual and fast, which is genuinely useful when you are tracking alone with no engineer watching your meters.
Now the part that ties directly to this comparison: Focusrite built a custom headphone amp into the Solo specifically so it drives high impedance headphones louder and cleaner than the previous generation. If you already own a 250 ohm or 600 ohm pair of studio cans, that is the single most relevant line on the spec sheet. A lot of budget interfaces simply cannot push those loads to a usable level, and you end up with a headphone mix that is quiet, thin and hard to judge. The Solo 4th is aimed at that problem.
Who should buy it: the guitarist, vocalist or producer who wants to record and finish tracks, and who monitors on high impedance studio headphones. Who should skip it: anyone who just wants headphones to listen to music with. There is no headphone included. You are buying a recording tool, and the box ships with the Solo, a USB A-C cable and a software bundle including Pro Tools Intro+, Ableton Live Lite, Cubase LE and the Hitmaker Expansion collection. It runs on Mac, Windows and iPad, it is USB bus-powered, and it carries a three-year manufacturer warranty.
The KZ AS16 Pro is a completely different animal. This is a wired in-ear monitor built around sixteen balanced armature drivers — four high-frequency units, two mid-frequency units and two low-frequency units per side in the Pro layout. The three-channel acoustic duct structure splits the sound path so each driver group gets accurate airflow, which is how the tuning stays coherent across the range instead of turning into a mush of overlapping drivers. Frequency response runs from 20Hz to 40kHz, sensitivity is 111dB, and impedance is 23.5 ohm.
That 23.5 ohm figure is the important one for this article. These are low impedance, high sensitivity IEMs. They are designed to be driven easily by a phone, a laptop jack, a dongle DAC or a portable player. Plug them into something with a high output impedance and a lot of gain and you will hear hiss, and you will have almost no usable volume range before it gets loud. High impedance headphones want voltage; these want almost none.
What they do well is isolation and fit. H HIFIHEAR describes roughly 26dB of noise reduction from the combination of the ear-hook design and the custom-molded cavity shape, which keeps the shells locked in place and the cable routed behind the ear. If you are tracking a vocal in the same room as a live amp, or trying to hear footsteps in a game, that isolation is the entire point. The resin shells with the metal-inlay finish and the 2-pin detachable connector round out the package — the detachable cable means you can swap to a different cable later, and the OFC oxygen-free copper stock cable is built to resist pulling, bending and corrosion.
Who should buy it: performers, gamers, and anyone who wants accurate stereo monitoring without a bulky rig, plus a built-in mic and inline media controls for calls. Who should skip it: anyone who needs to record. There is no preamp, no conversion, no interface here. It is a listening and monitoring device, 3.5mm jack only, backed by a one-year warranty.
Side-by-Side: Which Should You Choose?
• Best for recording vocals or guitar → Focusrite Scarlett Solo 4th. One XLR preamp, one Hi-Z input, 24-bit/192kHz, Air mode.
• Best for low impedance, easy-to-drive listening → H HIFIHEAR KZ AS16. At 23.5 ohm and 111dB, it plays loud off almost anything with a 3.5mm jack.
• Best for noise isolation while tracking → H HIFIHEAR KZ AS16. Roughly 26dB of passive isolation from the ear-hook, deep-seated fit.
• Best for gaming and positional audio → H HIFIHEAR KZ AS16. Multi-driver stereo imaging and an inline mic in a wired, lag-free connection.
• Best for a full production workflow → Focusrite Scarlett Solo 4th. Pro Tools Intro+, Ableton Live Lite, Cubase LE and the Hitmaker Expansion tools are included.
• Best for portability → H HIFIHEAR KZ AS16. 30 grams, no power, no computer required.
• Best for a fixed desk setup → Focusrite Scarlett Solo 4th. USB bus-powered, Mac/Windows/iPad compatible, 3.78"D x 5.63"W x 1.83"H on the desk.
In my opinion, the Focusrite Scarlett Solo 4th is the product I would buy, and the reason is the one you came here for: high impedance studio headphones. The Solo is the only one of these two that is built to drive that load properly, and it does a second job that the KZ cannot touch — it records. If your goal is to make music and monitor on serious studio cans, the Solo is the answer. The KZ AS16 is an excellent, isolating wired IEM, and I would happily recommend it to a performer or gamer who already has a way to record. But if you can only pick one and headphones with a high impedance rating are in your future, buy the interface. Check the current price on Amazon before you decide.
do high impedance headphones sound better
Not automatically. High impedance changes how a headphone interacts with an amplifier, not the tuning itself. What it really demands is enough voltage to reach a usable level, which is why the Focusrite Scarlett Solo 4th's custom headphone amp — built to drive high impedance headphones louder and clearer — matters more than the impedance number alone.
is high impedance good for headphones
It can be, for studio use. Higher impedance loads are typically easier for a proper amplifier to control, and they tend to be less sensitive to hiss and noise. The catch is that they need a source with real output voltage, so a phone or a basic laptop jack may struggle where a dedicated interface will not.
are high impedance headphones better
Better for some jobs, not all. For critical monitoring on a desk with an interface that can drive them, they are a sensible choice. For portable listening off a phone, they are usually the wrong tool — that is where a low impedance, high sensitivity design like the KZ AS16 Pro at 23.5 ohm and 111dB makes far more sense.
why are high impedance headphones better
The argument is about amplifier behavior, not magic. A higher impedance load draws less current, and a well-designed headphone amp can drive it with more voltage headroom and less noise. That is precisely the design goal Focusrite states for the Scarlett Solo 4th's headphone output — louder and clearer with high impedance headphones.
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