IMR Acoustics R1 Zenith Review: A proper upgrade

IMR Acoustics R1 Zenith: A proper upgrade

IMR Acoustics is a UK based manufacturer and founded by Bob, both the owner and the engineer. Their first model was the R1 which was quite successful for its cost-effective performance, as well as featuring a world-first ‘open and close’ vent system with changeable filters. Now IMR announced their second product, the R1 Zenith. It’s meant to be the most ideal version of the R1, achieving the peak performance as well as supplementing the flaws from the original one. Here I’ll mainly be focusing on compare and contrasting between these two IEMs, the R1 and the R1 Zenith.




The packaging and the logo now has a better, more neat looking appearance. Other than the earpiece, it comes in with a 3.5mm cable, a 2.5mm cable, 5 pairs of filters, AV adapter, 4 pairs of silicone tips, a pair of double flanged tips, 2 pairs of foam tips, a shirt clip, and some paperwork.




The earpieces are fully made out of metal and overall have a similar looking as the R1, except with some major changes. First, the color has been changed from glossy gunmetal to matte grey. The previous R1 had a problem where the inner part of the shell would discolor after some time, though this seems to be resolved from the R1 Zenith. Another change is from the drivers. It still uses the 2-Way 2DD system, but now installed with 2nd gen 13mm uprated neodymium motors with beryllium diaphragm + Piezoelectric ceramic drivers.



The port system

The ‘open and close’ vent feature has been changed too. R1 Zenith now uses a screw type system, achieving wider vent area. Compared with the original R1, this type of port system definitely makes the sound difference more drastic and effective.




The stock cable looks almost identical to the original ones yet softer and less resilient. The 2pin sockets are now installed vertically to the earpieces, but there’s a twist – a reversed polarity.

R1 Zenith still uses the standard 0.78mm 2pin termination, though one side has an opposite polarity than the other, just as QDC or Hidition does. The stock cables are made to be matched with Zenith’s polarity, though you’ll need to reform the earguides if you’re trying to use custom cables with these.



Eartips / filter / cable matching

As previously stated, the new port system shows a bigger difference in sound and the same goes for the filters too. The black filter maximizes all frequencies, providing an aggressive, rich, W-shaped sound signature. The pink filter has the same signature as black but with reduced bass. The copper filter recesses highs and maximizes bass, the orange filter features balanced bass/mids with smooth highs, and the blue filter keeps the sound flat and very airy.

The Zenith is more cable-sensitive than the previous one but works out pretty well with various cables. The performance isn’t bad even with the stock cable, so no need to change it unless you know you’ve got a better one. I recommend to pair it up with pure copper cables.



Sound impressions: Bass

The Zenith does an awesome job presenting weight and depth of the bass without getting muddy or loosened up. It is impressive how clear and prominent the bass sounds without overwhelming the upper frequencies. There’s a bit more bass amount than typical slightly-V shaped but less than Shure SE846 or Campfire Vega. The edges of the bass are polished, giving a smooth, analog taste. Now, most flagship IEMs that are well known for its bass performance and are usually equipped with a large amount of bass. The Zenith manages to keep up with such IEMs, picking up all the details to the very low notes, however with just the right amount of bass.

Don’t get me wrong, the amount is plentiful and has a strong and manly rumble to the lows; it just doesn’t get the point where it feels stuffy. I’m quite positive bassheads could also find R1 to be satisfying. What I also love from the bass is its wideness. It spreads out wide without the border (or the edge) of the bass getting vague, making the bass more prominent and full-bodied. It also got great density with that DD-style punch at the lows.



Sound impressions: Mids

The sweet, creamy mids are slightly stepped ahead with a natural thickness. The vocal sounds lively and airy, providing a very spatial presentation which I found to be quite unique. The Zenith does well on both male & female vocals, and I’d say it has that “Multi driver-like” richness but with better coherency. The overall brightness is just about neutral, however the ceramic driver adds a brighter tone to the upper mids, making the female vocals more refreshing. The sibilance section from the frequency is briefly polished, making it non-fatiguing.



Sound impressions: Treble, etc.

It’s easy to think dynamic drivers sound dull on the trebles, but thanks to the ceramic driver Zenith manage to pick up the details with good precision. Highs feel clear, crispy, and does well on expressing the dense texture from treble instruments. It’s visibly brighter than lows or mids, however it won’t be a problem as it doesn’t get spiky. The highs tend to stay transparent without any coloring added to it. The treble spreads wide sideways as the bass did. And with the spatial mids added to that, the R1 Zenith generates one of the finest, largest headroom for an in-ear.



Compared to R1

First off, let’s keep in mind that R1 and R1 Zenith share the same root while the Zenith is just an ultimate form of the original R1 (just like its name). These two IEMs share the same sound factors and characteristics, though the Zenith is improved in every possible way.

Starting from the overall clarity, the Zenith shows wider staging and depth, improved background details and reverbs, separation, and airy upper frequencies. For me, the most impressive difference was the ultra lows. The bass from the Zenith was a lot darker and denser, providing better imaging which strikes right in the middle of the head.




There are a good amount of cases where manufacturers release an upgrade version of the original IEM. However, at least in my case, most of these upgrade models had a different sound factor and signature. It just made me question if it’s really considered a perfect upgrade if the sound has changed while improving the performance.

With the R1 Zenith, IMR managed to boost the performance while keeping the sound characteristics almost identical with the original R1, making it more than enough to call it a perfect upgrade. It’s glad to see them fixing the weak spots from the previous works while they continue to evolve. The R1 Zenith would be a perfect choice for previous R1 owners as well as those who are into rich W-shaped sound signature. 




IMR Acoustics R1 Review: Back to the basics



Thanks to IMR Acoustics for providing the R1 Zenith in exchange for an honest impression/feedback.

I am not affiliated with IMR Acoustics and none of my words were modded or asked to be changed. 

IMR Acoustics R1 Zenith
Reference tuning
Wide sountstage
Wide frequency response
Switchable open-close vent
Exchangeable filters
Stock cables not compatible with other recessed 2Pin sockets
2.5mm cable issue