Moondrop SSR English Review


Fuzzy Heart




Construction and Design




  • Design and construction.
  • Tuning of the treble.
  • Very detailed and clean sound.
  • Cable.
  • Very reduced size.




  • Highly polarised midrange: there is a great distance between the lower and upper mids.
  • The details are more important than the fundamental part.
  • They require a certain power to move.
  • The low zone is not capable of handling very heavy, uncontrolled or unfiltered bass. At high volume, there is a risk of clear distortion.
  • Storage bag too small for use.


Purchase Link


Link to the Store




Moondrop is a relatively recent brand, as they were launched in 2015. Formed by several amateur engineers, they initially focused on bringing audiophile earbuds to market. After their first steps, with the VX and Liebesleid models, they became a company known for developing high-performance earbuds. After these, came the IX, the Kanas series, Blessing, A8… until now, with the SSR. It is worth noting that in these 5 years, Moondrop has become a brand known to all fans of this world, something that demonstrates its growth as a reference company. Its philosophy is based on investing to explore new possibilities for reproducing high quality sound, through the application of new technologies.

On this occasion, I have the pleasure of analysing the new SSR, a fairly economical model, which has brought about a small revolution in the market. After an intense advertising campaign, including a contest to specify the meaning of its acronym SSR (it won the Super Spaceship Reference), SSR came out on the market. These are tiny IEMS with a heart-shaped, all-metal shape. Its diaphragm has a beryllium dome together with a suspension ring, made of PU. Its magnetic circuit consists of a high density N52 magnet. But what is most surprising, is its curious frequency response, which has a first half (up to 1kHz) quite smooth and then a gradual rise that shows a clear emphasis, from high mids to high highs. Perhaps it is typical of many other IEMS, but the truth is that I consider myself a bass lover and few of my IEMS have a similar curve. Let’s see what these iron hearts look like.





  • Drivers type: Dynamic with Beryllium-Coated Dome diaphragm + PU Suspension Ring
  • Magnetic circuit: N52-High Density Magnetic Circuit.
  • Frequency Response: 20-20000Hz
  • Sensitivity:115dB/Vrms @1kHz
  • Impedance:16Ω @1kHz
  • THD: < 1%
  • Material of the capsule: Liquid Metal Alloy Housing
  • Coil: ⱷ 0.035mm – CCAW [Daikoku]
  • Acoustic filter: Patented Anti-blocking Filter.
  • Connector Jack: 3.5mm in angle
  • Cable: Silver Plated 4N-Litz OFC
  • Capsule Connection Type: 0.78-2pin





The SSRs come in a white, virtually square box. Its dimensions are 116x115x42mm. On its main side there is a drawing of a Manga girl, as a classic image of Mondrop, something that has been repeated in other models, even in other brands. On the back side, there is a diagram with the breakdown of the interior of the capsule, the specifications, in Chinese and English, as well as the frequency response. I want to emphasize that, by presenting such a graph, Moondrop is not fooling anyone. If you know how to interpret a graph, you can tell where the SSR profile will go, which is a daring thing to do, just by displaying it on the box.

Once the box is uncovered, you can see the SSRs, with their cable connected, embedded in a very black foam mould. At the bottom, there is a small elongated box, made of black cardboard, with the brand logo in silver letters. Inside it there is a small black bag, with the logo in white, in the lower right corner and a bag with the silicone tips. In short, the complete content is:


  • The two SSR capsules.
  • The 4N-Litz cable with 3.5mm angled gold-plated connector. The 2 pin 0.78mm connectors
  • Transport bag.
  • Instructions and warranty card.
  • 3 pairs of dark grey silicone tips, size SxMxL.


The box is very compact and tastefully decorated, with the inside of the capsule and the FR standing out. The transport bag is too small and is not suitable for storing the SSR, because the task is not easy, nor fast. The set of tips is the minimum necessary.



Construction and Design


I must emphasize that the design of the SSR capsules, I find most original. They are really small and you can choose between 4 colours: metallic grey, white, green and pink. In my case, I chose the white ones. The capsule is made of a liquid metal alloy. Its external face is asymmetrical, one half looks like a classic drawing of a heart and the other, an inverted little house, drawn by a child. At the lower vertex, a completely gold-plated allen screw stands out, its tip protruding from the inner side. There is a large hole next to it. The letters R and L, which identify the channel, are deeply inscribed in the metal. The nozzle is mounted on a large cylindrical base, approximately 5 mm long and 5.5 mm in diameter. Its interior is protected by a dense metal grid. At the foot of the metal cylinder, near the tip of the screw, there is a slot with a hole in the part closest to the nozzles. The 2Pin connection plate is embedded in the base of the «house». It is made of transparent plastic and the two hollow connection cylinders are gold-plated.

The Litz cable is 4-core silver-plated. It is covered with transparent plastic. The Jack connector is 3.5mm, angled and gold-plated. Its sheath is also transparent plastic, in a classic style. The dividing piece is a black plastic disc; on one side is inscribed the brand logo and on the other side its name. There is no adjustment ring. Near the two-pin connectors, there is a semi-rigid coating, to facilitate the adjustment on the ear. The two-pin connector is rectangular, slightly more bulky at the top and the two pins are completely external. A red ring, located next to the connector, serves as a channel indicator.

The capsules are actually very small and are painted bright white. Their design is special, and does not go unnoticed. But their small size, can damage the reproduction of the very powerful bass, perhaps there is not enough space for the complete elongation of the diaphragm.



Adjustment and Ergonomics


Such a small capsule, despite the design of the nozzle column, can only offer a superficial fit. Its small size allows rotation inside the hall. This makes the choice of tips essential for a long-lasting fit. In my case, I have to resort to larger or foam tips, to ensure their position and a good fit. On the other hand, for small ears, the size may be very adequate; for me, it has been a little more problematic. However, these problems have not been related to ergonomics, but rather to the sealing and, above all, the sound obtained. I have had to search through many tips until I found the best relationship between the lace and the best sound, something that is usually not very complicated for me.







The profile of the SSR is not quite normal, it has a clear enhancement in the upper part of the mids, with some treble present, without being offensive, and a light lower area centred on the mid-bass.Summing up, we could say that the profile is mid-centric and brilliant, and I’m very happy to describe it as such…

On the other hand, I would like to comment that the SSR are not entirely easy to move. Its small driver requires some power, while it is delicate when the volume is excessive. This makes their working range seem limited, in this respect, compared to larger IEMS.





Personally, I believe that SSRs are not suitable for Bass-Lovers. This is not their profile. SSRs are not even designed to withstand very heavy bass playback. Many songs on my test list contain hard, distorted or unfiltered bass. The small driver of the SSR, from a certain volume, is not able to handle them properly, reaching the audible distortion. But I must emphasize that this happens at a high volume, it is a warning to those who like to listen to music at high volume or for those who try to equalize the bass a lot, to give them more prominence

Returning to the general and calm description of the lower zone, the SSRs have a light emphasis, focused on the mid-bass, without their whole being very noticeable. The lows are light, clearly lagging behind the high mids, technically adequate, with good speed, realistic and contained hitting, clean decay and medium speed. The sub-bass is perceptible, never omitted, with good capacity of expression, but it has a sensitive fall at its lower end. With the right volume, isolating the area from the rest and good recordings, SSRs are able to deal with complex bases, providing an adequate sonority, with good speed, but without being able to fill the scene with all the nuances, details and bass planes, in relation to the rest of the audible spectrum.

The texture of the bass is soft, with medium roughness. But it is still capable of providing a light sediment or noticeable effect, which makes it very pleasant clearly, on a qualitative, technical and sound level. In short, the SSR has a bass that is very suitable and capable for those who are not particularly interested in a superior presence of the lower zone. They fulfil their role, adjusting their quality to their profile.





SSRs have a clear emphasis in the upper mid-range, which is quite common these days. What is not so common, is that its lower zone has a negative, so clear, face-to-face distance. In this sense, the sound of the SSR is polarised. Its lower part could be qualified as underexposed, at medium distance, while its details, sparkles and harmonics, are splashed and more present. This presents a sound where small aspects become more important, than male voices, for example. The timbre is not incorrect, but the melodies belonging to the lower range, come to feel somewhat omitted, while their sparkles and harmonics surpass them in presence. This causes a different pattern, which is difficult to get used to; more so, if you come from typical V profiles or warmer ones, where the bass and  lower midrange has a higher prominence, as opposed to the upper half.Despite all this, the SSRs do not feel completely bright, but have a slight warmth that distances them from an explicitly clear or analytical sound.  But I really think that in this way, more importance is given to the accompaniment elements, than to the instruments that really carry the weight of the melody. As I say, the details are more exposed than male voices or a bass line. Thus, the cymbals and those details with a sharper fundamental sound above the main line of a song. But this doesn’t mean that the rest sounds bad. But some may try to raise the volume, to bring the main body closer, which is actually a bad choice, because the details will still dominate over the lower mids. Thus, the first half of the middle range lacks a wide and vigorous body, the scene does not feel flooded and the sound does not have the right pulp and roundness. The male voices are drawn fine, with good timbre, smooth and with a very soft texture, which does not enjoy many details, nor nuances. The same happens with the main instruments of the area. On the other hand, the upper half of the voices are very cold and bright, and will become splashed and vivid, perhaps more than usual. All those details and classic nuances of this upper half will fly around in your head in a clear and perhaps even too persistent way, but without losing the realistic tone, it is just a matter of more energy, not an analytical, cold or eminently sharp timbre. By way of example, female voices do sound fuller, but even, from the beginning to the end, including breathing, sighing and hissing. In short, a lot of cymbal and little bass drumming, for a middle zone that could be very good, if the tuning had been flatter, in that happy upper half.





Luckily, the high notes have an energy more in keeping with the exposure to detail, but without being overpowering. On this occasion, I feel that the upper zone has a more correct tuning, stopping at the right point and suitable for not losing that slight warmth, which the SSR enjoy. The treble has a good relationship between its amount of energy and its width: it doesn’t look completely fine or sharp, nor does it rise beyond the upper midrange, which makes it a good match and a better accompaniment, for the rest of the range. Even, its extension is very well achieved, providing a very good feeling of clarity, separation and an adequate dose of air. In this way, the high notes are not excessive, nor sharp, nor only brilliant or exasperating. On the contrary, they can be enjoyed without restriction, thanks to their good measure, exposure and correct execution.



Soundstage, Separation


Both the scene and the separation are positive points in SSR. Without reaching excellence, the recreated scene appears quite round, with a good relationship between the three coordinates, although the width predominates. The perception of the sound is semicircular, eminently frontal, although slightly surrounding, thanks to the notable exhibition of the details, its correct location, origin and drawing. The cleanliness of the sound is quite high, which generates a good feeling of space and separation. The background is not completely dark, since it is possible to perceive how the notes come together in the deepest part, perhaps as a result of the omnipresence of the high mids and their echoes. It is likely that this fact is also to blame for the fact that details and nuances are over exposed and that micro details are perceived as more omitted, covered up by the greater presence and prominence of those details.





Faaeal Hibiscus


Duel between Hibiscus girl vs Moondrop girl. Both models share a drawing of a manga girl on the cover. Currently, the price of the models is almost the same. In terms of accessories, I prefer Hibiscus: although the SSR cable is good, Hibiscus have the best cable in the range and I could say that, below $100, there is no model that brings a better cable than this one (this is a personal opinion, among all the models I own).

Hibiscus are made of plastic with a large, thick semi-custom capsule. Its ergonomics are not bad at all, but its thickness may be excessive. SSRs are much smaller and metal. In my ears, they barely touch, while the body of the Hibiscus, is more noticeable, without bothering me. Amongst other things, the ergonomics, although different, provide a similar degree of comfort and a superficial fit.

As for the sound, the curve, roughly speaking, points to similarities that are then not so obvious. Hibiscus have a very linear low zone, but descending towards the sub-bass, which limits the presence of the low zone and the body of the mid-low. The SSRs, comparatively speaking, offer more bass, and are even technically superior. The lower zone of the Hibiscus is so light and harmless, that it is difficult for them to do badly, even though their speed is not very fast. In this sense, the lower zone of the SSR, with its more noticeable mid-bass, adds a very flattering warmth to their sound. Hence, the lower middle zone is perceived as more complete and closer, where the Hibiscus shows an excessive hollowness, neutrality and lightness, which provides an incomplete sonority in the male voices and instruments of this zone. They feel colder and pushed upwards, thinner and less natural. Despite all that has been said about SSRs, they generate a tonal sound that is more appropriate and natural, with a more realistic timbre and without that incomplete feeling. On the other hand, the high mids in Hibiscus have more control and balance, and sound more natural and less aggressive. At the top, the highs feel more limited and softened. The SSR, on the other hand, has a more complete, complex, present, explicit and full upper zone, with a more accurate tuning, as well as greater extension. The detail is more marked in them, while the micro detail is better perceived in the Hibiscus. In these, there is a greater sensation of air, a more ethereal and aural scene, thanks to the more distant sound it offers, being perceived with greater three-dimensionality and more volatile. The greater dispersion of the sound, increases its sense of separation and its background is perceived as more empty. SSRs sound denser and more complete, with a more marked, exposed and longer detail, which covers the micro nuances and brings the background together. The scene, although quite good, is smaller, appearing flatter and closer.

Finally, it should be noted that the Hibiscus can withstand much better, the positive equalisation, especially in its lower zone.






Ever since the SSRs came out I have been curious to try them out. First, because of their size and outstanding design. Second, because of their frequency response, although this did not fit within my preferences. In this sense, I want to emphasize that this graphic is real. In this way, any fan can have an idea of what he is going to find, in general terms. And it really doesn’t deceive anything. SSR have a neutral low zone, over exposed mid-high and adequate treble. They have a certain warmth and a preference for presenting more details than the main thing. However, tonal and timbral, they are not out of the way, although both have a brighter character. On the other hand, the first half of the spectrum feels somewhat orphaned and distant, which makes the sound suffer in the representation of the musical body, losing in pulp and juiciness. However, the scene and the separation continue under the premise of realism, generating a clean, present sound, with good separation and quantity of air, which flees from the congestion and the narrowness.

Personally, I think that the tuning is not the most adequate to my personal taste, if the low zone would have more emphasis, above all in the sub-bass (without overdoing it) and the presence of the high mids would be limited in the same proportion, perhaps a very convenient balance could be reached, which could satisfy many, or at least me.



Sources Used During the Analysis


  • Burson Audio Playmate
  • Qudelix-5K
  • xDuoo XP-2Pro
  • HyBy R3 Pro
  • Tempotec Serenade iDSD