We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-24 · 7 min read · Independent comparison
If you want a sealed, high-impedance studio monitor you can wear in a noisy room and plug into proper audio gear, choose Superlux HD 661; if you need an easy-to-drive, featherweight wired IEM that works straight from a phone or handheld console, choose TANGZU Wan'er S.G II.
• Superlux HD 661 — biggest strength: a 68Ω sealed over-ear monitor design with a 40mm dynamic driver, 102dB sensitivity and a 10Hz–20kHz range, built for live monitoring, studio and broadcast work where isolation matters.
• Superlux HD 661 — biggest trade-off: it's a wired, full-size headphone with a fixed-cable-style package (two cables included), so there's no detachable cable upgrade path and no in-line mic for calls or mobile gaming.
• TANGZU Wan'er S.G II — biggest strength: a 20Ω, 113.5dB IEM that any phone, laptop or console can drive, with a detachable 0.78mm 2-pin silver-plated OFC cable and a Type-C option with mic.
• TANGZU Wan'er S.G II — biggest trade-off: it's an in-ear with passive isolation only, so it can't match the deep-earcup sealing a full-size closed monitor gives you, and its 20Hz–20kHz response trades the HD 661's 10Hz floor for portability.
• Who each pick is for: the HD 661 is for engineers, musicians and broadcast users who want a sealed reference headphone; the Wan'er S.G II is for gamers, commuters and everyday listeners who want a balanced, easy-to-power IEM.
The HD 661 is a sealed studio monitor headphone in a gray neoprene enclosure, and that single word — sealed — tells you most of what you need to know. A closed back means the cups keep outside noise out and your audio in, which is exactly why the design is pitched at live monitoring, studio use and broadcast. If you're tracking vocals in a room with a loud air conditioner, or cueing a mix on a noisy set, a sealed full-size headphone is the tool that keeps working when open-back designs would just leak the world in.
Spec-wise, it's a 40mm dynamic driver with a neodymium magnet, 68Ω impedance at 1kHz and 102dB SPL sensitivity. That 68Ω figure is the headline for this comparison: it's meaningfully higher than a typical portable IEM, so it behaves best when it's fed by something with real output — an audio interface, a mixer, a headphone amp, a dedicated player. On a bare phone it will still make sound, but the higher impedance means it wants more voltage than a 20Ω IEM does, and it's happiest when you give it that.
The frequency band runs 10Hz to 20,000Hz, and the tuning is described as high-resolution and balanced — the kind of voicing an engineer wants when they're checking whether a mix actually translates rather than being flattered by extra bass. In the box you get a 3.3 ft (1m) cable, a 9.8 ft (3m) cable, a gold-plated 3.5mm-to-6.3mm adapter, a cable clip and a carrying pouch. That long cable plus the quarter-inch adapter is a studio signal: this is meant to reach across a desk to a mixer or interface, not to dangle from your pocket.
Buy it if you want a sealed over-ear reference monitor for recording, monitoring or broadcast, and you already own gear that can drive 68Ω properly. Skip it if you want something for the gym, for phone calls, or for plugging straight into a controller with no amp in the chain.
The Wan'er S.G II Red Lion is the opposite philosophy in almost every respect. It's a wired in-ear monitor with a 10mm PET single dynamic driver tuned for gaming and music, and its whole design brief is "easy to drive, easy to live with." At 20Ω impedance and 113.5dB sensitivity, it's about as undemanding a load as you'll find — a smartphone, a laptop, a DAP or a handheld console will all push it to loud, full volume without strain. That's the practical payoff of low impedance and high sensitivity, and it's why this style of IEM has become the default for people who don't own a headphone amp and don't want to.
The sound signature is described as balanced and musical — deep, punchy bass with a tight rebound, warm natural mids for vocals, and smooth highs that avoid sibilance while still pulling out detail. That's a deliberately broad tuning aimed at pop, rock, hip-hop and gaming rather than a flat, analytical studio curve. The detachable 0.78mm 2-pin silver-plated OFC cable is a genuine plus: you can swap it if it wears out or breaks, and the design supports 3.5mm single-ended or USB-C plug variants — the Type-C version here includes a mic, which the HD 661 simply doesn't offer.
Comfort and fit get real attention too. The red translucent resin shell is lightweight at 18g, with an ear-hook anti-slip structure that keeps the buds seated during long gaming sessions, commutes and workouts. You get six pairs of ear tips, including wide-bore tips meant to tighten the seal and lift bass, plus a silicone carrying case, a cleaning cloth and cable management. Passive noise isolation is the name of the game here — it blocks some outside sound, but it's seal-dependent, not the deep earcup sealing of a closed over-ear.
Buy it if you want one lightweight IEM that handles gaming, music, calls and travel from whatever device is in your pocket. Skip it if you specifically need a full-size sealed monitor for studio reference work, or you want the higher-impedance behavior of proper monitoring gear.
• Best for high-impedance studio monitoring → Superlux HD 661. Its 68Ω load and sealed over-ear design are built for interfaces, mixers and amps.
• Best for plug-and-play from a phone or console → TANGZU Wan'er S.G II. At 20Ω and 113.5dB sensitivity, it needs no amp at all.
• Best for isolation in a loud room → Superlux HD 661. A sealed full-size enclosure blocks more than an IEM seal typically can.
• Best for gaming ergonomics and long sessions → TANGZU Wan'er S.G II. The 18g shell and ear-hook anti-slip design are made for hours of wear.
• Best for cable longevity and upgrades → TANGZU Wan'er S.G II. The detachable 0.78mm 2-pin silver-plated OFC cable can be replaced or swapped.
• Best for built-in mic and calls → TANGZU Wan'er S.G II. The Type-C variant includes a mic; the HD 661 has no mic.
• Best for deep bass extension on paper → Superlux HD 661. Its range reaches down to 10Hz versus the Wan'er's 20Hz floor.
• Best for travel and packing light → TANGZU Wan'er S.G II. It ships with a carry case and slips into a pocket; the HD 661 is a full-size headphone.
In my opinion, these two aren't really rivals — they're answers to different questions, and the "high impedance" keyword is exactly where they split. If your setup includes an interface, mixer, amp or dedicated player, I'd buy the Superlux HD 661. Its 68Ω, 102dB sealed monitor design is the more honest reference tool, and the two included cables plus the 6.3mm adapter show it was built for a desk, not a pocket.
If you don't own any of that gear — if your source is a phone, laptop or handheld — I'd buy the TANGZU Wan'er S.G II without hesitation. At 20Ω and 113.5dB it just works, and the detachable cable, six pairs of tips, mic option and 18g build make it the better everyday companion. So: studio chain, go Superlux. Everyday device, go Wan'er.
do high impedance headphones sound better
Not inherently. Higher impedance mainly changes how much voltage a headphone needs to reach a given volume. The HD 661's 68Ω design pairs well with amps and interfaces, while the Wan'er S.G II's 20Ω, 113.5dB spec is tuned to run cleanly from ordinary portable devices. "Better" depends on the source you actually own, not the number alone.
is high impedance good for headphones
It can be, especially in studio and broadcast use where gear is designed to deliver enough voltage. The trade-off is that a 68Ω headphone like the HD 661 wants a capable source, whereas a low-impedance, high-sensitivity IEM like the Wan'er S.G II runs loud from almost anything. High impedance is good when your chain supports it.
are high impedance headphones better
No — they're different, not superior. The HD 661's 68Ω load suits sealed studio monitoring where isolation and balanced tuning matter. The Wan'er S.G II's 20Ω load suits gaming, commuting and mobile listening. Match impedance and sensitivity to your source, and you'll get the best result from either.
why are high impedance headphones better
The usual argument is that higher impedance makes a headphone less sensitive to the output impedance of an amp, which can help keep frequency response consistent across different gear. That's a real engineering point, but it only pays off if your source can drive the load. The HD 661 needs proper gear; the Wan'er S.G II is the safer bet for casual listening.
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