IMR Acoustics R1 – unusual ceramic/beryllium hybrid with bags of tone

Pros:  Smooth and organic sound signature, good all metal build, serious bass prowess, nice texture and weight to the sound, smooth and clear treble, very coherent and musical tuning, multiple tuning options with filters, capability to open up the soundstage with the open/closed port mechanism

Cons: Not massive amounts of micro-detail, could potentially be a little bass-heavy for some (can be mitigated slightly with filters), not massively sparkling in the treble

Price: £500 (IMR Acoustics)



These IEMs were provided on a loan basis by Bob at IMR Acoustics for review purposes. There was no financial incentive for writing this review, and the gear was returned to Bob/IMR once the allotted time period was up, so the opinions expressed below are 100% my own.

Introduction (and the elephant in the room)

IMR Acoustics are a new company, founded in 2017 by Bob James, formerly the head designer and forum “face” of Trinity Audio. For people who are aware of Trinity Audio, this will probably be quite a polarising fact – I won’t go into details here as this should be past history, but I will just say that after speaking to Bob via email prior to agreeing to do this review, he has explained a few things about the direction he wants to take with IMR and I’m comfortable to review these as a “new start” for a new IEM manufacturer.

Unboxing and aesthetics

As these are a pre-production sample, no retail packaging was available at the time I was sent these IEMs, so I just received the IEMs and a sample cable, filters and tip selection. IMR have since confirmed that the expected loadout for the R1 once it hits the shelves is likely to include a case, single and double flange, whirlwind wide bore tips, foams and potentially some hybrid tips as well. Please note that in the pictures attached, the cable and filters shown are not the “final” production items, although the tuning is final so the filters will behave in the same manner on the finished article.

As for the IEM itself, the design is pretty unusual, and quite strikingly industrial. The main body of the IEM is angled backward from the central 2-pin “stalk”, and is reasonably slim, with a solid circular disc on the outside of each IEM that covers the in-house open/closed venting solution. The IEMs are solid metal (aluminium, I believe), and feel well machined and constructed, exhibiting a nice solidity to the design without too much weight. The shape is different from the usual teardrop or cartridge designs on the majority of IEMs out there, and due to its relatively small dimensions, maintains a nicely sophisticated look when worn.


Once in-ear, the R1 are a very ergonomic and comfortable design. The main bore of the IEM is angled in to the ear, flowing the natural shape of the ear canaland allowing for the main body of the IEM to sit flush in the bowl of your outer ear. The rounded edges to the shell design help here, with no obvious pressure points being generated where the shell contacts the surface of the ear, making for a very comfy fit.

As you would expect from an IEM in this sort of “mid-fi” price bracket, the R1 are designed to be worn over-ear. One point to note – the pins on the IEM are a standard 2-pin CIEM style cable socket, but are mounted at 90 degrees to the “normal” angle, so for users who wish to cable roll, please bear in mind that you will probably have to adjust the memory wire portion of any cables (If they have them), and pre-formed/heat shrunk ear guides may not work. For more this isn’t a problem, and I did the bulk of my listening with an 8-braid SPC Litz cable from the Trinity Audio Hunter I have in my collection, as the cable matches very nicely in terms of ergonomics with the overall design of the R1, which shares a similar shape and fit in the ear to the Hunter.

Audio quality

The R1 have an unashamedly “old school” feel to the tuning, with the aim to reproduce a more analogue and musical tone to the sound rather than shooting for absolute studio reference. For me, this is a very good move, with the R1 producing a weighty and supremely musical sound, heavy on tone and enjoyment over absolute detail, and feeling no poorer for it. The 13mm beryllium driver kicks out a powerful and punchy lower end, and the ceramic driver blends in beautifully as the sound climbs up the frequency response to produce a clean and clear midrange and extended but never sharp top end. In fact, the stated extension goes right up to the top end of the official “Hi-Res” certification scale at 40kHz, which is obviously too far for my merely human ears to discern, but should keep any canine IEM wearers in raptures with their latest dog-whistling chart toppers.

Joking aside, the extension on both ends of the spectrum is top notch, with the R1 keeping level through the mid-bass down into true sub-bass territory, the big Beryllium dynamic just digging deeper and deeper without any hint of bottoming out. In terms of tightness and overall detail I have heard better dynamic bass (CA Vega, take a step forward), but in terms of absolute depth of sound, the R1 can definitely compete with anything I have heard in the in-ear market at the moment.

The overall tuning before you start playing with the filters is somewhere approximating an L shape, with the mids and treble both sounding smooth and clear, but not quite as weighty as the bass. Playing with the filter options (a very sensible five in total, all with a noticeable effect on the sound) allows some good tweaking of the tuning to shape the base tuning slightly more to your own preference. This feels like an evolution of Bob’s previous work with Trinity, with the underlying tuning feeling far more cohesive and measured overall than IEMs like the Hunter, starting with a better balanced baseline to mount the tuning offensive from. There are no unusual spikes or hotness in the mid/treble transition, and the emphasis in the higher end is on a clean and strong reproduction rather than a more stylised “fizz” or sparkle. Don’t get me wrong, these certainly aren’t dark IEMs, but there is more of a natural feel to the sound, which fits in nicely with the overall more analogue and organic tuning that was obviously being aimed for.

As this is a filter based IEM, rather than the usual categories, I am going to concentrate on describing the overall sound through my two favourite filters, the green and purple.

Purple filter / no damper (mildly L-shaped sound)


Starting with the sub-bass, the R1 produces a nicely textured sound in the lowest reaches through the purple undamped filter, with plenty of volume and quantity. As previously stated, it extends as low as anything I’ve heard, taking the subsonic “Why So Serious” from The Dark Night soundtrack and turning it into a veritable earthquake in between the ears. Moving up into the mid-bass, the R1 shows a good visceral impact, slamming hard when called on, again using the big Be driver to good effect. Despite the impact, the overall bass presentation isn’t boomy or flabby, and while it may be a little on the heavy side for some in this configuration, it still feels well controlled, with only a minimal sense of overshadowing the midrange on really bass-dominant tracks.

In terms of balance in the lower range, there is a good blend between sub and mid bass which feels almost flat in the transition, portraying a nicely rounded note presentation. The DD used is no slouch, but by the same token there is no spectacular speed to proceedings, leaving a nicely organic feeling to the note decay. On more busy tracks, the bass doesn’t feel hurried, however, treading a nice line between big and overly bulky. There is no getting away from the fact these 13mm drivers can produce a big physical slam when needed, with plenty of bass presence. This is definitely not an anaemic or analytical sound, lean much more towards warm and musical (think Campfire Audio rather than Sennheiser HD800)


The midrange is very organic feeling, with a good timbre to male vocals. It is reasonably well detailed, but not overly crunchy or vivid, and actually feels quite balanced in this region. Compared to some of the previous Trinity models I have heard, this is a very “mature” tuning, with no audible spikes in the range to add vividness or artificial detail, instead relying on the resolving power of the underlying drivers to bring the music to the fore. These IEMs will not be described as detail monsters with this filter, but at the same time don’t feel overly veiled or lacking, with a nice sense of clarity.

Listening to the upper mids, vocals feel quite forward but again, not edgy or over-sharpened, with no obvious sibilance or shrillness unless it is unavoidably baked in to the DNA of the track you are listening to. Stringed instruments sound phenomenal – the ceramic driver adds plenty of room noise and retrieval of detail from up high to complement the richness of the midrange, and gives a warmly organic texture to cello and violin. Firing up some 2Cellos, the R1 handles “We Found Love” in as enjoyable a manner as I’ve heard. Maybe not the most technically mind-blowing, but when music just sounds right, I tend to stop worrying about any microdetail I may have missed along the way (don’t tell anyone – I may lose my audiophile member’s card if that gets out!)


The highs through the R1 in this configuration sound as smooth as glass, with none of the trademark Trinity “glare” from the later models of the Phantom range, nicely extended without feeling sharp. I never managed to hear the Delta or Icarus models from Bob’s previous employers, but this feels like the treble tuning that the other recent models would have benefitted from. Whether it is simply a different approach ti tuning on this new venture or the capabilities of the ceramic driver I couldn’t possibly say, but one thing I can say without hesitation is this is my favourite treble tuning from anything Bob has designed so far.

Green filter / black damper (mid-forward sound)


In comparison to the purple filter, there is less quantity on display here, the black damping foam taking some of the overall quantity away but still leaving a nicely capable and certainly not bass-shy tuning behind. Mid bass still carries plenty of presence, with a good level of impact but less overall power. I suspect (without graphing them) that the increased midrange emphasis felt in the higher ranges is mainly due to the balancing effect this filter has on lower end presence rather than a “boost” in the midrange.


With this filter, the midrange has a slightly less rich and organic tonality (due to the lower bass presence and attendant decrease in warmth), but is pushed further forward in both quantity and position on the stage as a result. There is a payoff to this midrange boost, with the R1 exhibiting a slightly less “natural” tone to the presentation. In this configuration, the vocals are pushed forwards towards the listener, which has the effect of pulling the other mid range instrumentation into the hole they leave behind slightly behind them, in an almost W shaped tuning reminiscent of the Campfire Audio Dorado. Guitars feel a little thinner, but the payoff is a little added edge and crunch, with the lower relative bass presence allowing the edges of the notes to stand out more in riff-heavy tracks.

Moving through to the upper mids, the presentation is still not sibilant despite the additional presence. Vocals sound clear and nicely weighted, with a slight boost in perceived clarity and a little more room to breathe in the stage overall. Once point to note is that the upper mids can occasionally overshadow the transition into the treble, giving the effect of standing a little in front of the treble notes like cymbals. This isn’t a major consideration, and in the main, the R1 presents a nicely separated and very clean audio image with these filters, and in fact these became my “go to” setup by the time I had to return the demo pair to Bob. Despite the slight loss in naturalness, there is something addictive about the vocal presentation and the way they sit alongside the bass, providing a rich and warmish almost tube-like tone to the sound for most vocal and guitar based music that is very enjoyable. I mentioned the Dorado from Campfire earlier, and I think the tuning of the R1 tends to evoke the same sort of musical and organic tone that the Campfire models are known for, without straying too far into Ken Ball’s sound signatures.


The treble with this filter is the least affected frequency range, sounding pretty much the same as through the undamped purple filters.

Separation and imaging

The R1 are highly capable when it comes to separation, and exhibit similar characteristics across all the five filters. On “White Worm” by Marty Friedman, the drums spread out behind the head well, pulling a nice crisp image and panning across the back of the skull with distinct impacts, the separate tom tom hits rolling around like thunder behind the eyes. The multiple layers of instrumentation on this tune gives the dual driver setup a nice test, which it passes well – each layer of the wall of sound is nicely marked out, not leaving a huge expanse between each slice of sound, but still remaining crisp enough to be easily distinguishable.

As far as imaging goes, the R1 provide a nice sense of width, and reasonable depth. There is a strong (if not laser-like) sense of instrument placement, with the soundstage feeling more oval than spherical.

Effect of the open/closed port

The most unique aspect to the R1 design is the addition of a rotating disc on the back of each IEM shell, which allows the IEM to be changed from fully closed to a semi-open setup by rotating the back cover to expose the four ports drilled into the back of the driver casing. These ports are covered in a find mesh and don’t actually leak much sound, so this doesn’t expose the delicate innards to any more risk of damage when opening the port, and is pretty simple to change on the fly without having to remove the IEMs.

In operation, this is a subtle effect, most noticeably dropping a little bit of bass pressure in the lower mid-bass and sub bass regions, in exchange for a little more feeling of air in the staging. It doesn’t suddenly explode the soundstage 3 feet out of your head in both directions, but there is an almost palpable feeling of pressure release, and the music just seems to relax its shoulders a little and push out a few more inches either way. There isn’t any massive sound leakage as a result of the port opening, but it is an interesting effect. Outside noise is slightly more audible as well (usually drowned out by the music playing), so can be useful in environments where you need to kill your music but don’t want to pull your buds out of your ears to talk to someone. This works best in tandem with the filters, allowing a little bot of extra tweaking to the base tuning of each filter to either lock in or tone down the bass, and air out or condense the sound slightly.

Subtle as it is, I think this is a genuinely useful innovation, and ended up using it a lot more than I thought depending on where I was listening to the R1 – ports closed for bass slam and isolation on my busy public transport commute to the office, and ports open and lower volume when chilling out in bed at the end of a day (and still not enough leakage to disturb my other half). This is evolutionary rather than totally revolutionary, but definitely adds something to the overall sound, so kudos to Bob and IMR for thinking outside of the box on this one.


Campfire Audio Andromeda – The Andromeda is one of the current co-flagships of the Campfire Audio range, and is one of the most highly regarded $1k models currently on the market. I have chosen this comparison due to the similar approach to tuning shown in both models, with an emphasis on tone and organic reproduction of sound.

Starting with the bass, the Andromeda has significantly less presence vs the R1 using the purple filters, with the IMR model carrying a fair bit more weight in the sub and mid bass ranges. The notes are also thicker on the R1, with the Andro carrying  as much or more overt detail at each interval as the sound rises through the mid and treble ranges, but in a slightly thinner presentation. The lack of bass weight gives the Andromeda a more neutral feel to the presentation, with the notes swooping round a stage with more fell of air due to the sizing. With regards to clarity, the Andro pulls ahead slightly due to the lightness of its notes, but in contrast the R1 presenting a more convincing sense of depth with its weightier presentation as music pans around the stage (a good track to highlight this is “We Found Love” by 2Cellos, which has a swooping cello run around the 1.50 mark in the left ear that feels a little more fleshed out on the R1).

Opening the ports on the IMR model makes things a little more competitive in regards to air and space in the soundstage as the bass pressure levers off slightly, allowing the midrange a little more freedom to move. The Andro is still ahead in this regard, although the gap is comparatively smaller, with the Andro just feeling a shade more clear and refined.

Build quality is again similar between the two, with the unique industrial design of the Andromeda just nudging ahead of the R1 – as this is a pre-production model, the final article may be a little closer overall. IN terms of comfort, both IEMs sit in the ear well and provide good levels of isolation, with the Andromeda providing slightly more due to its sealed aluminium shell compared to the ported and vented design on the R1.

In terms of power requirements, the Andromeda is considerably easier to drive, requiring less power to reach a good listening volume. It is more sensitive to impedance of the source, giving slightly different levels of bass and treble depending on the DAP/source being used. The Andromeda also hisses significantly more than the practically jet black R1 on most of my music sources.

Overall, the Andromeda provides a more balanced and refined sound than the R1, which you would expect at approximately twice the price. Both IEMs share a nicely musical take on sound reproduction, and while lower, the R1 certainly doesn’t feel a million miles away from the Andro in terms of overall quality, and is certainly pretty close in terms of sheer enjoyment factor.

Astell & Kern / Beyerdynamic AKT8IE MkII – the AKT8IE Mk2 (hereafter referred to as the T8IE) is an Astell & Kern collaboration with the German company Beyerdynamic, and utilises their proprietary Tesla-coil technology to provide a single dynamic driver flagship for the current A&K in-ear range. Both IEMs are tuned with a more musical tilt rather than purely analytical, and the T8IE are more closely priced to the R1 in the current second hand market at around £800.

Starting with the bass, the T8IE has more mid bass focussed sound compared to the equally mid and sub centred R1, which can occasionally make the A&K model feel a little heavy or congested on some busier tracks like “Sound Of Madness” by Shinedown. The T8IE is comparable to the R1 in terms of physical impact and slam factor, keeping up well with the heavy drum impacts of the aforementioned Shinedown songs and other rhythm heavy tracks.

Moving on to the mids, there is a crisper sense of “attack” on guitar based music with the T8IE, the midrange feeling slightly thinner and crisper overall, with guitars jangling a little more cleanly in the listener’s ear but carrying three dimensionality and weight. Vocals feel textured and impassioned on the T8IE, competing well with the organic sound of the R1. The slightly less weighty presentation also adds to a slightly better sense of separation in this range, with the T8IE feeling easy to pick out the twin guitars of some of my more intricate rock tracks from bands like The Darkness or Shinedown with a slightly more clinical execution. With tracks like “You’ve Lost That Loving Feeling” from the recent Elvis collaboration album with the Royal Philharmonic, there is slightly more rasp in the vocal delivery with the T8IE, which is great for finding the emotion in a track. On the flipside, the T8IE feels slightly less balanced in comparison to the green filtered R1, with the vocals sitting a little behind the more pronounced midbass, and the sound carrying more impact but feeling a little less rounded.

Treble is similar on both, with the R1 carrying a little more weight and feel of extension in comparison to the sharper but thinner T8IE. Detail feels slightly higher in AK, but not huge – the R1 again feels more analogue and rounded in comparison, highlighting the trade-off between ultra detail and tone/balance that separates these two IEMs.

In terms of soundstage, there is slightly less of feel of depth and warmth on the T8IE in comparison to the R1 with the green filters (my favourite configuration). The T8IE actually feels more forward overall than the more laid back IMR model, pushing the listener a little closer to the music than the more laid back sound the IMR model is going for.

The T8IE packaging is top notch, so the R1 would have to pull something seriously top notch to compete with the A&K model here. The T8IE is also more efficient, being considerably easier to drive and scaling well with higher end gear. Build quality is similar between both, with the T8IE winning the ergonomics battle with a supremely comfortably shell shape that just disappears into the ear for extended listening, but loses out being a metal coated plastic IEM to the sturdier and more robust feeling solid metal shells of the R1.

Overall, the T8IE presents a nicely emotive sound, with slightly more refinement in terms of audible detail and finesse than the R1, but can come off a little thinner sounding and less flexible than the more tunable IMR model, and loses out a little in terms of absolute extension and bass tuning over the more capable feeling IMR dual dynamic setup. Preferences here will come down to if you like your sound a little crisper and more obviously detailed, or whether you prefer a fuller sounding and more tube-style rendition of your favourite tracks – neither would be a poor choice for most people.

Periodic Audio Be – this is the flagship model from the new Periodic Audio range, and is another dynamic driver model currently on the market with a beryllium diaphragm. It retails at around the $300 mark at present, so is roughly half the price of the R1.

Diving straight in to the sound, “We Found Love” by 2Cellos is first up. The initial impression of the sound produced by the Periodic flagship is of a less weighty overall tuning, with more crispness on the edge of notes and a slightly airier, more V shaped sound. The Be has a more oblong soundstage presentation than the R1, with less obvious depth. In terms of detailing, the additional crunchiness and crispness in the high mids and treble lead to a better perception of detail compared to the rounder R1.

With regards to the bass, both beryllium drivers can dig deep when the track requires it, and have a similarly low extension. The Be has more of a sub-bass tilt to the tuning in comparison to the more evenly distributed lower end of the R1. The additional mid-bass presence adds a little more warmth to the R1 with the filters I prefer in comparison to the slightly colder and more sub-oriented Periodic model.

Listening to something like “The Weekend” by Brantley Gilbert, the R1 again gives a slightly fuller but less crisp sound. The midrange is more forward on both filters mentioned above, giving a more analogue presentation, the less V shaped tuning and additional warmth from the mid bass giving a more vinyl-sounding tone to the music. The R1 also shows a little more in the way of directional cues on the drum hits, mainly down to the more 3D staging allowing for a more realistic placement of the impacts. This is a densely recorded song, and through the R1 the layers do feel feel closer together than the more obviously separated Periodic IEM, but this is balanced out by a bigger and wider stage on the R1. The treble is very crunchy and defined on the Be, but feels more smooth and less crystalline on the IMR, carrying more weight. I also prefer the R1 for the vocals on this track, as they add a little less edge to the gravel in Gilbert’s voice and present a more intimate and balanced sound in comparison to the slightly more recessed Be, which tends to add a little grit to the lower end of the vocal delivery here.

Last of the test tracks here is “Big Boys” off Chuck Berry’s last album, and in fairness the R1 presentation could have been made for this song. The IMR model presents the track with beautifully solid drum hits, a thick and jangling guitar, layering the smooth and soulful vocals from Berry and Nathaniel Rateliff over the top of the music seamlessly.  The R1 also conveys a strong image of the  room behind the mic on Berry’s vocals, adding to the “live” style sound. In contrast, the Be gives a thinner and more obviously textured sound, with the blended vocals not sitting quite as forward in the mix. Berry’s trademark jangling guitar riffs sound sharper on the Periodic, with less weight but more edge. The flatter presentation on the Be also gives off less of a feel of the room behind the singer on this track, but that is more marginal than massive. Overall, the Be feels less thick, with the imaging placing more of the music in the middle of the stage, and not pushing it back quite so deep.

In terms of presentation, the Be comes in a simple cardboard box with the IEMs, a small tobacco tin IEM case and some tips, so the R1’s proposed loadout should see it home quite comfortably on this front, if that sort of thing matters to you. The build is also won quite comfortably by the R1, with the Periodic model sporting a functional but uninspiring polycarbonate shell and thin and non removable runner cable, leaving it feel cheap in comparison to the all-metal build and removable cable and tuning filters of the IMR model. Ergonomics are also won by the R1, with a more comfortably and secure in ear fit in comparison to the more traditional “worn down” style of the barrel shaped Be.

Finally, the Be needs less power to drive well, needing less juice to hit maximum capacity than the thirstier R1. Overall, while the V-shape and obvious capability of the Be driver gives it a nicely detailed sound with plenty of low end, the comparatively smoother but more emotive R1 has a bit more for me in terms of tuning and emotional connection to the music to justify the increased price tag, presenting a warmer, thicker and more realistic sound in comparison to the very enjoyable but more stylised Periodic model.

Trinity Audio Hunter – the Hunter is the flagship model from Bob’s previous employers Trinity Audio, and sits in the same price bracket at £500, with a similar all-metal build and tunable filters to tweak the sound. Despite sharing a similar shell shape and tunable build, the two IEMs couldn’t be more different in terms of actual tuning philosophy, so much so it’s actually quite difficult to imagine the same person designed both pieces.

The Hunter are tuned to sound like a classic “audiophile” sound, with super-high detail levels and a taut, punchy bass which emphasises speed and leanness over impact or body. It does this by means of a pretty heavy spike in the high mids/lower treble, giving a razor sharp edge to the detailing and an accompanying heat to the treble which isn’t there in the clean and smooth high end of the R1.

The Hunter does have more filter options (12 in total), but for me only three or four of them actually suit my sonic preferences, so the tweaking potential is similar as some of the Hunter filters can be downright unlistenable with the treble heat they bring. In terms of bass on my favourite filters (gold on Hunter, purple or green on the R1), the IMR model has considerably more body and quantity, making the almost BA-style bass of the Hunter feel quite anaemic in direct comparison. The Hunter bests the R1 in pure speed in the low end, and produces a similar or higher level of texture to things like bass guitar, but lacks the sense of body and physicality of the big 13mm beryllium driver. This lack of body also contributes to the tone of the Hunter, with the hybrid sounding exceptionally cold and clean, in comparison to the warm and chunky IMR competitor. The R1 also has a more even balance between mid and sub-bass, and a stronger extension down into the really low notes as a result, with the Hunter sporting more of a traditional mid-bass “hump”.

The same holds through the mid-range, the Hunter pushing out a far more audible level of micro-detail than the R1, but sacrificing weight and tone in the process, adding a cold and almost hard sheen to the sound. For my personal preferences, I far prefer the tuning of the R1 in this regard. The Hunter also has its major flaw in this area, a quite vicious peak in the higher mid range that can bring some serious heat into play on some of the filters. Once this has been tamed with the right filters then the sound becomes more enjoyable (I found a combination of the Hunter 8-braid cabling with a warmer balanced source like the QP2R brought this more under control) but this sits in stark contrast to the more even tuning of the R1, which is pretty much enjoyable through all the options.

The Hunter is far crunchier with guitar and string instruments, emphasising the edges of notes – this works very well for more sparse acoustic arrangements, where it holds the edge over the R1 if you are looking for technical excellence over tone or timbre, but in most other genres, the warmer and more cohesive tuning of the R1 wins out for me.

Another area the Hunter excels at is imaging, projecting a slightly diffuse but almost holographic sense of space around the listener’s head, placing instruments firmly in space across all three dimensions. The R1 is no slouch here, but the warmer and thicker presentation can lag a little behind the laser-like accuracy of the Hunter in this regard. That isn’t to say the R1 is in any way lacking, but in this regard the Hunter is truly up there with other high end monitors I have heard.

Overall, these two IEMs couldn’t be further apart in the way they are tuned, and the way they deliver the music you listen to. If you are after a surgical and precise sound with less warmth or give than a sack full of ice cold rocks, the Hunter will excel, but if you are after something more forgiving, with a far thicker presentation of note and overall musical balance, the R1 is a clear winner for me here. It serves as a nice reminder that you can reproduce musical in all its technical glory, but sometimes it is more important to capture its soul instead, as that is what makes listening enjoyable.


Price £500
Frequency Response 13 – 40000 Hz
Sensitivity 108 +/- 3dB
Impedance 32 Ohms
Included features Open/closed back porting system, 5 tuning filters
Included cable 13mm Beryllium dynamic driver + ceramic driver (hybrid setup)


Spending some time with this IEM was a very interesting proposition for me – knowing that this is the maiden effort for a new company, but having a fair bit of experience with the designer’s previous tunings and models in his former life left me a little unsure whether to expect more of the same, or something radically different. I’m very happy to report that different is what I got, and I believe this IEM is all the better for it. It shoots unashamedly for a musical presentation, not trying to wow the listener with audio-plankton and micro-detailing so fine only dogs and Superman could hear it in the real world. Instead, the emphasis here is on giving the listener a solid, organic feel to the sound, going for the soul of the music rather than the blueprints.

Despite the more obviously musical tuning, this isn’t an IEM that feels lacking in technicality, with the tandem 13mm beryllium dynamic and the more unusual ceramic driver blending together beautifully to produce the most coherent and balanced tuning I’ve heard from one of Bob’s creations yet (I must admit to never hearing the original Delta, however). It is this sense of balance in the underlying tuning that really elevates this IEM to the next level, allowing the filters and openable ports to make a subtle but audible difference to the sound but still stay close enough to the original balance to never sound overcooked or too far to one extreme. Add in some SERIOUS basshead level low end quantity on tap and a smooth and classy treble without any hotspots, and you have a tuning for people who love their music like they hear it in a dimly lit blues bar, or cranked through their old record deck and their parents’ huge amp. Warm, soulful and just right.

Now for the dose of reality and perspective – this isn’t an IEM that will rewrite the book on technicality, and it isn’t likely to be an IEM that will wow the HD800 and Grado fans of this world. It has its limitations, and in terms of resolution and clarity it is good but not stellar for the price bracket. That being said, there are precious few IEMs in this sort of price and capability bracket that are tuned this way, so if you are looking for something in the mid-fi tier that can blow your mind with bass or charm your ears with their smooth and velvety sound at the same time, the R1 is a strong debut entry from IMR Acoustics, and will definitely be worth checking out once they go on sale.


6 thoughts on “IMR Acoustics R1 – unusual ceramic/beryllium hybrid with bags of tone

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  1. Nice for you that you have a Hunter to compare – as you know, many people, including friends of mine, are *still* waiting for delivery after over a year! But Bob simply walks away and starts making new stuff. Pretty shameful if you ask me, I don’t think anyone should buy anything from him after he failed his customers and also rejects the Trinity models as not what he would choose to make.
    Let down your customers, make stuff that doesn’t live up to the hyperbolic marketing (the pinnacle of what we can do with an IEM? For the Hunter, a hot sibilant anticlimax!) And then go on to make more expensive stuff, in the hopes that people have short memories.
    A clue: they don’t.


    1. Hi there – apologies for the late reply, I’ve been away on holiday. I wrote this review after speaking to Bob over email, and while I was personally OK with what he told me around his relationship (and the ending of it) with Trinity, I was fully aware that some people would have a similar opinion to the one expressed above.

      It is up to everyone to make up their own minds whether they are interested in buying anything that Bob’s new venture offers, and I think he is aware there are some who will avoid his new gear precisely for the reasons you gave above. I wanted to hear the new IEM as the tech intrigued me, but for any ex-Trinity customers out there, it will be down to them to decide whether the venture is worth their cash or not.


  2. Missing a comparison to 64audio U8.
    Being a basshed, who likes velvety smooth, but still nicely detailed mids/highs, I was about to buy either U8 or the AKT8i mkii, when these caught my attention.
    I would appreciate a short shootout between the three?


  3. Missing a comparison to 64audio U8.
    Being a basshed, who likes velvety smooth, but still nicely detailed mids/highs, I was about to buy either U8 or the AKT8i mkii, when these caught my attention.
    I would appreciate a short shootout between the three?


    1. Azel, just for your info, I own a 64 audio U8 and just got a shipping notice for the IMR R1… I’ll be able to give you a comparison between those two at the very least. Though if you’re looking for clean bass, centered mids and highs, the U8 is already a great choice.

      I’ll report back as soon as I have the R1 in hand 🙂


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