Dynamic Analogy

Ratings

Pros

• Quality, tuning, texture, power and presentation of the low end, focused on the sub-bass, resulting in a clean and smooth transition to the mids.
• Nice, clear, vivid and realistic w-profile. Good all-rounder.
• Great ergonomics and fit. Light weight.
• Attractive and realistic timbre.
• Filters are versatile, both are usable and can be safely stored in the carrying box.
• Near excellent treble presentation, quite linear and extended.
• Good cable that matches the characteristics of the IEMS profile.
• Choice of 4.4mm balanced plug.

Cons

• The lower part of the mids is slightly recessed.
• It is not the best set in technical aspects such as detail and image, but it is quite competent in its price range.

Purchase Link

https://letshuoer.net/products/letshuoer-d13-dlc-diaphragm-dynamic-driver-iem-moving-coil-headphones

Link to the Store

https://letshuoer.net

Introduction

Letshuoer continues to move forward and is back with a new model in the slightly higher $100 range. This time it is an IEMS with a dynamic driver with a 13mm DLC diaphragm, created by the brand itself. As points to highlight, it has two mouthpieces to tune the sound and an original and very comfortable capsule design. As usual, the supplied cable is of high quality and can be chosen with SE 3.5mm and BAL 4.4mm plugs as standard. Of course, this should be the norm, as balanced outputs are very common nowadays and are becoming more and more popular, both for more power and for higher quality and better sound performance. Although, it is true that this new D13 needs little power to shine, as it has a high sensitivity and a low impedance of 16Ω.
In my opinion, the D13s are the dynamic alternative to the famous S12 planars, with an added sparkle in the bass and mid-high range, with the possibility of slightly tuning this area, thanks to the mouthpieces. Let’s see why I think so.

Specifications

• Driver Type: 13mm dynamic driver with DLC (Diamond-like Carbon) diaphragm.
• Driver construction: High-performance Neodymium N52.
• Production process: CNC.
• Capsule Material: Aluminium.
• Frequency Response: 20-20kHz.
• Sensitivity: 105±1dB.
• Distortion: 0.16%±0.1.
• Impedance: 16Ω.
• 2 interchangeable filters for mid-high and treble tuning.
• Jack Connector: Choice of SE 3.5mm or BAL 4.4mm.
• Cartridge Connection Type: 0.78 2pin.
• Cable: 0.05mm * 216 high purity copper wire.

Packaging

The Letshuoer D13 comes in a dark, elongated box with contained dimensions and a size of 152x104x68mm. On the front side you can see a picture of a capsule. At the top left is the brand logo in grey letters. At the bottom left is the name of the model, in the same form. Finally, at the bottom right is the Hi-Res Audio logo. Behind it, still in grey letters, are the specifications in several languages, the brand name, the holographic warranty seal and the certifications that the product has. Once the cardboard is removed, the box is still black, with the brand name on the horizontal edge of the box. Once the lid is lifted, a catalogue of the brand’s products appears and the capsules are encased in a large block of black foam. Underneath are instructions and several cards. Finally, there is the black, oval, zipped case, which contains the rest of the accessories. In a nutshell:

• The two D13 capsules.
• 1 x 0.05mm * 216 high purity copper wire, 4.4mm balanced 4.4mm plug and 2Pin 0.78mm connectors.
• 2 interchangeable gold plated nipples.
• 3 pairs of black silicone tips.
• 3 pairs of white silicone tips.
• 1 catalogue of the brand’s products.
• Instruction manual.
• Product certificate.
• Warranty card.
• Warranty booklet.
• Zippered case.

The oval case has already become a brand classic. It is robust and very pleasant to carry. This is a welcome accessory, because other brands are moving away from this type of case and are using fabric pouches that do not fulfil their main function of protection. In addition, it has a small grid to store the mouthpieces safely. Otherwise, two sets of tips are enough, a good copper cable and the usual documentation. Quite acceptable.

Construction and Design

It may seem that the IEMS world has already seen a lot of shapes and I like the classic semi-custom shapes. But I consider myself open to any design that is effective. And Letshuoer has succeeded with the D13. The capsule is a wide aluminium disc, which can be chosen in two colours: dark grey and blue. Attached to it is a cylinder containing the 2Pin 0.78mm connection, inside a translucent plastic piece that protrudes from the inside of the cylinder to indicate, with a letter, the channel, as well as its red or blue colour. The inner side of the capsules has an elongated and inclined mouthpiece. It is basically a cylinder with two diameters, a central and smaller one, and another at the edge, which is the interchangeable mouthpiece. In the centre of this inner face there are already three holes, the central one being oval. On the edge of the disc, the brand name, model and «207» can be read in white letters. The outer face is not flat, but has a shallow disc of the same colour in the centre. On it are three red grooves in the shape of a semicircle, the length of which decreases as they approach the centre. And on it, a smiley smile-shaped indentation. It is certainly a design that may remind us of other IEMS, but the brand has given it a distinctive and differential touch.
The cable, on this occasion, is made up of 4 strands, a total of 216 wires of 0.05mm of high purity copper. Its colour is dark copper. The plug is classic 4.4mm gold plated, with a cylindrical cover, with the brand name written around it in white letters. It has a raised ring for a better grip. Its colour matches the capsule. The splitter piece is a simple cylinder, just like the 2Pin connectors, which only have a lowered ring and a plastic disc in the same colour as the one containing the 2Pin sockets of the capsules. It has a transparent plastic coating to shape the cable over the ear. Finally, the pin is a small but effective translucent plastic cylinder.
As mentioned before, the mouthpieces are interchangeable and are screwed into the body of the IEMS. There are 2, one has a golden grille, which produces a higher pitch. The other one is silver-plated and the sound it produces is more nuanced, with more bass.
All in all, a good, elegant and very, very effective design.

Adjustment and Ergonomics

Previously, I have highlighted the efficiency of the design and this is something that is noticeable in both fit and ergonomics. The capsules are medium sized and fit very well. Once inserted, they protrude very little and the cable fits nicely behind the ears. The nozzles have a very well designed inclination and fit my ear canals without any problems. The insertion can be medium, but also shallow. The capsule parts do not rub against my ears and remain floating, although very static. The assembly they form with the over-ear cable allows for minimal rotation, the fit is durable and the weight is very low, despite being made of metal. A great design for a great fit and better ergonomics.

Sound

Profile

The profile of the D13 has a slight tendency towards a tiny w, which can be more projected, depending on the mouthpiece used. The gold mouthpiece subtly lowers the bass, emancipates the high-mids at 2kHz and raises the treble slightly to end up with the silver filter in the air region. Initially, as a bass lover, I usually use the bass filters and, at first, I liked them very much. On the other hand, my initial feeling with the gold filter was that I found it a bit uncontrolled. So I did all the burning with the silver filter. But when it was over, I went back to the gold filter and found that the tuning was more complete and balanced. With the bass filter the profile is smooth, perhaps too smooth, from the mids onwards. Totally safe, but with little brightness. The return to the gold mouthpiece brought light, better detail, sparkle, while the loss of bass is negligible, considering that the Letshuoer D13s with their 13mm DLC filter are a real powerhouse in the low end. I don’t consider them for bass-heads, but they have an unabashed power not without quality and great technical skills. What amounts to a great modern dynamic driver, with a touch of excitement and fun in the low end.
For the following impressions I have focused on the gold mouthpiece.

Bass

It is undeniable that the Letshuoer D13s are enjoyable from the low end. The moment the LFOs are reproduced, one realises the power of this driver to execute the lower range. Its vibrant texture and roughness stand out, so that these waves become perceptible to our ears. That’s right, the D13’s bass is the kind you feel on the skin of your inner ear, while its texture advances through the ear canal, until the thump explodes against your eardrums. The sub-bass is like a persistent whisper, whose rumble never ceases, it is at the audible and sensory limit, generating an abyssal depth, full, natural and organic. I still maintain that bass should be reproduced by dynamic drivers and the D13s are the paradigm of this statement.
After the emphasis on the sub-bass, the mid-bass is adequate, the zone progresses gently descending towards the mids, making the range full, without losing density and keeping the transition clean. Technically remarkable, the speed of execution accelerates with the passage of frequencies, gaining agility as it approaches the central range. The punch becomes more concise, sensory transcendence is lost, dryness is gained and the decay is more ephemeral. However, the texture is still recognisable throughout the range and it is something that adds naturalness and an organic/analogue feel that elevates the overall appeal of the zone, comparatively speaking against other similarly priced IEMS. All in all, the D13’s bass is the culprit in keeping them in my ears for a long time, aided by their great ergonomics. The intonation, timbre, texture, power, loudness and technical qualities of the bass, bring the D13s into my personal enjoyment zone in a very appropriate way, bringing a smile to my face and elevating the listening pleasure of my electronic music collection. They have hit the nail on the head.

Mids

If there is one thing I like almost as much as the bass, it is the midrange. That’s why I can’t conceive of a good sound if there is no representation of the midrange. But in reality, all ranges are important, because I don’t see a music without detail and brilliance as logical either. It is clear that if one wants to emphasise a band, it is possible. But the tricky thing is to find a balance over the whole audible range. Not that the D13 is a paradigm of such balance or flatness, but it is not far from an acceptable profile in this respect, but with more than just nuance. The bass is a testament to this, and so are the mids. If we look at the D13’s graphs, it moves around a 10dB variation between 20Hz and 10kHz, the range where most musical information is concentrated. Is that a lot? Quantitatively yes, but audibly not really. In no case is it an unbalanced or polarised profile, but rather the D13s have a smooth, harmonious curve, which can be varied with precision thanks to the filters. One adds sparkle by adding a little pinna gain and first treble, the other smoothes this part out and subtly excites the bass. The balance is won or lost depending on the audience. In my opinion, I could define tuning as a set of sensations and a boost in some key frequencies can be a success. And so it has been here. Following in the footsteps of an exemplary profile like the S12, Letshuoer wanted to follow the pattern by means of a much more traditional sound, as produced by a dynamic driver and to take on the technical capability, thanks to new generations of materials, that make it possible for this type of driver not to lose out to new technologies. Where it is possible, a little more sauce has been added, and where it is not, nothing. This is how the mids are described. The transition between the bass and the midrange is smooth, without haste but without pause. The sinking is relative, if the music presents bass, its more stellar presence can send the vocals into the background. This is where the enhanced technique of a large dynamic driver serves to recover detail and achieve a shared presentation, rather than a diluted mix. In this sense, the coexistence is respectful, even though everyone knows who the big brother is, it’s a good family and whenever possible, the little ones in the house will be highlighted. And this happens when the music is more focused, with less bass. The vocal range has a remarkable representation, both nuances and details can be perceived. There is no disdain or disregard for the central range, only that its presence does not have the presence of the deeper bass. And, in fact, this only happens occasionally in the first half, because in the second half, the protagonism returns, but in a controlled way. I would like to say that the chosen excitation point is critical and I know that in other headphones it has failed. Here I can safely say that it has been a success, so the choice has been a wise one. The result is a measured emphasis, which can be chosen by the user, to add vibrancy, clarity, excitement, sparkle, brightness, brilliance and clarity. But you can also choose calm and restraint to gain control and dissipate harshness. I’ll stick with sparkle – who would have thought it! And I applaud the way it combines a range that varies from soft to excited, but never lacking in information, vivacity, colour and, why not, naturalness. Clearly there may be a favouring of female vocals and guitars, but there is enough fullness to swell the male voices. And, as I said before, there is technical quality to enrich both instruments and voices, as well as adding texture.
To conclude, I would say that the midrange is not fundamental, but it is not a secondary range either, and it also has a playfulness that allows a well thought out dressing, that allows correcting aspects or enhancing them, depending on the music you want to listen to.

Treble

This is not a classic high end and I like that. The D13s move away from a V-curve and towards the S12s’ planar approach of adding flatness to the treble and stretching it gently. The dynamic driver may not hold up to the new technology, but it does achieve a very full and natural representation of the treble. First, they start from a comfortable elevation that adds security, without losing presence. And again I repeat, at the right point. And if not, that’s what filters are for. Second, there is no control zone as such. So there is no frequency clipping, but a more realistic exposure. This is how you get a measured, but also fuller brightness. The high notes are not ultra-fine, but have a certain body, but with an excitement that can range from pleasant to vivid. Again, the level of information is very important: by presenting a smoother range, information is not omitted and the result is more realistic, even organic and sparkling. Third, the descending exposure helps to limit sibilance. Either that, or the Silver filter, for sensitive ears in this respect. Lastly, the air zone is where the driver’s limit can be glimpsed. But hey, it’s not so bad! In summary, I think that the treble is quite enjoyable, it has the quality that the rest of the ranges possess and the necessary extension to represent the music with clarity, realism, detail and harmonic capacity, generating a pleasant timbre and very close to the target.

Soundstage, Separation

I could define the D13 scene as quite pleasant. I don’t feel it is average, though not spectacular either. The splashy details bring the elements closer together, but there is a noticeable level of depth and laterality. There isn’t an out-of-head feel, nor is there too surrounding. But there is enough air to generate a realistic, calm, detached image with just enough of a dispersion-to-order ratio to sound appealing, natural and moderately expansive. All this is aided by a good technical level to offer significant resolution and definition, allowing for fine notes and details, and a sensitive space between them. In this way, separation is appreciable and any hint of congestion is removed, offering an orderly, natural, but not too pronounced or focused positioning. The D13s are effective in this respect, nothing superior, but they offer a little more than you might ask of them for their price range.

Comparisons

Letshuoer S12

I don’t have a reference curve on my SquigLink website. But I think I already commented in the S12 review, that their frequency response would be very close to that reference. Perhaps my preferred curve would be somewhat flatter. However, I also came to the conclusion that despite my preference for that curve, the S12s had room for improvement. And, to some extent, the D13s bring some of those improvements. First, the loudness and quality of the dynamic bass. I still prefer the timbre, colour and texture coming from the classic drivers. It is also true that they have less mid-bass, adding cleanness to the first half of the sound. Another plus is that sparkle in the mid-highs, which gives it more brightness and luminosity, as well as «fooling» the listener with a bit more explicit detail. Finally, where the DDs don’t reach is in the high end, and it’s here that the extension into the air zone outperforms a well tuned and stretched dynamic driver. As I mentioned in the treble section of the S13, the best thing is that its tuning in this area is similar and achieving this should not have been easy, when in fact the result is very good.
On a physical level it seems that the S12s are slightly heavier than the D13s. Their cable is thicker and silver plated. The D13’s cable is made of copper and is thinner. The ergonomics, while not bad on the S12s, are superior on the D13s. The S12s sit more in the pavilion. But both the subtly lighter weight and the smaller, rounder shape make the D13s fit my morphology better.
Let’s leave the graphical considerations aside and return to my sonic perceptions. For the comparison I used the gold filter on the D13s. The bass of the S12s feels bigger, more present and extended into the midrange. The D13s, more focused on the sub-bass, release mass and feel more uncluttered. In the S12s the bass is heavier, also fuller. But I prefer the D13’s agility, colour and texture.
In the mid-range the differences are large with the gold filter, while they even out with the silver filter. But going back to the gold reference, the first impression is that the D13s have more light and clarity, giving a feeling of greater separation, even detail. The sound is calmer, more relaxed in the S12s, the low-mids have more body and also more density. The mids are thinner in the D13s and especially the upper mids. The excitation of this area is noticeable in the D13s, which can be smoothed out by changing the filter. It is clear that the timbre changes and individual taste will tip the balance one way or the other.
There are also differences in the treble. The sonority is different, although the initial presentation is similar. Then, the execution, the timbre, the decay do the rest. This is where the S12s show their power, although they are also more present in the higher areas. They also improve the sensation of air.
Neither of the two IEMS are detail specialists. The resolution of the S12 is good, but the D13s also generate a good sense of definition, which can be fictitious because of their more excited tuning. But there are those details that come from that better clarity. At the stage level it is somewhat similar, the denser sound of the S12s offers a bigger wall, a wider sound in general. Their oval image has more height and spreads better laterally. The D13s, with their better clarity, seem to present a less cohesive sound and with more gap between notes, improving the sense of separation and darker background.
The S12s are still good, but the D13s are a dynamic alternative that doesn’t lag behind them for less money, being much easier to move, with better ergonomics and a performance that can be superior in some areas. A great job.

Conclusion

I think the Letshuoer D13 had a very difficult job to do: to be the successor of the acclaimed S12. And I must admit that the brand has done it very well. In my opinion, the D13s have superior ergonomics, are lighter in weight and add a couple of filters that tone down the sound at two critical points, in order to reach a wider audience. My guess is that to ensure some success, the D13s don’t deviate much from the smooth w-curve set by the S12s and I think they have based their tuning on them, albeit with a couple of tweaks: one is more subtle and the other a little more pronounced. Overall, they have achieved a great low end, more emphasised in the sub-bass, adding more cleanliness in the lower range and a smoother, finer transition. With the dynamic driver, they have gained in texture and sound pressure during the strike. The sound is thinner in the mids, also brighter, giving a greater sense of clarity and liveliness. The timbre is thus more natural/organic, but still on the natural/organic side. In the upper range the work is very good and you can tell that Letshuoer wanted to stretch the dynamic driver as if it were the S12s. He has not succeeded, it is clear that the planar driver has more range in this respect. But the tuning is also very good, quite linear, with a full representation, without control zone, but well measured and without losing that soft but present character. In this way the treble is realistic and extended. It is not a prodigy in detail, resolution, scene, positioning and other technical and representational issues, but it has nothing to envy to the direct competition. Finally, it has great sensitivity and combined with the great fun factor, versatility, ergonomics and weight, it is a very, very appreciable IEMS for everyday use. All in all, I think they are very attractive all-rounders, whichever way you look at them.

Sources Used During the Analysis

• TempoTec Variations V6.
• Hidizs AP80 PRO-X Red Copper Limited Edition.
• Burson Audio Playmate.
• xDuoo XD05 BAL.
• Earmen Colibri.