Sony IER-Z1R Signature Series in-ear monitor headphones

The Sony IER-Z1R Signature Series are neatly packed with a plethora of accessories.

Striking headphones with a fitting unboxing experience

Sometimes you can tell a product is special by the way it is packaged. The Sony IER-Z1R Signature Series in-ear monitors arrived at my desk with a deluxe, jewelry-box-style presentation. I opened the box to reveal two shining silver earbuds, each etched with a striking 3D pattern that gave off a cool mirrorball gleam. They were perched in a softly padded pedestal, above three drawers packed with a generous selection of accessories.

The largest soundstage I've heard from a pair of in-ears

These headphones offer a hearty helping of substance to go along with that style. Sony always aims for a certain sound profile. At CanJam 2019, the head of their Walkman® division, Tomoaki Sato, told me "we deliver a very wide soundfield, with clear sound position."

Well, I listened to the IER-Z1Rs connected to the Sony NW-Z300 Walkman portable music player. These might be the most spacious sounding in-ear headphones I've ever heard. The soundstage extended far from my head, and the stereo imaging within was on-point, too.

On a high-res version of the Sharon Jones and the Dap Kings track "Something's changed," I could pick out the percussion, horns, and keys going left to right. It was as if the band was performing in front of me. I even got a sense of height — with Jones' vocals coming directly from the center, yet just above my forehead. 

This exploded view shows the hybrid three-driver system that delivers an incredibly spacious sound with accurate imaging.

Hybrid driver system for detailed, full-range sound

Inside each earpiece, there is a combination of three drivers, all dedicated to specific frequencies. Sony says they built each from the ground up, but the dynamic driver design might sound familiar if you know Sony's flag-ship over-ears, the Sony MDR-Z1R. The IER-Z1R's driver uses the same high-grade aluminum-coated diaphragms — albeit smaller — to reproduce the bulk of the bass and lower mids. These light, rigid diaphragms start and stop quickly to deliver a tight low-end punch. 

The upper-mids and highs are covered by a balanced armature driver. I heard great vocal presence on that Sharon Jones album; her voice never felt veiled or removed. Strings and cymbals also shimmered with depth and realism, thanks to Sony's "super-tweeter" driver dedicated to the ultra-high frequencies. 

Advanced crossover system

What struck me most about the sound was the overall cohesiveness. It was amazing how effortlessly the IER-Z1R earbuds delivered deep bass right along with the highest frequencies. I noticed no strain or extra resonance.

Turns out this was by design. The advanced crossover system uses super high-grade materials including custom-built film capacitors designed to cut down on distortion. Sony says they put the drivers system through a myriad of tests before they were completely satisfied. Their goal was to deliver a balanced, consistent performance that sounded as if it was produced by a single driver. 

Professional-level noise isolation

Sony built these IEMs (in-ear monitors) so professional musicians could focus on their specific task in a loud stage environment. I can tell you firsthand, it works well in an office setting, too. The IER-Z1R knocked out outside distractions so I could focus on my tunes.

Connects to the balanced output of the Sony NW-WM1Z Premium Walkman high-resolution portable digital music player (sold separately).

A large assortment of ear tips, for better fit and sound

We often talk about fit in terms of comfort. But getting a good in-ear seal has sonic advantages, too. In the bottom drawer of the case, I found 13 different pairs of ear tips — maybe the most I've ever seen.

Sony includes seven sizes of hybrid silicone tips, and six sizes of what they calls "triple comfort" tips. I personally preferred the latter. They were made of a soft, spongy material that helped create a comfortable, secure seal.

Detachable, wraparound cable options

Sony includes two wrap-around-the-ear cables with the IER-Z1R, each used for a different type of connection (more on that below). I had to overcome a small learning curve to get the right fit — you wrap the cord around your ear like you've probably seen musicians and performers do with their in-ear monitors. Once properly secured, they felt like they wouldn't slide around at all, no matter how I moved my head.

Regarding the two types of cables: one has an unbalanced 3.5mm mini plug for connecting to a standard headphone jack on a smartphone or portable music player. These in-ears are efficient enough that you can connect to your phone, but you'll get even better sound with a portable high-resolution music player. In fact, the second cable includes a 4.4mm balanced headphone plug so you make a balanced connection to a compatible amp or high-res portable audio player.