Reference tuning meets hybrid ambition
Reference-tuned in-ear monitors are premium in-ear monitors designed to deliver a neutral-leaning, studio-style frequency response that favors midrange clarity, treble extension, and accurate imaging over heavy, boosted bass. In other words, they try to sound like a reliable monitor rather than a nightclub PA. In this audiophile IEM comparison, the Punch Audio Martilo and XENNS Tea Pro SE show how differently a five-driver hybrid IEM can chase that goal—one through expansive soundstage and comfort, the other through metal construction and a warm tuning signature with refined treble. If you care more about critical listening than couch-rattling sub-bass, these two reference-tuned earphones sit right in your lane.
| Spec | Punch Audio Martilo | XENNS Tea Pro SE |
|---|---|---|
| Driver configuration | Five-driver hybrid: two 8mm dynamic drivers, two Knowles RDE balanced armatures, one planar driver | Eight drivers: two custom neodymium dynamic drivers and six Knowles balanced-armature drivers |
| Crossover | Not specified | Three-way crossover with 150 Hz low-frequency transition |
| Frequency response | 10 Hz–22 kHz | 20 Hz–22 kHz |
| Sensitivity | 100 dB @ 1 kHz (±1 dB) | 104 ± 1 dB |
| Impedance | 9 Ω @ 1 kHz (±1.5 Ω) | 13 Ω ± 1 Ω |
| Shell material | 3D-printed resin housing | Aluminum shells with steel nozzles |
| Cable & terminations | Cable with 3.5 mm and 4.4 mm plug adapters included | 1.2 m eight-core copper/silver Litz cable with modular 3.5 mm and 4.4 mm plugs |
Two engineering philosophies, one goal: precision
The Martilo and Tea Pro SE arrive at reference-style tuning from opposite design directions. Martilo leans on a five-driver hybrid IEM layout, pairing dual 8 mm dynamic drivers for lows with Knowles RDE balanced armatures for mids and a planar driver for treble, all pair-matched between channels for consistency. This is an unapologetically complex approach that tries to carve the spectrum into clearly defined jobs for each driver. XENNS instead doubles down on an all-balanced-armature-heavy stack: two custom neodymium dynamic drivers feed six Knowles BAs through a three-way crossover with a 150 Hz low-frequency handoff. That transition point matters; it signals a clear line between dynamic-generated weight and BA-delivered articulation. One is a hybrid playground; the other is a disciplined, engineered lattice in metal shells machined from aluminum with steel nozzles. Both scream “premium in-ear monitors,” but their priorities diverge.
Comfort, build, and soundstage: Martilo’s airy advantage
Martilo’s 3D-printed housing is shaped to hug the ear, with a smooth, lightweight shell that tends to disappear over long sessions. That ergonomic focus pays off for critical listening: you can stay locked in for hours without fidgeting. More importantly, the Martilo builds its identity on a broad soundstage and precise imaging, spreading instruments across a wide arc while keeping positional cues clear. This is where reference-tuned earphones gain their monitoring chops—by letting you place a hi-hat or backing vocal in space without strain. The trade-off is not invisible. The same tuning that boosts low-end force can leave midrange sounding recessed and hollow, and mid-bass can smear into slight messiness with acoustic or live recordings. Martilo feels like an IEM that wants to impress with width and punch first, and fine-grained mid detail second.
Tea Pro SE’s warm reference: mid-first discipline over slam
Tea Pro SE takes a stricter reference path, but wraps it in a warm tuning signature. Its bass is gently elevated around the sub-bass, easing into a linear lower midrange, then lifting through the 2–3 kHz region before sliding into a slightly relaxed lower treble and more prominent upper treble that adds sparkle and air. This is reference tuning with a hug rather than a slap. The reward is a midrange that stays organic yet articulate, and treble that sounds “exceptionally clean,” capturing transients and microdetail with less grain. Of course, something has to give. XENNS openly reduces bass emphasis compared with the original Tea Pro to keep tonal accuracy intact. In other words, it sacrifices some visceral impact for a more disciplined curve. According to the review, “the Tea Pro SE is a warm, north-of-neutral IEM with a reference-style sound signature.”
Who should buy which reference IEM?
Neither of these premium in-ear monitors is flawless, and that is where the choice becomes interesting. Martilo’s weaknesses live squarely in the reference world: mids can sound recessed and hollow, detail with acoustic instruments is limited, and mid-bass can drift into slight messiness. Tea Pro SE’s Achilles heel is emotional rather than technical; compared with its more energetic predecessor, it “lacks the sheer engagement” that fans of a punchier V-shape might expect. Both share a cautionary note: if you want a bass-forward thrill ride, you are shopping in the wrong aisle. These are reference-tuned earphones that prioritize midrange integrity and treble extension over club-level slam, with Tea Pro SE leaning warmer and smoother while Martilo stretches the stage wider and hits harder down low.
- Buy Punch Audio Martilo if you want a five-driver hybrid IEM with wide soundstage, strong low-end punch, and forgiving, slightly V-shaped listening that stays comfortable for long sessions.
- Skip Punch Audio Martilo if recessed mids and occasionally messy mid-bass bother you more than soundstage width or bass heft.
- Buy XENNS Tea Pro SE if you value a warm reference-style tuning with clean, airy treble, metal shells, and a more relaxed but detailed presentation near the top of its niche.
- Skip XENNS Tea Pro SE if you crave the “sheer engagement and energy” of the original Tea Pro’s more bass-emphatic V-shaped sound.
In the end, Martilo feels like a stage-focused monitor that sneaks some fun into its bass, while Tea Pro SE behaves like a studio-minded tool that keeps you listening with warmth instead of fatigue. Pick your reference: width and punch, or warmth and discipline.
