ADV Eartune Fidelity U: Sublime Comfort

Pros: Comfortable – Quality silicone – Do not alter sound (save for niche cases)

Cons: Shallow design and small sizing limit compatibility with shallow fit earphones – Steep price



Today we’re checking out a new product from ADV; Eartune Fidelity U eartips.

Born through a Kickstarter campaign back in 2015, ADV, or ADVANCED as they were known back then, stormed onto the scene with the M4. The M4 was a compact micro-dynamic equipped earphone with one of the most badass cables found on an affordable earphone. Since their humble beginnings, ADV have expanded their lineup with noise cancelling earphones, planar headphones, pure-BA monitors, true wireless products, Bluetooth dongles, and various other accessories. The brand is fully-fleshed out with products that cater to everyone from casual scum to professionals.

One of their newest accessories, and what we’re checking out today, is their line of Eartune Fidelity U silicone ear tips. Ear tips are one of the most essential aspects of any earphone, right up there with how well it is tuned. Without a proper seal, no matter how well crafted an earphone is, no matter how ergonomic, regardless of the materials and general quality, it’s going to sound like nails on a chalkboard if you’re not achieving a proper seal.

Packaging for the Fidelity U is simple and clean. On the front in the top left hand corner is the size along with colour coding for easy recognition; orange for large, grey for medium, purple for small, green for extra small. Dead centre, below the cutout for hanging the package on a shelf, is the ADV logo. Taking up the majority of the package are the ear tips set behind clear plastic viewing windows. A large wire frame image of the tip rests in the background. Along the bottom of the package is the model, Eartune Fidelity U, and some design features; elliptical shape and Wide-Exit-Bore opening. Flipping to the back you find expanded descriptions of the previously mentioned design features. This is printed on a perforated panel that can be easily peeled off to access the tips inside. ADV also notes the diameter of the bore opening at 4mm. Tip sizing is repeated down the left side, in case you missed it earlier.

Once I had the tips out and in my hand, I was immediately impressed by the clean moulding of the 100% hypoallergenic silicone. The flange is soft and flexible with a well-defined ridge surrounding the slightly flared bore opening. Despite being quite thin, it feels plenty durable thanks to impressive levels of elasticity. The shaft of the tip is notably thicker with a flared base that helps with installation onto an earphone. That said, the opening is fairly tight so fitting the Fidelity U to earphones with nozzles 6mm in diameter and larger requires some finagling. ADV notes on the product page that these tips are meant to be used with nozzles 4-6mm in diameter, so it makes sense. Once on though, the tips hold firm and I have yet to have them fall off unexpectedly.

I tested the Fidelity U with a number of earphones over the last month, from budget offerings like the KZ EDX and Cat Ear Mia, to more premium earphones like the Fearless S6 Rui and Campfire Audio Andromeda 2020. I have come away quite impressed. The elliptical design means there is a very slight learning curve since you need to install them on the earphone in a way that matches the orientation of your ear canal. I took me a few installations to find the perfect fit, something that was easy to replicate across earphones of various styles and shapes. If the uncommon shape of the Fidelity U has you hesitating on trying a set, don’t worry, they’re not as difficult to use as some are making them out to be. After all, this style of tip has been around for a long time and has been used by big-box store brands like Klipsch and Panasonic. If your average consumer can figure them out, so can you.

Once fitted properly, the comfort levels afforded by the Fidelity U were pretty much unmatched by anything else I have in my collection. They essentially disappear in the ear, and even go as far as to help improve the fit of some ungainly or awkward products like HiFiMAN’s RE2000 and Kinera Freya. Fit is not all positive though. They are not a particularly deep seating tip, and the sizing is smaller than average. In my experience, shallow fit earphones work best with either a long tip, such as the Spitfit CP100, or a wide, shallow tip, like Sennheiser’s bi-flange set. You can find a similar pair included with the M4 and various other ADV earphones. Since the Fidelity U is neither long or particularly wide, even in the largest size, shallow fit earphones can make for a challenging pairing. My ears typically require a medium sized tip, but with the Fidelity U’s obscure sizing, I had to default to large. I would like to see ADV release an extra large size, ensuring all their bases are covered.

ADV claims that the “Eartune Fidelity U tips are acoustically designed to channel sound in the most transparent way with zero compromise in the original sound signature”. For the most part I agree. Comparing them to common tips from KZ, Sony, Spinfit, RHA, JVC, and others, I found the Fidelity U to have little effect on the sound of the earphone being tested. I typically find Sony’s Hybrid and Spinfit’s CP100 tips to increase midbass and add warmth. JVC’s stock wide bore tips often reduce bass and increase midrange and treble presence. KZ and RHA’s tips are similar to the Fidelity U in that they do little to affect sound output, but fall behind on comfort since the silicone used is significantly stiffer. When paired with earphones that ship with uncommon tips, such as an extremely wide bore (JVC Riptide) or extremely small bore (Audiofly AF120), I found the Fidelity U to alter the sound. Such earphones are uncommon and may require modifications to fit the Fidelity U, as was required for the AF120, so they do not represent the typical experience a Fidelity U user will have. One product in particular I found paired amazingly well with the Fidelity U. That was Tin HiFi’s P1 planar magnetic earphones. No other tip I’ve tried with the P1 has done as good a job of softening the brilliance region peak while simultaneously improving low end response. These two were meant to be.

Overall I think the Fidelity U are a phenomenal set of ear tips, though the pricing keeps me from recommending them to all users. 25 USD for three tiny pairs of silicone is a steep ask for your average consumer that looks to spend that much on an earphone with a full accessory kit. In my experience the average consumer is also quite careless with their audio gear, losing tips on the regular when they sloppily cram them into a pocket. Not something you want with a tip that cost as much as your earphones. You can also purchase the Kinera Tyr for between 20-30 USD and those include Final Type E tips in various sizes. Type E tips match the Fidelity U in quality (but fall behind in comfort and sound altering qualities) and typically retail for around 15-20 USD on their own. What I’m getting at is that value is not a strong point of the Fidelity U, regardless of how awesome they are.

As a result I feel the Fidelity U is best purchased by those who are already heavily invested in the hobby, or are planning to be. If you either have a large collection of earphones that benefits from tip variety, have a large collection of tips you are looking to add to, or have skipped the collectible aspect and gone straight for top-of-the-line products and want to stick with the best-of-the-best, the Fidelity U are well worth checking out. For everyone else the Fidelity U lacks value and sits firmly in the exclusive, premium ear tip segment. That said, if the street price drops 5-10 USD I’ll change my tune and recommend them to everyone.

Thanks for reading!

– B9

Disclaimer A big thanks to John with ADV for reaching out to see if I wanted to review the Eartune Fidelity U, and for arranging samples in XS, S, M, and L sizes. The thoughts within this review are my subjective thoughts based on time spent using the Fidelity U with a variety of earphones. They do not represent ADV or any other entity. At the time of writing a pack containing 3 pairs of same-sized tips could be picked up for 24.99 USD. You can check them out here;

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