IEMs, Reviews

REVIEW: IMR R1 Zenith – Big, Bold and Brash

REVIEW: IMR R1 Zenith – Big, Bold and Brash


The standout spec of the Zenith is its massive 14mm dynamic driver, made from a combination of piezo-ceramic and beryllium metal. This is the first time I’ve seen ceramic drivers in an IEM, since ceramic is notoriously difficult to control and is thus usually limited to higher-end desktop speakers driven by very powerful amps. You could say Bob took a real gamble with this driver, but it’s paid off in at least one aspect: bass.

Not only does the Zenith deliver the biggest, most bombastic bass response I’ve heard in an IEM, it’s even bigger than most headphones, basshead cans included. The bass isn’t just big, it’s also fairly detailed, has decent speed for a large dynamic driver (thanks to the Beryllium diaphragm), and extends lower than a villain’s basement, delivering jaw-shaking rumble when called upon (and sometimes even when not). So big is the bass that when anything tries to get in the way of the lows on a track, it gets squashed. 

There’s a part in Heidi Talbot’s soaring hymn ‘Cathedrals’ (0:50) that showcases just how big Zenith’s bass can be. Yes, it overwhelms the mids, almost floods the vocals, but it’s absolutely delicious, especially if you’re a bass addict. Similarly, at the 2:00 mark of Missy Higgins’s ‘Shark Fin Blues’, the sudden rumble takes the song to another level, putting you in a big wide cavern with Missy while the walls and ceiling shake all around you. 

The Zenith is made for big bass and bass-driven tracks, and while I’m not a huge EDM fan, fans of ‘the drop’ will never feel short changed here. More nuanced electronica, like almost any track on Daft Punk’s glorious ‘Random Access Memories’, is highly rewarding as well, as is drum and guitar driven rock like Def Leppard. 

Playing ‘Love Bites’ off Def Leppard’s ‘Hysteria’, the impact and visceral punch of the drums in the intro is palpable, almost better than I’ve ever heard (or felt) from full-size speakers. I’d go as far as to say these are among the best Def Leppard IEMs I’ve heard, purely for their bass impact, something that can’t be said for some of the better-known IEMs on the market (I’m looking at you, Andromeda). 

Pink Floyd fan? If so then you’ll know how easy it is to get the Floyd to sound good, given the impeccable mastering on their albums, but how difficult it is to make them sound great. I wouldn’t say the Zenith aces Floyd, but it renders the drums on The Wall’s ‘Hey You’ so realistically, they’re worth a listen just to hear them on that track.  

If there’s bass in your music, the Zenith will brandish it bigger and bolder than you’ve probably heard it before. If it gets too much, you can always switch to the pink filter to turn it down a notch, or open up the backplate to diffuse the sound slightly and widen the stage. If you’re really not much of a bass fan I’d give the blue filter a try, but be warned – all that magic I spoke of above will be gone, and you’ll be left with a poor imitation of what this unique driver is capable of. 

On the other hand, if you like what you hear and want more of the same, don’t be tempted by the ‘maximum bass’ copper filter. To my ears it makes the Zenith sound thick and one-toned, with bass overwhelming just about every other frequency. It’s not even a case of ‘too much of a good thing’, it’s just too much. 


The Zenith’s midrange is a complete mystery to me. I get that with bass as big and aggressive as it has, something’s got to give. But where I’d normally just say the bass bleeds all over the mids and call it a day, with the Zenith it’s not so simple. 

Meiko’s ‘Playing Favorites’ album, released by Chesky Records and recorded in Chesky’s iconic single-microphone binaural style, is a perfect example of what I mean. On the track ‘Crush’ (a brilliant cover of the original, by the way), Meiko’s impressive vocal range doesn’t seem to be altogether there. I know how that sounds, but believe me there’s no other way to describe it. It’s as if part of her lower octaves just aren’t being conveyed (and yes, I did try this with a few different IEMs, and only the Zenith made her sound as ‘odd’ as she does here). 

Compounding the ‘problem’ is that the instruments on either side of the room are brought far too forward into the mix, and given the Zenith’s flat soundstage (more on this later), they overwhelm the vocals. This track – and album in general – is possibly an anomaly, especially since it’s recorded differently to many others. But it did highlight for me the fact that the Zenith’s mids are doing something strange. 

They can be at the same time very fluid and engaging, and at others grainy and slightly jarring. In Neil Diamond’s tear-jerking rendition of ‘Hello Again’, his gravelly voice is almost perfectly rendered, alongside a clear and realistic piano. But switch to Queen’s ‘Bijou’ and the glare in Freddy’s usually pristine voice is too bright to the point of being distracting. I’d call it ‘shouty’ but it’s not shouty in the way that I know shouty can be. The vocals aren’t thrust at you all at once – parts of the vocal are a bit recessed, while others, like the edges of higher notes, are too forward, almost shrill. Recessed and forward vocals in the same track? Better believe it!

When they’re good, the mids, on the whole, are very good. They’re not the last word in resolution, even for dynamic drivers, but they’re not dull and flat either. Pianos and guitars are vivid, if sometimes sharp. Timbre is better than decent, and vocals are generally clear, but can also be thin, especially on poorer recordings. Depending on your music, you’ll either hear the Zenith as euphonic and engaging, or come away from listening sessions slightly fatigued. 


I’ve read some reviews calling the Zenith ‘bright’, and I get why, but ‘bright’ isn’t necessarily bad. Maybe it’s just me, but I’ve heard great extended treble before (FiiO’s FH7 and Campfire Audio’s Andromeda are good examples), so I know the difference between good ‘bright’ and blowtorch ‘bright’, and the Zenith can, at times, be the latter. Somewhere along the treble graph there’s a peak or two that will leave your ears waving a white flag.

This is not the treble you want for Mozart or Vivaldi. Listening to Max Richter’s re-imagining of Vivaldi’s ‘Winter 1’, the strings sound unnatural to me. Overall the Zenith lacks the cohesion, subtlety and depth to accurately convey the sonic complexity of this piece, and I’d wager most similar pieces of classical music, at least with the black filter.

However, with the right tips (foamies mainly), the worst of the Zenith’s treble brashness can be mitigated. The orange filter will also roll off some of the highs for you. But the best antidote to crazy treble is not listening to music with crazy treble, or music that’s so poorly recorded you have to wonder why anyone would want to put their name to it. The Zenith will do little to hide the flaws in a track, often magnifying them, so bring on the sibilance if you dare, because you’ll hear it in astonishing detail. 

Perhaps I’m being a bit harsh (excuse the pun). The Zenith, especially with the black filter, makes no excuses for being a balls-to-the-wall IEM. Everything it does is unapologetically bold, so it’s probably naïve of me to expect the treble to be any different. Metalheads and those that love guitar-driven hard rock will likely rejoice with all the screeching going on. There’s a lid for every pot, as they say.