Custom In-Ear Monitors (CIEM) Review Previews

Short previews of upcoming CIEM reviews.

Preview information available:
Mi-Performer Pro custom in-ear monitors
Perfect Seal Fusion 11 custom in-ear monitor
EarSonics EM32 custom in-ear monitor
EarSonics Velvet universal in-ear monitor

Please remember that these are previews and my overall evaluation may change based on more testing.  If you have any questions, please ask them in the comments section below.

See the custom in-ear monitors review list for products with full reviews.


Minerva Mi-Performer & Mi-Performer Pro custom in-ear monitors Mi-Performer Pro: Minerva has been making hearing related products for over half a century and got into the CIEM game several years ago with the Mi-3.  They recently updated their lineup, replacing previous CIEM products with the Mi-Artist Pro and Mi-Performer Pro.  The Artist Pro is a dual driver in an acrylic shell with detachable cable while the Performer Pro is uses the same dual balanced armature driver housed in silicone.  The cables are different, but both nice.

As far as fit goes, the Mi-Artist Pro acrylic shell is the tightest fitting acrylic shell I have that doesn’t cause pain or discomfort, except when removing.  This CIEM does best with a push-in insertion method vs. a twist-in, and especially during the removal.  The Performer Pro also fits snugly, but isn’t quite as tight.

Sonically, they are quite different than the Mi-3, with a more forward overall presentation and a good deal more bass capability.  The Artist Pro and Performer Pro share a mid-forward presentation, but the Mi-Performer Pro outperforms the Mi-Artist Pro in bass extension and capability while the Mi-Artist Pro has better dynamics, treble extension, and treble quality.  The Performer Pro midrange is more forward and also resolves more detail than the acrylic shelled Artist Pro.


Perfect Seal Fusion 11 silicone hybrid custom in-ear monitorThe Perfect Seal Fusion 11 is the first silicone shelled hybrid CIEM, and that is pretty cool by itself.  But, when listening there were several things that jumped out at me and made me grab some of the top-tier CIEMs for comparison.  The first is tonal balance, which is spot on, and a close second is the coherence between drivers, which is significantly better than the other dynamic + ED hybrid I have, the Thousand Sound TS842.

The bass quantity can be adjusted by changing out plugs, and there are 5 different settings to choose from (for now).  While the solid plug has quite a neutral sound to it, the deep bass is a bit rolled-off, and the next plug up in bass quantity, the yellow filtered plug, has bass that is north of neutral.  The red filter, small hole ports, and completely open all add bass quantity, with the amount increasing in that order.  I found myself listening primarily to the yellow filter but would prefer the solid plug if the deep bass had more weight.

The midrange and treble are very neutral and reminiscent of the much more expensive Lear LCM BD4.2 in linearity, but not as detailed and with a very different presentation perspective.  While the Lear presents from a distance with a large space, the Fusion 11 presents much more forward perspective similar to a stage monitor sound.  Switching back and forth did not leave me wanting from either.  The presentation perspective is reminiscent of EarSonics products, and the EM4 is quite close.

Comparing the Fusion 11 with the Heir Audio 8.A, the tone sounds more balanced with less bass emphasis (yellow filtered plug) and more treble emphasis leading to better clarity and a more natural tonality.  Even though the Fusion 11 is a hybrid, it has better coherence and transparency, and the soundstage recreation is more linear.  Compared with the Lime Ears LE3B, the Fusion 11 offers better clarity, transparency, and coherence for a better listening experience.

The Fusion 11  performs closer to the EarSonics EM4 from a technical standpoint, but the tonality is different as the Fusion 11 is brighter and not quite as smooth.   Comparing with a new flagship such as the Hidition Viento-R, the Fusion 11 doesn’t quite perform at the same level, but the fact that I can switch between the two and not be disappointed with the Fusion 11 says something.  Given a base price around $500, the Perfect Seal Fusion 11 offers stellar value for money.


EarSonics EM32 Custom In-Ear Monitors

The EarSonics EM32 has been out for a while now, but I managed to get my hands on one and was surprised by the different direction taken with the sound signature.  The EM32 has a bass emphasis combined with quite good capability resulting in the ability to convey quite a bit of power and emotion, edging out the EM4 and leaving the S-EM6 far behind in this regard.  The presentation perspective is more laid-back than typical for EarSonics, approximating the neutral performance of a “reference” CIEM, which is different than the more forward EM4 and mid-centric S-EM6.  Spatially, the presentation space of the EM32 is slightly larger than the EM4, which is larger than the S-EM6.  Imaging is close, but not quite to the level of the EM4 but close to the S-EM6.

EarSonics, while not considered dark by many, wouldn’t be mistaken for a bright CIEM.  Well, the EM32 is the brightest EarSonics product I have heard to date, and the treble is reminiscent of the Ultimate Ears In-Ear Reference Monitor in that it reveals poor quality quite well, but does fine with better quality tracks.  In my initial listeing testing, I did notice the transparency to source and track as performance changed a good deal track-to-track.  With all that said, the sound signature still has EarSonics overtones and isn’t a total departure, but more of a different flavor.


EarSonics Velvet in-ear monitorsThere have been a lot of questions about the EarSonics Velvet universal in-ear monitor and how it compares with other universal fit EarSonics products, so I have done comparisons to the SM64 and S-EM6, which are below.

Vs. SM64:

Sharing the EarSonics sound signature, the SM64 has a more laid-back presentation but a smaller average soundstage and less capability to project sound in the distance.  Imaging, layering, and presentation depth are better from the Velvet, which offers a more clear and concise presentation.  Average note ADSR is similar, but the Velvet has a more natural decay resulting in a smoother, more natural sound.  Detail levels are significantly higher with the Velvet and resolution within the soundstage is also better.  Transparency and coherence are also better from the Velvet.

Bass of the Velvet is more prominent, especially deep bass, even at a quarter turn of the bass knob, conveying much more power.  Warmth is similar as is thickness.  The Velvet has a good deal more clarity within the midrange with a cleaner sound that conveys more detail and adds layers the SM64 doesn’t have resulting in a more involving experience.  The upper midrange of the SM64 is more laid-back, as is the treble, and the quality of the Velvet in both areas is superior.

Vs. S-EM6:

The Velvet and S-EM6 share EarSonics house sound characteristics, but have different presentation perspectives and average note speed.  The bass adjustment knob of the Velvet can turn the bass up significantly higher than what the S-EM6 naturally produces, with about a quarter turn from minimum for an equivalent level.  Spatially, the Velvet has a slightly more laid-back presentation perspective and a more open sound but a slightly smaller overall space while the S-EM6 has better imaging for a more realistic and resolving soundstage.  Notes of the S-EM6 are a bit more analytical yet thicker, with a sharper attack and decay yet longer sustain leading to a good deal more detail and punch despite the thicker sound.  Coherence and transparency are similar while clarity is slightly superior with the Velvet.

Deep bass of the Velvet is more pronounced than the S-EM6 at all but the absolute lowest knob settings, which results in similar amounts.  When the sub-bass is adjusted to similar levels, the S-EM6 is warmer.  Bass quality is close, but the S-EM6 is a bit tighter with better laying.  While the S-EM6’s more forward presentation has better layering and presentation depth, the slightly more laid-back Velvet has a cleaner sound that is more open.  The upper midrange of the Velvet is slightly more prominent in relation to the midrange than the S-EM6, as is the treble.  Treble notes are smoother on the Velvet, but more revealing of issues with poor quality tracks.

The universal shell of the Velvet has a longer distance from the housing to the end of the nozzle resulting in a better fit.  Sensitivity is similar, but the soundstage presentation and note characterizes allow the Velvet to retain its clarity at louder volumes.


by average_joe


  1. Wow, looks like earsonics have a winner with the velvet.

    I smell an epic full review incoming 😛

  2. So, I take it that the Perfect Seal Fusion 11 is better than your current $500-$750 pick, the aud-5X?

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