Reecho SG-03 English Review


The Many Faces of Power




Construction and Design




  • Sub-bass quality and quantity.
  • Close mid-range for its profile.
  • Separation, amount of detail and micro nuances.
  • Great design and construction.
  • Good tuning for good timbre and tone.
  • Ergonomics.
  • Could be a reference in its class.




  • Somewhat heavy weight of the capsules.
  • Although the cable is OK, the sound could be improved with a better cable.
  • Few tips, only one set.


Purchase Link


Link to the Store




Reecho is a relatively new headphone brand. It surprised with the standard of its Spring and Summer models and then moved into a higher product in the price range, such as the Insects Awaken. For the new model, they’ve lowered the price bar, but without reducing the quality. This time, they have opted for a single dynamic driver, instead of the previous multidrivers: Spring (2BA+1DDD), Summer (2DD) and Insects Awaken (4BA). Another striking thing that has changed is the resin of their colourful bodies, for the metal and uniform colour of the SG-03s. The capsules are made of aircraft-grade aluminium alloy. Their ergonomic design is based on collaborations with world-renowned hearing aid companies to take advantage of large databases of human hearing measurements. In this way, these IEMS are able to adapt faithfully and effectively to our ears, also increasing the level of isolation. Internally, the SG-03s use a dynamic driver with NdFeB N50 magnets and a high-rigidity titanium-plated diaphragm. With a frequency range of 20Hz to 40kHz, these new SG-03s comply with the Hi-Res standard, proposed and defined by Sony and developed by the JAS (Japan Audio Association) and the CEA (Consumer Electronics Association).
In the following review we will take an in-depth look at all these details, as well as an analysis of their sound.





  • Driver Type: Dynamic 10mm N50 with titanium plated diaphragm.
  • Frequency Response: 20Hz to 40kHz
  • Sensitivity: 106 ± 2.5dB / 1mW @ 1kHz
  • Impedance: 16Ω
  • T.H.D: <2% (@ 1kHz/1mW)
  • Jack connector: 3.5mm SE gold plated
  • Cable length: 120cm ± 0.1m
  • Cable core material and weaving method: 4 strands of high purity oxygen free copper
  • Capsule Connection Type: 2 Pin 0.78





The Reecho SG-03 comes in a blue rectangular box, dimensions 157x124x51mm. In the centre, large SG letters stand out, in white ink. Below them, you can read «STAR GATE», in a much smaller font. At the bottom right is the Hi-Res Audio stamp and at the left, also at the bottom, a white oval with the model name inside. Underneath, the text «In-Ear Monitor». At the top left, «Reecho» appears in a white box with rounded corners. The rear face shows, at the top, an exploded view of the inside of a capsule. Underneath are all the specifications and descriptions of the product, in Chinese and English. Removing the cardboard box reveals an all-black rigid box. In the centre of its front face is the model name, in silver letters, in a medium-sized font, but much smaller than that of the outer box. Lifting the lid is a black cardboard envelope, in the centre of which, this time, is the brand name, also in silver letters. Underneath is a foam mould which holds a clear grey zipped pouch with white brand lettering, and at the top, the two capsules. In the envelope are various instruction and warranty cards. Inside the sleeve is the cable and a set of black silicone tips. The gold-plated 3.5mm SE connector is protected by a plastic sleeve. In summary, the complete contents are:


  • The two capsules.
  • The 4-strand high purity oxygen-free copper cable.
  • 3 pairs of black silicone tips.
  • A hard case for storage.
  • 3 warranty/instruction cards.


The packaging is of medium size. The case is also medium sized, of a shape, size and quality that is becoming common in other models. Personally, I like it a lot. The set of tips is the minimum necessary, I would have preferred a different set and some silicone tips.
Overall, both the presentation and the contents are discreet and acceptable, without much more to say.



Construction and Design


The construction of the IEMS is already very different. The capsules are made of aircraft-grade aluminium alloy and manufactured on a 5-axis CNC machine, which takes 120 minutes. The design of the outer face is based on 6 planes that cut into each other, resulting in 6 smooth faces whose edges give a trapezoid shape to their longest face. On this face, on the right capsule, there is a large, white letter G. On the left side, the letter S, also white. The capsules are bright blue, but somewhat dark. The inner face contrasts with the outer face, as instead of being flat, it is very rounded, with marked protuberances, peaks and valleys that give rise to a very ergonomic shape. It is worth noting that the body is thick, but this is not a simple design, as it is intended to fit our ears as closely as possible. To this end, the partnership with world-renowned hearing aid companies has been key to recreate a shape that is as particular as it is easily adjustable to the anatomy of our ears.
On the edge is the 2 Pin 0.78mm connection, at the same level as the surface. Close to it, there is a small hole, also on the edge. On the inner side, on the side, there is a large protrusion which is anchored in the upper part of the ear. On the way to the mouthpiece, there is another hole and, next to it, the letter indicating the canal, in white ink and inside a circle of the same colour. The base of the mouthpieces is not without a peculiar, ergonomic shape. Above it is a more classical structure of two concentric cylinders, the first one with a diameter of 4.5mm and the upper crown of 5.8mm. The overall length is 3.5mm and the opening is covered with a dense metal grille. The capsules have an outer face width of about 25mm, while the maximum thickness, from the outer face to the tip of the mouthpiece, does not exceed 23mm. However, the minimum thickness is more than 15mm, which corresponds to a relatively thick capsule.
The cable has a classic design, which reminds me of other models, for example the Tri-Fi. It is a cable with 4 black strands wound in a spiral. The connector is a 3.5mm connector, with a black angled plastic cover. The splitter piece is a small elongated rubber piece and has no adjustment pin. There are two over-ear guides, created from a semi-rigid coating, and the two-pin connectors are protected by small, classic black plastic sleeves. A coloured dot on the edge of the sleeves (red and blue) indicates the channel and position.
The capsules have an excellent construction, very robust and seamless, with a clear and distinctive shape, unmistakably particular. The cable, despite being a simpler, high-purity, oxygen-free copper cable, is highly manageable and tangle-free, nor is it microphonic. It lacks a tuning pin and the possibility to choose a balanced plug. Otherwise, spectacular design, superior construction and fairly decent cable.



Adjustment and Ergonomics


In these respects, Reecho’s aforementioned partnership with world-renowned hearing aid companies must bear its best fruits. In my particular case, I must confess that the fit is almost excellent. The anchorage is very good and the IEMS do not move, there is no rotation, no danger of falling. Although there is contact with some parts of the ear, they are not uncomfortable, nor do you feel the weight more than necessary. I have tried them for several hours and only at the end did I notice a slight discomfort. But this is normal, due to the minimal contact.
It is true that I miss the possibility of a deeper insertion. In my case, the insertion is shallow, as the protrusions that serve as anchors also prevent a deeper insertion.
With the right tips, the soundproofing and insulation is remarkable.
The combination of all these elements makes them very compatible with day-to-day use, use in public transport (metro, bus), for light outdoor sports and, of course, also for use at home.







The Reecho SG-03s have a decreasing W-profile, which means that the main emphasis is placed on the sub-bass, while the mid-highs are slightly behind and finally the treble takes the last position in overall presence. Their very powerful low end might lead one to think that these are just another IEMS for bass-heads, with nothing to contribute, but this is not the case. Of course, we must highlight the great work of the low end (spectacular that this is sold for 69$) because I find that it combines power and speed, punch and containment typical of superior models. The emphasised high mids have great clarity and bring a high technical level to the sound, giving it a lot of precision, commendable cleanliness and separation. I still think there’s a BA hidden out there and they don’t want to say it? Because the vocals are closer than the frequency response would lead you to believe, as well as the details. Then, the treble is tuned to appease those high mids, but without losing brilliance, or descriptive power.





I must start at the beginning, that is, in the deepest and most emphasised area, the sub-bass. The first peak of the W starts here, and how! The SG-03’s move with exemplary authority in the sub-bass, exuding power, energy, punch and impact, as well as an unusual sense of separation and air, a sensation that extends to the rest of the range. Then, as the frequency rises, the bass cleans up and drains, allowing it to fluidise the lower range, into the midrange. This is how the mid-bass feels without a hint of bloat, very well distilled, giving rise to a sensation of a fast and easy pick-up zone, which gains in dynamics and decay. The result is a very dry, consistent and appreciable hit, clearly oriented towards the deeper side. The definition is imposing: to listen to this model blindly, without knowing its real value, is to fall into a trap that will make us assume that these are superior IEMS. But in reality, there is no joke in their sound, everything is real and realistic, natural, inherent, spontaneous and with a lot of nerve and temperament. Despite the depth of the low end, there is no darkness. The texture, being a fast driver, is not very extensive, but it has an innate, high-resolution roughness, with a descriptive ability that allows notes to be picked out with great precision. In no case is there any confusion or overlapping of planes, quite the contrary: the richness of its execution generates a neatness that can be observed with great clarity when it is associated with analytical sources. It is in this case, when its great potential can be appreciated and all its virtuosity can be observed in this area. Very commendable.





The midrange continues to enjoy that excellent cleanliness, thanks to the great respect that the low end processes in this range. It is clear that, as usual, raising the power at the sub-bass end ensures a much cleaner midrange, without its theoretical distance feeling overbearing. It is also true that the rapid emphasis on the high-mids and first highs helps the vocals to sound much more accompanied and complete than one would expect. This is how everything is well calculated, so that the mids enjoy a greater importance, managing to balance the overall sound. Despite all this, there is no hiding the fact that the central range is not very full-bodied or dense. The aforementioned cleanliness and clarity offer a lighter, darker background sound, with a texture that is not very present, but with easily perceptible detail, thanks to the SG-03s’ high level of resolution. Not that I can say that its tendency is complete analytical, but it is certain that its technical capabilities help it to lean towards this direction. The smoothness of the voices contrasts with the accentuated nuances of their edges, which, in turn, are very well integrated and differentiated from the rest of the instrumentation details. This conjunction is paramount in generating a musical richness, which one might think comes from a finely tuned BA. But in the background, there is that more organic, softened sound in the extreme, which inevitably comes from a high-performance dynamic driver. As a result, the whole feels very musical and spacious, with a more concave central recreation, where details float, well placed, in a transparent, evocative and dynamic atmosphere. This is how IEMS, powerful in its low end, pays respect to the midrange.





The upper zone is based on a lightning start and the classic quick cutback. It’s the traditional way of creating sparkle without losing control. And that’s how it happens on the SG-03s, and it works very well on this occasion, if you’re not a treble-head. The initial flash shimmers with moderate force, offering a well-resolved sparkle, controlled in extension and tuned without losing naturalness, but with the appropriate brightness. In this way, the nuances feel explicit, but not elongated. The brightness does not spread, remaining somewhat more restricted in that initial stroke. In this way its width is thin, without further development, sharp but not overly so, thus trying to keep the sibilance at bay, but without the sound becoming nuanced or flat. The result is a slightly splashy edge, whose radiance is quickly mitigated. Perhaps, this effect limits the extension on the cymbals, preventing a more natural and calm development in time, accelerating the decay and disappearance of harmonics. In this sense, the extension and the amount of air can be slightly compromised, but we must take into account where we are, to value the area in its right measure. And it is at this point that the treble becomes a very valuable complement to complete the lower ranges and put itself at their service. It is clear, then, that the upper zone is free of fatigue and its persistence is moderate, which helps to provide a good level of clarity, without exceeding neutrality in this sense and helping to prolong listening time.



Soundstage, Separation


The scene feels eminently frontal, moderately concave, where the voices appear more centred, in the middle distance. Depth trumps height. The spatial recreation is not very holographic, nor three-dimensional, nor enveloping, but it enjoys good width.
The level of separation and transparency is outstanding. The amount of air is good, but not so much as to provoke a more vaporous and ethereal feeling. The recreation is realistic in shape, but remarkably detailed and rich.
The SG-03s rely on providing a greater sense of separation, recreation of nuance and micro-detail, rather than on generating a larger scene or more precise or explicit positioning. In this respect, they are technically high marks, while in the imaging department they fall a little short of that mark.





TFZ Live 3


The Live 3 is an IEMS currently priced the same as the Reecho SG-03. Construction clearly falls on the side of the SG-03s, as they are as close to a tank as you can get in this range and immediately above. The profile is also similar, although the Live 3s have an extension in bass power that extends more towards their midrange. This makes the lower area denser and thicker. In that sense, the SG-03s are more accurate and faster, though not as powerful and complete. The low end of the TFZ is more noticeable in the other ranges, being above them. Not so with the SG-03s, as their voices stand out and sound clearer, more vivid and present, with a brighter, more detailed and more nuanced profile. Comparatively speaking, in the mid-range, there is a power shift between the two IEMS. If in the low end, the power was higher in the Live 3, in the midrange it moves towards the SG-03. This is how the midrange has less prominence in the TFZs, showing a somewhat more opaque, sparse, neutral, somewhat darker and with less dynamics.
The only improvement the Live 3 has over the SG-03s in this respect are the male vocals, which can sometimes sound fuller and more textured, although with less detail and nuance. Whereas on the SG-03s, they can be observed as thinner and colder in such cases. Although the instrumentation definitely benefits from the better technical virtues of the Reecho, its better analytical capabilities giving it a better representation, richness, dynamics and also presence.
In the upper range, there is more relative presence in the Live 3, but not more definition. The incidence of the mid-highs is lower, but the first treble is felt a little more. The problem is that the SG-03s’ ability to improve the exposure of the range makes their treble superior, in terms of dynamics, speed, resolution, definition and noticeability. The Live 3’s darker sounding feel means that the Reecho’s possess a greater amount of air, clearer separation, a wider soundstage, more headroom and a more accurate representation.
It is clear that the Live 3 cannot compete in construction and durability with the Reecho, but it is worth noting that they are quite comfortable and weigh less. They don’t have the complex and precise fit of the SG-03s, but they are very comfortable and sometimes this can be preferable. The level of isolation is superior in the Reecho SG-03.



Hidizs MS2


The MS2s are another great example of how IEMS in this range are improving in quality, giving a sound that was initially reserved for higher price points.
In broad strokes, the MS2s are like the «sweet and balanced» brother of the Reecho MS2s. In the midrange and treble there are more similarities than it may at first appear. And the low end of the MS2s is not as weak as it looks, comparatively speaking. There is good bass punch in the Hidizs, great texture, speed and remarkable technical capabilities in the lower range. But of course, all of that is also in the Reecho, with a nice plus of power, energy and presence. I just think the texture could be more descriptive in the MS2s, as it is perhaps more present because the lower energy makes it more perceptible.
The mid-range of the MS2s is clearly more balanced, with a more neutral and less bright tone than the SG-03s. Thus, female vocals have more body, density, but less sparkle. On the Reecho, everything is more emphasised, even the details. The Hidizs are quieter, with a more homogeneous and warmer midrange. The tone is slightly darker, but this effect brings a fuller body to the voices, especially the male ones, making them more complete and closer. In general, in the Hidizs, the central range is tuned to show off and everything is very well measured to distribute its prominence above the rest. Without being a mid-centric IEMS, the work of the rest of the ranges is very much in favour of helping the middle part. And in this sense, despite the great achievement of the SG-03s in this respect, one has to surrender to the greater musicality and complexity of the Hidizs’ mids.
The Reecho have a brighter profile, although the tuning is similar, the treble rises more in presence, which makes them crisper and thinner. In the Hidizs they are more restrained and do not escape the script of their homogeneity. Thus, there is more sparkle in the SG-03s and a higher penetration rate in the first half of the treble. However, the greatest extension falls on the side of the MS2s, which enjoy more air and a more elongated harmonic level. When it comes to depicting detail, the Reecho’s greater sparkle helps them to extract even more hidden micro nuances, without being overly analytical. The more homogeneous look of the MS2s works against them in this respect, comparatively speaking. There seems to be a higher level of transparency and separation on the Reecho, while the scene seems to appear more complete, better defined and placed on the MS2, with a more three-dimensional feel.
In terms of construction and ergonomics, the MS2s are very similar to the Live 3s, but even lighter. It is clear, then, that everything said about the Live 3 can be repeated here, except for the lighter weight point.
I would like to point out that both IEMS are great examples of very well-finished products with excellent sound and that only our preference for one profile or the other can decide which one we like better.





It may be too early to say, but I’ll go out on a limb and say that Reecho has launched one of the products of the year, under $75. From the outset, the construction and design is colossal, something distinctive and emphatic, with great ergonomics to boot. And the visual aspect, on this occasion, gives a clue to its sound: punchy and sharp, but in a good way. With a W sound based on an impressive sub-bass, a mid-range that has superb clarity, separation, good presence and sparkling highs that provide plenty of detail and a high level of micro nuances. It’s a seamless, technically remarkable sound, with superior speed and dynamics, and a highly enjoyable profile. Honestly, I think the Reecho SG-03s can be a clear reference in this price range.



Sources Used During the Analysis


  • Tempotec Sonata E35
  • Xuelin H7
  • E1DA #9038B
  • Earmen Sparrow
  • Hiby R3 Pro
  • Hidizs DH80S
  • Tempotec V1-A