BASN Metalen 4 Drivers In-Ear Monitors Headphones Review: A Musician’s Deep Dive into Audio Fidelity

As a musician and audio engineer, my world is a constant battle between signal and noise. Whether it’s the chaotic bleed of a live stage where the drummer’s cymbals are threatening to decapitate the vocalist’s mix, or the subtle hum of a studio air conditioner during a delicate acoustic take, unwanted sound is the enemy of a great performance. For years, the solution was bulky, uncomfortable over-ear headphones or, worse, floor wedge monitors that created a feedback-laden sonic warzone. The search for a monitoring solution that offers both pristine audio clarity and significant isolation can feel like an expensive, never-ending journey. Failing to find the right tool doesn’t just result in a bad mix; it leads to ear fatigue, pitch problems, and performances that lack confidence and precision. This is the exact problem that professional-grade in-ear monitors (IEMs) were designed to solve, promising a personal, isolated soundscape where every note can find its place.

What to Consider Before Buying In-Ear Monitors

An In-Ear Monitor system is more than just a pair of high-end earbuds; it’s a key solution for performers, engineers, and audiophiles seeking unparalleled audio detail and isolation. By creating a direct seal in the ear canal, IEMs block out a significant amount of ambient noise, allowing you to hear the monitor mix at a lower, safer volume. This protects your hearing while enabling you to discern every nuance of your performance or recording. The main benefits are threefold: superior sound quality with detailed frequency separation, hearing protection on loud stages, and a consistent sound experience regardless of venue acoustics. The BASN Metalen 4 Drivers In-Ear Monitors Headphones enter this competitive space with a compelling feature set aimed squarely at the professional user on a real-world budget.

The ideal customer for this type of product is a gigging musician—a singer, guitarist, drummer, or bassist—who needs to hear themselves clearly amidst the din of a live band. It’s also perfect for studio engineers and producers who require a detailed and reliable reference for mixing and tracking. However, it might not be the best fit for those whose primary need is active noise cancellation for travel or commuting. IEMs provide passive noise isolation, which is highly effective but fundamentally different from the electronic noise cancelling found in popular consumer headphones. If you’re simply looking to silence the drone of an airplane engine, a dedicated ANC headphone might be a more suitable choice.

Before investing, consider these crucial points in detail:

• Fit & Comfort: IEMs are worn for hours at a time during rehearsals, performances, or studio sessions. The ergonomic design of the shell and, crucially, the type and size of the eartip are paramount. An improper fit not only causes physical discomfort but also completely compromises sound quality and noise isolation. Look for a product with a wide variety of included silicone and memory foam tips to ensure you can achieve a perfect seal.
• Driver Configuration & Performance: The “drivers” are the tiny speakers inside the IEM that produce sound. The BASN Metalen boasts a quad hybrid setup: two dynamic drivers (DD) for rich, powerful bass and two balanced armature (BA) drivers for crisp, detailed mids and highs. This hybrid approach aims to deliver the best of both worlds, providing the punch needed for rhythm sections and the clarity required for vocals and lead instruments.
• Materials & Durability: A musician’s gear takes a beating. IEMs built from plastic can be prone to cracking. The BASN Metalen 4 Drivers In-Ear Monitors Headphones are constructed from CNC-milled aluminum alloy, offering a significant step up in durability and a more premium feel. Detachable cables, especially with a robust connector like MMCX, are a must-have feature, as the cable is often the first point of failure.
• Ease of Use & Maintenance: A good IEM package should be a complete kit. This includes a protective carrying case, a cleaning tool to keep the sound bores clear of debris, and often, multiple cable options. The inclusion of both a pure audio cable and one with an in-line microphone adds versatility for use beyond the stage, which is a significant value-add.

Choosing the right IEM is a critical decision for any serious musician. While the BASN Metalen 4 Drivers In-Ear Monitors Headphones present a formidable option, it’s always wise to see how it stacks up against the competition. For a broader look at all the top models, we highly recommend checking out our complete, in-depth guide:

First Impressions: Unboxing a Premium Toolkit for Your Ears

From the moment we opened the box, it was clear that BASN aimed for a premium, professional experience. There’s a satisfying density to the package that immediately signals quality. Inside, nestled in precision-cut foam, were the stunning Sapphire Blue earpieces themselves. The CNC-milled aluminum shells felt cool and substantial in hand, a far cry from the plastic bodies of many competitors in this price range. The finish is impeccable, with a finely textured, almost matte surface that resists fingerprints and looks absolutely superb. As one user aptly put it, the build quality feels like “pure premium.”

The accessory package is exceptionally generous and thoughtfully curated. You don’t just get one cable; you get two. The first is a beautiful, silver-plated braided cable designed for pure audio monitoring, terminating in a gold-plated 3.5mm jack. The second is a more conventional cable featuring an in-line microphone and controls, perfect for taking calls or casual listening. The array of eartips is extensive, with multiple sizes in both silicone and memory foam, ensuring that nearly any user can find a secure and comfortable fit. The inclusion of a sturdy carrying case, a 1/4-inch adapter, a cable clip, and a cleaning tool rounds out a package that feels complete and ready for the road right out of the box. You can explore the full accessory list and design details on their product page.

Performance Under Pressure: A Deep Dive into the BASN Metalen’s Sound and Build

An IEM can look beautiful and come with a treasure trove of accessories, but none of that matters if it doesn’t perform when the lights go down. We put the BASN Metalen 4 Drivers In-Ear Monitors Headphones through its paces in a variety of scenarios—from live band rehearsals to critical studio mixing sessions and casual listening—to see if its quad-driver heart could deliver on its promises.

The Quad-Driver Hybrid Sound Signature

The core of the BASN Metalen’s appeal is its complex quad-driver setup: two dynamic drivers paired with two balanced armature drivers per side. This hybrid configuration is an ambitious engineering choice, designed to leverage the strengths of each driver type. Our testing revealed a sound signature that is undeniably powerful, engaging, and well-suited for its target audience of musicians. The two dynamic drivers are tasked with the low frequencies, and they perform their duty with authority. The bass response is deep, impactful, and has a satisfying rumble that drummers and bassists will immediately appreciate. On tracks like Rage Against the Machine’s “Bombtrack,” the kick drum hits with a physical thud, and the bassline is full-bodied and present without turning into a muddy mess. We found the lows to be well-controlled, offering punch rather than just boomy, undefined noise.

Handling the midrange and treble are the two balanced armature drivers. This is where vocals, guitars, and cymbals live, and clarity here is non-negotiable for a monitor. The BASN Metalen delivered admirably. Vocals cut through dense mixes with excellent definition, and the snap of a snare drum or the shimmer of a hi-hat was rendered with crisp detail. The BAs provide a level of speed and precision that dynamic drivers alone often struggle with, ensuring that intricate musical passages don’t become congested. The overall soundstage feels wide for an in-ear, providing good stereo imaging that allows you to place instruments within the mix effectively. While it’s not a ruler-flat, analytical sound—there’s a definite warmth and low-end emphasis—it is a musical and inspiring one, which is arguably more important for performance. This is a feature set that truly punches above its weight.

Built for the Road: Durability and Ergonomics

A musician’s gear lives a hard life, tossed into gig bags and subjected to the rigors of setup and teardown night after night. The full-metal construction of the BASN Metalen 4 Drivers In-Ear Monitors Headphones inspires immediate confidence. The CNC-milled aluminum alloy shells feel virtually indestructible compared to the hollow plastic common in this category. There’s a pleasing weight to them that feels premium, yet they are not so heavy as to cause discomfort during long sessions. The ergonomic shape is well-conceived, designed to nestle securely within the contours of the outer ear, with the cable wrapping up and over. We found this design to be very stable, even with vigorous movement.

However, the key to both comfort and sound is the eartip seal. We spent considerable time testing the various included tips. For us, the memory foam tips provided the best combination of comfort and passive noise isolation. Once warmed by body heat, they expand to create a near-custom fit within the ear canal. This secure fit is the foundation of the IEM’s performance. The detachable MMCX connectors are another pro-grade feature. They click into place with a firm, reassuring snap and allow for easy cable replacement or upgrades down the line, dramatically extending the lifespan of the IEMs. The quality of the included silver-plated audio cable is also noteworthy; it’s supple, resists tangling, and exhibits very little microphonics (cable noise).

The Reality of Passive Noise Isolation

This is perhaps the most critical aspect to understand before purchasing these IEMs. The product description correctly labels them as “Noise Isolating,” but this is achieved passively, not actively. There is no electronic circuitry to cancel outside sound. The isolation is created purely by the physical barrier of the eartip sealing your ear canal, much like a high-quality earplug. As one sound engineer rightly noted in their user feedback, if you don’t achieve a proper seal, “you can hear almost everyone and everything going on around you.” We can confirm this finding entirely. With a poor fit using the wrong-sized silicone tip, ambient noise from a busy office was still clearly audible.

However, when we switched to the correct size of memory foam tips and inserted them properly—compressing the foam, inserting the IEM, and holding it in place for a few seconds as the foam expanded—the results were dramatic. The outside world faded away, and ambient noise was reduced by a significant margin, easily enough to focus on a monitor mix on a loud stage. The lesson here is crucial: the performance of the BASN Metalen is directly tied to the user’s willingness to experiment with the eartips to find a perfect seal. Those expecting the silent void of active noise cancellation will be disappointed. But for the musician who needs to block out the stage wash while hearing their mix with clarity, the passive isolation, when fitted correctly, is highly effective. Check the latest price and see if this fits your needs.

What Other Users Are Saying

Synthesizing feedback from other users often paints a clearer picture, and our findings align closely with the general sentiment. There is widespread praise for the physical product, with one user—a self-described veteran sound engineer—joining others in lauding the “pure premium” build quality that extends from the metal earpieces to the cables and generous accessory set. The sonic performance is also frequently highlighted, with many forgetting “just how good WIRED in-ear headphones sounded” until trying the BASN Metalen.

The most common point of contention, however, revolves around noise isolation. The critical feedback from the engineer who found the isolation lacking in a coffee shop is a vital piece of context. It underscores the point we discovered in our own testing: these are passive isolating IEMs, not active noise-cancelling headphones. Their effectiveness is 100% dependent on the seal achieved by the eartip. This feedback is not so much a flaw of the product as it is a crucial clarification of its function. For users who take the time to find the right fit, the isolation is substantial; for those who don’t, the experience will be underwhelming. It serves as a valuable reminder to manage expectations and understand the technology you are buying.

How Does the BASN Metalen Compare to the Alternatives?

The BASN Metalen 4 Drivers In-Ear Monitors Headphones offer a compelling package, but they exist in a crowded market. Here’s how they stack up against three notable alternatives.

1. Xvive U4T9 Wireless In-Ear Monitor System

The most significant difference here is the technology: the Xvive U4T9 is a complete wireless system. It’s designed for the performer who requires total freedom of movement on stage and wants to eliminate the tether of a cable. While it includes a pair of T9 IEMs, the primary investment is in the wireless transmitter and receiver pack. This is the ideal choice for energetic lead vocalists or guitarists who cover a lot of stage. The trade-off is often a higher price point and the potential for wireless interference, though systems like Xvive are known for their reliability. If your main priority is untethered mobility, the Xvive system is the clear winner; if you prioritize pure audio fidelity and durability for a lower cost, the wired BASN Metalen holds the edge.

2. BASN Bmaster Triple Driver IEM Headphones

Staying within the BASN family, the Bmaster is a compelling alternative for those on a slightly tighter budget. The key difference lies in the driver count: the Bmaster features a triple-driver hybrid setup (one dynamic, two balanced armatures) compared to the Metalen’s quad-driver configuration. This means the Metalen can dedicate two dynamic drivers solely to low-end reproduction, resulting in a potentially richer and more impactful bass response. The Bmaster is still a phenomenal performer and a significant upgrade from basic earbuds, but the Metalen offers that extra layer of sonic detail and low-end authority. If your budget can stretch, the Metalen’s quad-driver setup is a worthwhile upgrade; if not, the Bmaster is an excellent and highly capable alternative.

3. BASN Bmaster Triple Drivers In-Ear Monitor Headphones

This version of the Bmaster presents another subtle but important choice for IEM aficionados: the connector type. While our reviewed Metalen and the green Bmaster use the common MMCX connector, this black Bmaster model utilizes a 2-pin connector. The choice between MMCX and 2-pin is a long-standing debate in the audio community. MMCX connectors offer a swiveling connection which many find convenient, but some users worry about their long-term durability. 2-pin connectors are generally considered more robust and less prone to connection issues over time, though they don’t swivel. If you prioritize maximum long-term durability and plan on swapping cables frequently, this 2-pin Bmaster might be a more appealing choice than its MMCX-equipped siblings.

Our Final Verdict on the BASN Metalen 4 Drivers In-Ear Monitors Headphones

After extensive testing, we can confidently say that the BASN Metalen 4 Drivers In-Ear Monitors Headphones represent exceptional value in the world of professional audio. They deliver a potent combination of robust, premium construction and a detailed, powerful sound signature that is perfectly voiced for musicians. The quad-driver hybrid system provides the deep bass needed by drummers and bassists without sacrificing the midrange clarity required for vocals and guitars. The all-metal build and generous accessory package, including two high-quality detachable cables, are features typically reserved for IEMs costing twice as much.

The only significant caveat is the nature of its passive noise isolation, which requires the user to find the perfect eartip fit to be truly effective. This is not a flaw, but a characteristic of the technology. For the musician, engineer, or audiophile willing to spend a few minutes finding that perfect seal, the reward is a rich, immersive, and isolated audio experience. If you are looking for a serious upgrade to your stage or studio monitoring setup without breaking the bank, this is an outstanding choice. We wholeheartedly recommend it as a top contender in its class. For those ready to experience a new level of audio clarity in their work, you can find the best price and order your pair today.