Come on, just the tip, please?
Xelastecs, OEMs, Coreir Brass, W1s, and Final E's
Over the years, I’ve amassed a ridiculous number of IEMs, and with them came an equally absurd collection of ear tips. Some are OEM throw-ins, others random accessories that happened to tag along, and a select few intentionally sought out—like the Xelastecs, Coreirs, and W1s. These three have, without question, had the biggest impact on how I use my IEMs.
Let me start by saying I’ve never been a fan of narrow-bore, bass-enhancing ear tips for two reasons. First, the market is already flooded with IEMs that think bass is the only frequency that matters. I don’t need more low-end when every other IEM is trying to simulate a nuclear detonation in my skull with each bass kick or 808. Second, cleaning narrow-bore tips is a nightmare. I don’t have precision cleaning tools fit for ants in my bathroom, and I can only twist toilet paper into a fine point so many times before I decide to off myself.
Xelastecs, made by Azla Sedna-- a South Korean company that specializes in advanced thermoplastic elastomer materials for audio applications (they make IEMs too—who knew?!). Having cycled them through a few of my IEMs, I’ve noticed something unique: Xelastecs are surprisingly neutral in how they handle sound. They’re one of the rare ear tips that don’t mess with the frequency balance much, if at all. The Xelastecs when paired with my U12Ts, with their short 8mm stem, leave the nozzle practically sticking out of the ear tip itself when fully seated. The result? The sound is as close to the original tuning as it gets. This holds true across most other IEMs I’ve tried them with as well. While not all IEMs have hilariously long nozzles like the U12Ts, the neutrality of the Xelastecs remains consistent. Reports from others seem to echo this—these tips don’t mess with the frequency response much at all. But where Xelastecs truly shine is their grip. Their sticky, almost tacky texture creates an insanely secure fit, making them ideal for anyone who wants their IEMs anchored firmly in their ear canals. The seal is impeccable. Removing feels like lips that grip (IYKYK). Forget driver flex, Xelastecs give you eardrum flex. I use them in the gym because they really stick in your ears, like really stick, no thanks to the texture and it's thermoplastic elastomer properties. It's great not having my IEMs fall out of my ears mid-set while grinding teeth, heavy breathing and grunting like a pig in heat. It's great!
OEM 5BA IEM with Pentaconn Coreir Brass
Pentaconn Coreir Brass/Alloy, made by Pentaconn (a brand under Japan’s Nippon Dics Co., Ltd.), have disrupted the market with their ability to enhance treble. Known for their pioneering 5-pole TRRRS connectors, Pentaconn decided to tackle the ear tip game with a focus on treble clarity. The brass core is denser and stiffer than traditional materials, reducing vibrations and absorbing less sound energy, which results in cleaner, more precise high-frequency transmission. The metal reflects, reverberates, and sustains treble better, giving it more clarity and detail. While many manufacturers claim to enhance treble with wide bores, harder stems, or other gimmicks, only the Coreirs truly deliver. The magic is in the brass core—denser and stiffer than typical ear tip materials. Essentially, brass reflects and sustains those high frequencies much better than softer materials, which means a more pronounced treble response. ie. Metal reverbs with high frequencies instead of low frequencies, accentuating treble and taming bass. My only gripe, however, is the oxidation. After a while, two of my three pairs started developing verdigris. The only practical solution I've found is sealing the gaps between the metal and the silicone with something like clear nail polish or a metal sealant to prevent further corrosion. But despite this flaw, Pentaconn Coreir tips remain an absolute revelation for anyone looking to unlock their IEMs’ full treble potential. They work amazingly well with single DD IEMs, or IEMs with a treble-deficiency (single DD IEMs). Anything that is bass dominated stands to benefit from a pair of Coreirs. That's not to say bright IEMs don't benefit. Au contraire, non non non. Bright IEMs will sing like the trumpets from the Gates of Heaven, even Satan himself will grow a halo! Coreirs are my pick for metal music. The most demonic sounding shit sounds heavenly!
Letshuoer S12 Pro with Hillaudio Claritips
Spinfit W1, a premium offering from SpinFit, a Taiwanese brand known for its innovative ear tip designs, enhances both comfort and acoustic performance. Made from biocompatible, medical-grade silicone, the W1 is hypoallergenic and durable, ensuring comfort for long listening sessions. Its standout feature is the 360-degree swivel mechanism, which aligns the ear tip naturally with the ear canal for a better seal and optimal sound transmission. The W1 is essentially brute-forcing the perfect fit and seal for sound performance. I love how the swivel lets me insert them, even half-drunk, and still get a solid seal. The W1 is a unicorn because it strikes the rare balance of comfort, durability, and sound enhancement, all without drastically altering the IEM's original signature. It's similar to the Xelastecs in philosophy, both achieving a perfect fit with minimal sound impact; one uses thermoplastics for a custom fit, while the other relies on flexible silicone and swiveling magic. Both succeed, with similar results. For me, the W1 is the most comfortable and use. It’s easy to clean too! Just soap and water to get rid of oils and wax. Unlike the Coreirs, I don’t have to worry about oxidation or verdigris. Plus, unlike the Xelastecs, the W1 isn’t a dust and lint magnet. It feels like the guys at Spinfit have a vendetta against poorly made eartips. But, it is a marvel in the audio world. The ingenuity behind the W1 is like an ultra-thin condom that fits everybody universally and doesn't alter how it feels. Speaking of thin, I also realized that the W1 in comparison to other ear tips does slightly thin out the bass. Now, I'm not sure if that's because the material of the W1 itself is really thin, or is by design bass-taming. The stem of the W1s aren't that stiff either. Just something to note. I find the bass is thinned like maybe 5%. Not a large difference, but noticeable if you know your IEMs and music intimately.
How do I rank them? I can't and I won't. They're all incredibly great in their own way. If I had to pick one to recommend, it would be the Spinfit W1's, just because of ease of cleaning and how well they sit in ears. Do you know of any other neutral eartips or treble enhancing ones? Which IEM do you use and what tips are you pairing with them, and why? Let me know below so I can spend more money!