The Secret Behind the Incredible Sound Quality of UE FITS

· custom fit · fits
At Ultimate Ears, we take sound quality seriously. The custom fit of UE FITS creates immersive music experiences with our perfectly tuned 10mm dynamic driver and passive noise isolation.

At Ultimate Ears, we take sound quality seriously. But how does UE FITS create immersive music experiences? It starts with a high-quality, perfectly tuned 10mm dynamic driver and fully comes together through the groundbreaking instant custom fit.

The FITS Sound Signature

If you look at a spec sheet for a pair of earbuds, you’ll see a lot of numbers corresponding to technical stats like frequency response and distortion level. Most earbuds from reputable companies cover a frequency range of about 20-20,000 Hertz—that’s the average spectrum of human hearing, and covering it is the absolute minimum a set of earbuds should do. Most earbuds also feature very low distortion levels, so it’s not usually a differentiator between different models.

Instead, it’s best to focus on the description of the sound signature. Each model of earbuds on the market has a different sound signature. Some earbuds lean into heavily colored sound signatures—namely, boosted bass or middle frequencies—in the same way some food and drink products add sugar or salt to make their food taste better.

UE FITS takes a different approach to its sound signature. Our goal is to faithfully reproduce music as it was intended to be heard by those who recorded, mixed and mastered each song. With that in mind, we tuned FITS’ 10mm dynamic driver (more on that later) to have a full, detailed and clear tone. To us, that means tight, well-defined bass, clarity through the mids and good high-frequency extension.

The result is a very full, broad sound that has enough power in the low end to make you feel the bass without overpowering the rest of the sound. Striking that balance was very important to us, and it’s a big part of the FITS experience.

Of course, not everyone is going to have the same sonic preference. That’s why FITS comes with a free smartphone app that enables you to adjust the EQ of your earbuds. Using our app, you can select from a variety of presets including spoken word, bass boost and bright settings. You can also personalize your sound further by tweaking any of our presets.

When it comes to personalizing the EQ of your FITS via our app, there’s one thing to keep in mind—proper EQ is as much about cutting as it is about adding. Most people go straight to boosting frequencies they want more of, but cutting the opposite frequency can often give you a cleaner, clearer sound.

Achieving The Best Sound With FITS Drivers

The drivers used in earbuds are just like the speakers in any other sound system. There are many different types and sizes of drivers, but for UE FITS, we opted for a single high-quality 10mm dynamic driver because it offers excellent sound quality while reducing size.

Most consumer-grade earbuds have a single dynamic driver, like FITS. The thing about multiple drivers—even though they produce stellar sonic quality—is that they would add to the size and cost of UE FITS.

When we build earphones and in-ears for CSX and PRO, each set’s balanced armature drivers are manually placed depending on the mold we received from our Fitkit or from the customer’s audiologist. With FITS, we wanted to keep the size small while delivering the best possible audio experience. The 10mm dynamic drivers are perfect for that.

How Custom Fit Impacts FITS Audio Quality

UE FITS’ 60-second custom fit provides incredible all-day comfort, but it also helps create an immersive, high-fidelity music experience.

Our 10mm dynamic drivers don’t technically require as tight a seal as smaller drivers, but FITS provides one anyway. The instant customization of FITS—the way it molds to your ears—seals in what you’re listening to far more effectively than non-custom earbuds.

Bass is especially famous for escaping the ear canal in non-customized earbuds. That’s one of the reasons some brands boost the bass frequencies in their products—they’re trying to compensate for a wildly imperfect fit. With UE FITS, the bass stays in your ears, where it belongs. As a result, we can provide a flatter, truer frequency response that allows all the little details of the music to shine through. And, if you still want more bass, you can personalize your FITS’ EQ in the UE FITS app.

The perfect seal of UE FITS also means a bigger surface area contact with your ears. The more of your body that comes into contact with your earbuds, the more you’ll be able to feel the music. It’s the same feeling as putting your hand on top of your speaker system while a record is playing. The added surface area contact of FITS means you’ll be able to feel the bass in your chest—something you probably didn’t think was possible with earbuds.

The customized fit of UE FITS has another major benefit—passive noise isolation. Earbuds that are properly formed to your ears are extremely effective at blocking out ambient noise. You can listen to your music at lower, safer volumes instead of cranking the volume to compete with the outside noise of the coffee shop or busy office.

Other earbuds either have rubber tips in a few different sizes that kind of squish to form to your ears or are hard plastic. In other words, limited passive noise isolation, if any at all. Some brands incorporate active noise cancellation (ANC) to reduce ambient noise. But ANC isn’t the best choice for audiophiles because, by its nature, ANC headphones and earbuds add distortion to music.

Click here to learn more about ANC and how it stacks up to passive noise cancellation, but the gist is that ANC distorts music. ANC works by creating an equal and opposite noise that cancels out ambient noise around you. In other words, it phases out certain frequencies, which distorts the music you’re listening to.

Additionally, our design helps prevent the occlusion effect—the feeling of being underwater or having a plunger in your ear. It’s caused when your ears are completely blocked up, and it’s an unpleasant sensation. Our team has accounted for this by including proper ventilation in our earbuds, earphones and in-ears. A little ventilation won’t let the bass frequencies escape, nor will it let much outside noise in. It will, however, keep you from experiencing the occlusion effect so you can fully enjoy immersive music experiences with your FITS.

We avoid that with FITS, CSX and PRO by including proper ventilation in our earbuds, earphones and in-ears. A little ventilation won’t let the bass frequencies escape, nor will it let much outside noise in. It will, however, keep you from experiencing the occlusion effect so you can fully enjoy immersive music experiences with your FITS.


Are you ready to try UE FITS? We offer a perfect fit guarantee and have a 30-day no-questions-asked return policy so you can try FITS risk-free.

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