Sound analysis.

Even so I was itching to switch the cable, for sound analysis I went back to a stock OFC wires because that’s how others will hear the sound out of the box.  Also, I put S-EM9 through about 100hrs of burn in, though I haven’t noticed any changes in sound.  After extended listening using my trusted reference quality PAW Gold and Opus#2 sources, here is what I found.

I hear SEM9 as having a very natural revealing tonality with a balanced signature that has a slight lift in sub-bass and upper mids area.  Actually, SEM9 signature can slightly fluctuate depending on the selection of eartips and the cable.  With my eartip mod allowing me to use a large size long stem tips – I was getting an earplug like isolation with an amazing bass impact.  Going with a smaller eartip, one size down, relaxes the intensity of the bass and I get a little more airiness in the upper frequencies.  Switching to pure silver or gold plated silver wires lifted a bit of a veil off the smoothness and sharpened the details of a balanced signature which pushed the sound more toward W-shaped performance (more emphasis in all 3 frequency ranges).  But regardless of these changes, the sound remained very clear and detailed, smooth, natural, and very coherent.

In more details, I hear a deep sub-bass extension with a velvety smooth textured sub-bass rumble.  The sub-bass is slightly elevated, giving more weight to mid-bass punch which has an average attack speed and decay, making it sound less like a BA driver and more like a performance signature of a dynamic driver.  It’s quite amazing considering that low end is covered by a single BA which sounds more like a dynamic driver, and still is well controlled without spilling into lower mids and quite articulate with smoother analog level of details.

Lower mids are not too thin or too thick, yet they have a nice smooth neutral body which in comparison to slightly lifted upper mids creates a nice separation from a bass.  Again, playing with different eartips and especially the cable (Thor II+ pure silver and TWau Reference), turned upper mids from smooth detailed into more resolving with an improved retrieval of details.  It doesn’t reach analytical performance level and still remains very natural, though the cable upgrade did lift the veil off upper frequencies and enhanced the clarity, especially in vocals.

Treble is well extended, with enough clarity and crunch, well controlled airiness, and a great definition of details.  With a stock cable the treble is smoother while with an upgrade the level of airiness goes up, which in turn improves the layering and separation of instruments, giving the sound more crisp definition.  I didn’t hear even a hint of sibilance, but you should be aware there is a peak around 7k (also confirmed by my measurements) which improves the clarity of the sound without harshness or graininess.

Regardless of the cable selection, soundstage is very wide but in a natural way without feeling artificial.  The depth of the sound is pushed a little outward, giving it a more holographic out of your head feeling, but not too much.  With such width/depth of soundstage and a decent level of transparency, you also get an excellent layering and separation of instruments and vocals.  Even with a stock cable which makes sound smoother, it never gets congested.  But switching to silver or gold-plated silver cable scales this performance to another level.  To be fair, I did all my sound analysis using a stock cable, but I’m definitely switching to an upgraded cable afterwards because stock cable doesn’t do a justice to a sound quality of SEM9.

Sound comparison.

Each pair of the following IEMs/CIEMs were tested and compared using their corresponding stock cable, and I matched the sound level by ear.  Opus#2 single ended output was used as my reference source.

SEM9 vs U12 w/B1 – 9 has a wider soundstage with a more hollow depth where I hear mids/vocals being more out of my head while 12 width is slightly narrower and the vocals are closer and more intimate. 12 upper mids/lower treble are a little smoother and more organic, while 9 upper mids/lower treble are more transparent and revealing, and treble has a little more sparkle. That also contributes to an edge in better layering and separation of instruments, but at the same time U12 upper mids sound just a little more organic.  The low end, from sub-bass extension to mid-bass punch, and the lower mids smooth full body are very similar. Interestingly enough, the shells have a similar shape and size, except U12 nozzle is longer.

SEM9 vs Andromeda – Andro has more hissing, the soundstage width here is very similar but I hear 9 having a little more depth with mids/vocals being a little more out there.  When it comes to low end, Andro has a little deeper sub-bass extension and a little more mid-bass punch, while 9 bass is a little more polite in comparison.  Lower mids are similar but upper mids in 9 are smoother, a little more relaxed and natural, not as intense and a little more forward.  Andro treble is crisper, has more sparkle and more airiness, while 9 is smoother and more relaxed.

SEM9 vs ES60 – Soundstage width is similar, maybe with 9 being a touch wider, but the depth is more holographic in 9. ES has a little more sub-bass and a noticeably stronger mid-bass punch.  9 lower mids are a little more neutral in comparison to ES which has slightly more body.  9 upper mids are a little brighter and slightly more revealing and transparent, while ES is a little smoother and more organic in comparison. Treble is very similar, though I hear ES having a touch more sparkle.

SEM9 vs K10UA – 9 has a wider soundstage, while the depth is very similar including that slight out of your head holographic expansion, though 9 pushes it a little further. With low end, K10UA has a little more sub-bass rumble and a little stronger mid-bass punch. Lower mids are very similar in tonality and the same with upper mids and vocals, though I hear 9 being a touch more forward and a little smoother and more organic.  K10UA treble is a little more crisp and has a touch more sparkle.

SEM9 vs Harmony 8.2 – 9 has a little wider soundstage, while the depth is very similar though 9 still has a little more out of your head holographic expansion.  Sub-bass is very similar while H8.2 has a stronger mid-bass punch.  Lower mids are similar as well, while upper mids in 9 are a little smoother and more organic in comparison.  Treble extension and tonality is very similar between these both.

Pair up.

The pair up test was done using S-EM9 with its stock ofc cable.  Considering 121 dB sensitivity and 38.5 ohm impedance, I was expecting to hear a strong hissing with many of my sources.  To my very pleasant surprise, S-EM9 has hissing down to a minimum!

theBit Opus#2 – smooth, revealing, slightly mid-forward signature with a little polite bass (north of neutral but not elevated), neutral lower mids (not too much body and not too thin), slightly pushed forward clear detailed mids, crisp, well defined treble.  Wide soundstage.

Lotoo PAW Gold – more revealing and balanced signature, mid-bass has a stronger punch, neutral lower mids, clear detailed upper mids which are not as pushed forward as Opus#2, a little more analytical upper mids, bright, crisp, detailed treble.  Wide soundstage.

Plenue M2 – revealing, slightly mid-forward signature, more rumble in sub-bass, neutral mids, revealing detailed upper mids, crisp extended treble.  Soundstage is wide, but mids have a slightly holographic depth, pushed more out of my head.

FiiO X7 w/AM2 – smooth, revealing, more balanced sound signature, with a nice sub-bass rumble and strong mid-bass punch – bass is tight and articulate.  Lower mids are neutral, while upper mids are revealing, detailed, with lots of clarity; treble is bright, crisp, detailed.  Wide soundstage with slightly distant upper mids/vocals pushed out of my head.

A&K AK120ii – smooth, detailed, balanced sound signature, with a tight articulate bass that has a nice fast punch, neutral lower mids, and clear detailed upper mids which sound very natural; treble is crisp and detailed.  Soundstage is wide, while depth is more natural and less holographic.

Cayin i5 – smooth, detailed, balanced sound signature, excellent bass with a deep sub-bass rumble and fast punchy mid-bass, slightly more body in lower mids, and bright detailed smooth upper mids, treble is bright and crisp, but a touch less airiness.  Soundstage is wide, and depth is more intimate (not too much out of your head).

Galaxy Note 4 – smooth, detailed, very balanced signature, bass is hard hitting with some impressive authority, but upper mids/lower treble are a little less revealing and smoother/warmer. Also, soundstage width is good but not as wide as with some DAPs.  Not bad for a smartphone pair up.

Conclusion.

The intent of my earphone reviews, especially when it comes to pricier flagship models, is to help my readers in their journey to narrow down available choices based on their sound preference.  Lately, this task has been not easy to carry out because there are so many great IEMs/CIEMs where you can’t just pick one as the top performer.  But S-EM9 managed to come close, even challenging some of my previous favorites.  Its natural revealing spacious sound works great with every genre of the music, regardless if it’s a vocal performance or instrumental rendition or a slamming EDM track, and you can listen for hours without fatigue.  Also it has a very comfortable and lightweight design where with a right set of eartips I have been using them even as earplugs at my work.  Don’t expect exaggerated bass slam or a revealing analytical performance.  Instead you will find a masterfully tuned signature that will hit a sweet spot and will appeal to many audiophiles and audio enthusiasts who want a happy medium without compromises.