This and That:
Simple package design. Included accessories are three pairs of silicone tips and a soft velvet pouch. A case would have been better for protection.
Triple-BA, two acoustic ways (2x woofers, 1x tweeter), double-bore design. Visible acoustic dampers, tubing and crossover.
Ergonomically shaped plastic shells. Appear sturdy but aren't the thickest (neither are they the thinnest).
Cable that lacks some suppleness, strain relief and a chin-slider.
Sound:
I'm only using my Pai Audio MR3 with sources that have a very low output impedance.
I'm only using the largest included silicone tips.
Tonality:
The MR3 takes on a mildly v-shaped approach to neutrality.
The lows are evenly mildly emphasised by 5 dB compared to an in-ear with a diffuse-field flat bass response (Etymotic ER-4S/ER4SR), and carry ca. 2 dB more quantity compared to the Ultimate Ears Reference monitors. Therefore it has got similar bass quantity as the InEar StageDiver SD-2 (and likely also Westone W20 and Audio Technica ATH-IM02 that are said to be tuned like the SD-2).
Extension is flat down to 30 Hz with only a minimal measurable but inaudible level drop below that towards 20 Hz.
As the lows start climbing around 600 Hz and reach their climax around 100 Hz (but are already almost identically present at 20 Hz), there is also a bit of gentle fullness in the low fundamental range.
Voices and the midrange sound tonally mostly correct, natural and uncoloured. The mids aren't intimate though but just slightly in the background in the mix due to slightly reduced presence range quantity at 2 kHz (above, level is neutral). That's pleasant for long fatigue-free listening sessions without exhausting mids.
The highs are generally somewhat on the brighter side. The level is above neutral around 6 kHz and 9 kHz. Not narrow and fortunately not sharp/unpleasant, but definitely on the somewhat brighter side. Due to these two moderate and not narrow lifts, cymbals aren't fully natural sounding but appear a bit artificial/metallic, which is the in-ear's only flaw.
Resolution:
The resolution is higher than what one would probably expect for the price. For example, the MR3 clearly outperforms my Shure SE425 and is more or less in the same performance range as my Fischer Amps FA-3E (I'd say even slightly higher), just short of my Ultimate Ears UE900, UERM and Westone W4R.
The bass is tight, fast and highly controlled, as one would expect from the two small BA woofers. Bass details are high.
Speech intelligibility and midrange details are very high.
Treble details are clean and well-articulated. Note separation is very good.
Fast and busy, complex tracks don't strain the MR3 but it stays clean, coherent and doesn't become blurry/foggy sounding and can keep up the clean and precise note separation.
Soundstage:
One of the MR3's core strengths is its highly authentic soundstage. While most multi-BA in-ears in the < $500 price range don't have a three-dimensional, authentic soundstage but sound wide with no or only little depth, the MR3 does.
The expansion to the sides reaches a little wider than my shoulders, which is wider than my Logitech UE 900's soundstage, but in contrast to the UE, the MR3 features spatial depth that is almost as present as the width, resulting in a large, three-dimensional soundstage with pleasant, distinct spatial depth and precise layering.
Instrument separation, placement, layering and the portrayal of emptiness match the good three-dimensional impression and are precise.
Indeed, the MR3's soundstage is superb and very authentic; only few multi-BA in-ears in the three-digit price range manage to achieve comparable results in terms of spatial realism.
Take the UE900’s width, stretch it a little to the sides, add the Shure SE425’s spatial depth and voilà, you’ve got the MR3’s excellent soundstage. Brilliant!
Instrument placement and separation are on a very high level and even exceed the Shure SE425’s; overall soundstage is very harmonic, plastic and is almost as good as the Etymotic ER-4S’, which has got the slightly better instrument separation.
Conclusion:
Below-average cable, simple accessories. Balanced, v-shaped take on neutral. Upper treble sometimes a bit metallic and elevated but not sharp/unpleasant. Really good technical performance for the price. Truly superb soundstage.
Very high price-performance ratio with great sonic performance at the cost of the cable and accessories.
As a result, the MR3 is among the in-ears that have the honour of serving me for neutral stationary music listening (others are my Shure SE425, Fischer Amps FA-3E, InEar StageDiver SD-2, Ultimate Ears Reference Monitors, InEar ProPhile 8, Etymotic ER-4S, the Etymotic ER4SR and Noble Audio Savanna).