Rank #11: EarSonics S-EM9


The S-EM9’s bass is not your typical snappy BA bass; in fact, it seems to have the vague resemblance of a dynamic driver. Its bottom-end extension reaches deep, providing a nice bit of rumble down low. And it has a well-timed decay that gives it an un-BA like naturalness in its decay. But most of all, its moderately enhanced quantity packs a solid punch with bass-heavy music. It’s an engaging bass that isn’t too intrusive, but nevertheless fits the bill as ‘musical’. It’s one of the reasons the S-EM9 has been a long time favorite for electronic or pop music, along with its overall precision. Quite frankly, it’s evolved as one of my favorite BA-driven bass, although it wouldn’t nearly classify as bass-head level in terms of quantity.

Even so, the added body in the mid-bass might add impact, it also slows down its pace. The more technically-oriented bass of the likes of the NTpro is quicker for example. The result is a warm bass, relatively natural in tone, with the right speed of decay to provide a natural finish. The enhanced bass and its somewhat lingering decay provides a warmer touch to the stage, as well as the midrange. In addition, its definition is about average. Taken together, it might not be the most technical bass in terms of speed or resolution; but it’s a much appreciated bass for its low-end extension and engaging impact.

The S-EM9’s midrange wasn’t the focus of its tuning; it might have even been sacrificed a bit for the greater good. It’s somewhat laid-back, so it isn’t necessary very full or forward-sounding. In addition, the S-EM9 isn’t necessarily particularly upfront with its detail presentation – compared to brighter tunings, some might even find it a bit dark. But make no mistake, the S-EM9 is highly detailed; it just relies on its top-end extension, rather than the sensitive upper mid region. Besides, the S-EM9’s midrange has other essential qualities. It’s slightly warm in tone, and remarkably quick – the S-EM9 easily keeps up with faster music, keeping some of its slower peers behind. And due to its upper midrange dip, it’s remarkably smooth. It might have a slight treble lift, the midrange itself isn’t bright or harsh by any means. It’s an airy, quick, though somewhat delicate, midrange.

The S-EM9’s vocal presentation is centered on the stage, both in terms of width and depth. It’s flanked by instruments in the front and rear – the S-EM9’s layering ability is quite good. Still, in relative terms vocals can be considered laidback. But not all is lost; there’s a bump around 1 KHz – the foundation of the S-EM9’s midrange. It provides some body to the sound, giving vocals just the right amount of density, even though they aren’t very thick. The vocal presentation is affected by the lower and upper midrange dips, which attenuate the full vocal range at each end; both the chesty, powerful feel at the bottom, and the pronunciation towards the top. What remains is nevertheless a crucial area for a solidified, rounded vocal; it’s just not its strong suit, at least compared to its competition. And while it isn’t the most powerful, it has other essential qualities; its tone is warm, and the articulation is smooth.

The upper midrange dip is a recurring theme. It’s a crucial area for determining many instruments’ size. The S-EM9’s dip makes instruments leaner, shorting the size of guitars and violins, while giving them a more laidback position on the stage. It’s effective for its separation, but it isn’t particularly forward. And at least equally important, it affects the accuracy of their timbre. Attenuating this region makes the midrange a good deal smoother, but it also takes some light from its tone; the resonance of a chord doesn’t quite shine as it could, and needs to rely on the lower treble for a touch of sparkle.

Like so many of its peers, the S-EM9 has a 7 KHz peak that boosts its overall clarity. Notes are articulated, and its imaging is precise. It’s an airy treble, creating sufficient space around instruments. And while the treble is slightly pronounced, it stays relatively close to neutral in overall quantity. It doesn’t have that warmer touch for it to sound completely accurate in tone, but it isn’t bright either. It’s a treble that adds some life and sparkle to melodies – especially those synthetic in nature.

But the qualities of this treble lie in its speed and precision. It’s articulate, detailed, and well-defined: a refined treble presentation, not in the last place because of its excellent and very linear top-end extension, ranging up to 15 KHz. Moreover, its decay is quick. This is a treble that feels like it speeds up the rhythm, even in slower tracks. And because it remains smooth, it’s a treble that invites you to turn up the volume, rather than turning it down – a smooth, but engaging treble.

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About Author

Nic is currently in pursuit of a PhD degree in social neuropsychology, while trying not to get too distracted by this hobby. In pursuit of theoretical knowledge by day, and audiophile excellence at night. Luckily for him, both activities are not mutually exclusive which helps to lighten the workload. Always on the go, Nic's enthusiasm for hi-fi is focused on all chains of the portable system: iems, cables and daps.


  1. I have a chance to pick up sem9 for 40% off. Could you let me know whether they are suitable and is there anything better in around £800 for folk, classic rock and pre 2000 pop music. Thank you.

    • Hi there, it’s a bit hard to predict since it depends on preference. Personally I enjoy the S-EM9 especially for pop music. It will also work for folk and rock, but the vocal presentation is not particularly forward and present, it is more a linear balanced presentation where the instruments are in line with the vocals. So if you are looking for a deeply powerful, emotional vocal experience they might not be ideal. But in general I would consider it an allrounder.

      • Thank you for your replay flinkenick. I really enjoy the sound of S-EM9 however, as you pointed out vocals can sometimes be on a quieter side especially in older recordings. I am looking to upgrade the cable now and given your expertise I would really appreciate if you could recommend me some options around $300 that would enhance or better separate the mids without changing overall sound signature. At the moment I am using stock Westone cable that helps a little. Thank you.

    • Apologies for the late reply, it seems my notifications have been going to spam so I missed the past comments. I guess a good allround player would be the DX200, as it is versatile and neutral in tone. The LPG is also great if you can find one second hand, or maybe an AK player at a good deal. But it really depends on preference, some might prefer a warmer or brighter sound so it would be good to figure that out for yourself first.

    • The Velvet and S-EM9 both share an enhanced bass and lower treble. But the Velvet’s bass is focused mostly on sub-bass, where the S-EM9’s is more balanced between sub- and mid-bass. As a result, the Velvet’s bass is punchy and impactful, but its mid-bass is not very natural in tone compared to the S-EM9. The S-EM9 has a bump around 1 Khz which brings its midrange a bit more forward and gives it more focus. By comparison the Velvet’s midrange is thinner and laidback, especially since its lower treble around 7 Khz is more articulated, while it sounds brighter due to a more elevated 12 Khz peak The S-EM9 has great extension, but the upper treble is less prominent. Accordingly, it sounds smoother and closer to neutral, where the Velvet is brighter and more energetic.

  2. Some advice for people wanting to get the Sem-9. Upgrade your cable immediately. A simple SPC cable like the Thor SPC will do wonders for the soundstage and clarity of the IEM.

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