In this video I do an in-depth review of the Kiwi Ears x Z Reviews Serene, a portable closed-back planar headphone that surprised me the moment I took it out of the box. The packaging is simple, but the headphone itself feels well thought-out: it’s light, compact, swivels flat, and the thick memory-foam protein-leather pads seal extremely well. I also go over the build details like the polymer cups, aluminum yokes, spring-steel headband, and a cable that honestly feels more premium than I expected at this price. Sound-wise, the Serene is very much a bass-focused tuning—classic “Zeos isn’t shy with bass” energy—but I wouldn’t call it V-shaped. To my ears it’s basically a relatively flat headphone with a significant mid-bass boost around that 150–200 Hz kick-drum region, with treble that stays neutral and controlled. Sub-bass is clean and linear, and the planar speed shows up in the separation and transient response. I also cover why the soundstage is unusually wide for a closed-back (it even reminded me of my Ananda Stealth in openness), plus imaging that’s precise enough that I’d genuinely consider it for competitive gaming. I also don’t skip the drawbacks: it’s hard to drive (an Apple dongle won’t cut it), there’s driver-flex crackle when you move the cups or walk around, and I really wish Kiwi Ears included a pouch and a modular/balanced plug—because this headphone clearly benefits from more power.