To say I have been impressed with the sound quality of the IMR Acoustics R1 is an understatement and I mean that in the strongest possible terms. These things are absolutely insane to listen to and their ability to adapt and provide real useful interchangeable sound is unmatched.

I have heard hundreds of earphones since starting this site and it is hard-pressed to pick another I like better and yes that includes my own Campfire Audio Andromeda & Vega as well as my Shure SE846. Now I am not saying they are better than those earphones but I think its fair to say they are on a par (sound wise) and their ability to be adapted to a completely different sound and become multiple different sets of high-end earphones in one really stands out.

So where to start in reviewing an earphone that has potentially 10 different sound signatures? Well, to keep things nice and short I am going to give you my impressions of my two favorite modes. To be fair I could happily listen to any of the filters and thoroughly enjoy myself but 2 really stand out for the way I listen.

None of the settings convey a perfectly flat and neutral sound, they are not for critical and technical listening. All have an energy and musicality to them so if you are looking for something flat sounding and studio reference like then I would still stick to the Etymotic Research ER4XR. For the rest of us, people who listen for the pure enjoyment of the music these are far better earphones to live with on a day to day basis.

Copper Filters - In closed back mode (Summary)

In years of working clubs in Shinjuku & Shibuya, Tokyo I developed a craving for insane bass. Mostly from the Industrial Electro and Psytrance genres. No greater a test of sub-bass can be found than from Angelspit and Chaos Royal and with the copper filters on these headphones will melt your brain. There is a copious amount of deep and textured sub-bass which is complemented with a super responsive attack. The earphones sound alive and charged full of energy that makes some similarly priced competition positively flat. These filters really are only to be used with the music that has an enhanced low-frequency demand but they just do it so well. Right now I can't think of a better basshead IEM on the market.

Tamed but still present treble. Lots of detail but not as much sparkle as some of the other filters.

A warmish midrange with lots of clarity and instrument separation. Less energy with the blue filters and sit back from the bass and the treble making them perfect for electronic music.

Monstorous bass that is big and beautiful yet retains composure to convey big quantity sub bass and fast speed.

Blue Filters - In Open Back Mode (Summary)

So then we have the blue filters. Stepping from the coppers to the blue filters is such a marked difference that you have to wonder how they pulled it off. As mentioned I have had a few multi-filter IEM's, the best of which being the FLC model we reviewed last year. All of them had a similar sound when switching filters and the most marked changes came from the amount of low-end grunt.

The blue filters completely shift the weight of the signature. The energy and musicality remain but the top end becomes far more prominent, sparkly and forward. Mids also take a step forward especially strings and vocals. There is lots of detail in the midrange and imaging is just insane.

Lykie Lie on her track Time in a Bottle or the Magicians Remix on her track Follow bring to light the excellent mix of highs and lows. Yes, the low end is still very prominent but it tightens up its attack, has more focus on the mid and upper bass frequencies. As a sibilance test, we ran Caranvan from the whiplash soundtrack and both the trumpet solo and snares on the peak really impressed.

Soundstage & Imaging

Just a quick overview of the soundstage. With all of the filters, the soundstage is huge, one of if not the best I have heard in an in-ear headphone. It's full and expansive and displays a touch more with than depth. Really it's worth getting them just to try out the blue filters with the vents set fully open and throw on your favorite concert tracks.

Imaging is, of course, once again very very good. You will have no problem finding separation and placement of individual notes and tones.

Sound Summary

Its hard to believe I am actually being so positive about a headphone right? The thing is that these things sound so good they thoroughly deserve there place in the top tier of in-ear headphones. Not in the sense of "hey these are giant killers, they sound as good as earphones twice the price". No these stand on their own right at the top end of the market and the fact that they cost half the price is just a bonus. I evaluated them as a top tier earphone not as looking for something that represents a cheap way to top tier sony. You may lack some refinement in the style and design of the earphones against some of the other big names in the audiophile market but they do not give an inch in sonic performance.

If you like an energetic musical sound, lots of details, listen to a wide variety of genres and want big soundstage then these are probably right up your alley.

Standout tracks from our testing

Lykie Li - Unchained Melody

Two Feet - Quick Musical Doodles

Infected Mushroom - Spitfire

Roberto Caciapaglia - Atlantico

Carolina Chocolate Drops - Leaving Eden

Conclusion - An outstanding debut earphone