Hidizs ST2 Nebula

Introduction

Hidizs is on the bandwagon of combining IEMS with a DSP cable with an integrated DAC-AMP that replaces the audio connector. With today's technology of reducing converter and amplifier devices, it is easy to combine these tasks. This is not the first model I have reviewed with this in mind. This time, it has an integrated microphone and is a more universal DAC/AMP, with 2Pin 0.78mm and MMCX terminations. As Hidizs comments, this cable was born as a response to the limitations of the Bluetooth system in terms of power, high resolution audio, better sound quality, compatibility with many more devices without the need of a Bluetooth emitter, etc. The Hidizs ST2 PRO Nebula cable has the ES9281AC PRO DAC chip, with a power of 70 mW at 32 Ω, a sensitivity of 108 dB and a very low distortion of only 0.0012 %. The advantages are obvious: higher power, zero latency, wider bandwidth (20 Hz-40 kHz), 32-bit resolution and support for PCM formats up to 384 kHz and native 64/128 DSD.
Along with this cable, capsules made of resin and aluminum alloy are supplied, incorporating a dual dynamic driver with a 10 mm PU+PEEK composite diaphragm. The IEMS have been tuned according to the H-2019 target curve for accurate audio response. They offer balanced tonality, powerful bass, rich mids and moderate high-frequency extension, meeting Hi-Res audio standards for a HiFi quality listening experience. HIDIZS liquid silicone earplugs are made of high permeability liquid silicone and feature an ergonomic design that fits perfectly in the ear canal. The custom pouch provided by HIDIZS ensures safe storage and extends the lifetime of the ST2 PRO Nebula without worry.

The Kickstarter launch date will be December 19, 2024, at 10:30 AM (EST):

• ST2 PRO Nebula (Super Early Bird): $39.00 (limited to 500 units).
• ST2 PRO Nebula (Early Bird): $49.00.
• ST2 PRO Nebula USB-C DSP 0.78mm 2-pin/MMCX Headphone Cable (Early Bird): $36.00

Specifications

• Driver Type: Dual dynamic with 10mm PU+PEEK composite diaphragm.
• Frequency Response: 20Hz-40kHz
• Sensitivity: 108dB
• Impedance: 32Ω
• IEM design: resin + aluminum alloy engraving.
• Connector cable: USB Type-C.
• IEMS capsule connection type: 2Pin 0.78mm.
• Cable connection type: Choice of 2Pin 0.78mm/MMCX.
• Weight: 7 grams approx. (excluding headphone cable).
• Cable weight: 16 grams approx.
• Cable color: Silver-Gray/Black-Blue.
• IEMS color: Transparent white/transparent black.
• Cable DAC: ES9281AC PRO
• Chip Architecture: HyperStream®II QUAD DACTM Architecture
• Resolution: 32-bit.
• Sampling Rate: PCM 32-bit/384 kHz. Native DSD 64/128.
• MQA support.
• Distortion: 0.0012%.
• SNR: 118 dB.
• DNR: 122 dB.
• Separation: 63 dB.
• Output power: Up to 70mW+70mW at 32Ω.
• Plug type: USB-C (Type-C/ USB Type-C) (Only compatible with iPhone 15 and later models) (Compatible with 99% of devices with USB-C output port).
• DAC case material: Aluminum alloy + transparent resin.
• Cable core material: High purity oxygen-free copper.
• Cable splitter piece: Aluminum alloy.
• Cable sheathing: Textile yarn.
• Cable core specifications: 4 Wires 260 Cores.
• Diameter: 4mm.
• Length: 1.2m.

Packaging

The Hidizs ST2 PROs come in a nearly square black box measuring 114x104x38mm. On the main side you can see the Hidizs logo in the upper left corner and the ESS, DSD, MQA and Hi-Res Audio logos in the upper right corner. All this is printed with holographic ink. In the center is a realistic photo of the capsule. Below is the model name in large letters and a description in smaller letters, also in holographic ink. On the back side are the specifications of the set in several languages. Around the edges is more information, as well as a label with the model option, in this case transparent black. After opening the lid, the capsules are in a foam mold lined with black cardboard. At the top is a cloth strip so that the first layer can be removed. Underneath is a black plastic bag. The accessories are inside. At the bottom are two cards. In summary, the complete contents are as follows:

• 1 ST2 PRO.
• 3 pairs of ergonomic white silicone ear cushions, sizes SxMxL.
• 1 USB-C to USB-A adapter.
• 1 HIDIZS bag.
• User manual.
• Warranty Card.
• Product Quality Certificate.

It still carries Hidizs' synthetic leather pouch instead of a zippered case, as is already the case with other, even more expensive, models that only include a set of accessories. But the USB Type-C to Type-A converter is appreciated. Good.



Construction and Design

The capsules have a semi-custom shape and are made of resin, except for the outer part and the mouthpieces, which are made of aluminum alloy. The resin is transparent, so you can see the inside, the wires and the driver. The 2-pin, 0.78 mm thick, oval-shaped connection plate is located on the bottom edge. On the edge, in silver ink, you can read “Hidizs Nebula” and the marking indicating the channel. The mouthpieces are metallic, golden and have three diameters: base (6.6 mm), central part (4.8 mm) and crown (6 mm), and an approximate height of 5.5 mm. There is a hole in the center of the inner face.
The DSP cable is constructed with four wires and 260 cores. It is composed of two braided strands with black and purple textile coating. The metal parts are dark gray and made of aluminum alloy (DAC/AMP sleeve, splitter piece, cylindrical microphone container and button). The DAC/AMP case is oval, flat and has windows through which you can see inside the circuitry. The top face reads MQA on the end opposite the USB Type-C connector. On this side there are several LEDs inside that allow to generate various colors. On the opposite side you can see the ES9281AC PRO chip. Resin has also been used for the transparent parts of this connector. The cable has over-ear guides thanks to a transparent semi-rigid sheath. The connector sleeve is made of slightly angled transparent plastic. The letters indicating the channel are embossed and almost imperceptible. The cable has a branded Velcro strap.
The design of the capsules is quite conventional, with a transparent resin, and the difference is in the external aluminum alloy plate on which the brand and its logo are displayed. On the other hand, I like that the cable has a textile covering that gives it a little more resistance, comfort and softness. The metal parts enhance the look of the DAC/AMP cable, as do the transparent windows that allow you to see inside the circuitry. Other details are the colored LEDs, the USB adapter and the cylinder with microphone and button, which make the product an all-in-one device to replace any Bluetooth system. The next step should be a background noise suppression system for the microphone.



Adjustment and Ergonomics

The most significant thing about the capsules is their low weight of only 7 grams. The semi-custom shape makes for a great fit, but the slightly thicker mouthpieces and the angle to the ear canal can make it difficult to choose the right tips. I have tried my large foam-filled tips with no problems. However, I have found that the sound profile calls for tips with a wider channel to gain clarity and lighten the bass. For this I have used ultra large blue silicone tips, with low profile and large inner core. A good seal is achieved, although the isolation level is not so high. The set is very comfortable, but with these silicone tips the fit can be a bit more critical, as small variations in position can alter the bass response. It is not the fault of the model, but it is true that with my big tips filled with homemade foam, I get a very high bass boost that alters the natural response of the set in an undesirable way. I have looked for alternatives like the Tangzu Tang Sancai Narrow Bore or the black Penon Liqueur Silicone Eartips, but the ones that have worked best for me are these, much cheaper (blue color) and all in extra large size.

https://es.aliexpress.com/item/1005004615505310.html



Sound

Profile

The Hidizs ST2 Pro are a cable-integrated DAC/AMP assembly plus IEMS with a classic V-profile. According to the website, their profile is aligned with the H-2019 target audience. In my opinion, the ST2 Pro's enhance more mid bass and less sub bass. It is also more noticeable in V, with a more sunken midrange and a somewhat steeper rise towards the treble. Then there is a slight area of control in the first treble and an extension that pales in the air area.
Overall, the set is somewhat more emphasized in the bass, with that wide curve in the low area. That's why I've looked for some tips to lower the lower zone and favor the clarity of the whole.



Bass

Bass presence can be noticeable with some tips, but it is an easily correctable problem. I have used low-profile, wide-channel tips to promote separation, clarity and transparency. In this way, the bass does not appear saturated or overly boomy. They offer a clear sense of texture and low-medium speed. They have a moderately compact punch with good retrieval. The bass is rounded, with a sub-bass that is neither too pronounced nor too deep. The low-mid bass is the protagonist, feeling powerful and wide. It has plenty of volume and occupies considerable space, almost with a tendency to overpower.
In the very low frequency pure tone test, the limited emphasis on the sub-bass is noticeable. The audible lower note is barely perceptible, both aurally and sensorially. This detracts from its depth and accentuates its more physical character, centered at 60 Hz. As frequencies rise, the bass becomes more powerful, with a subtle color and wave-like appearance. In reality, this translates into a bass with a rough surface, expansive, powerful and extended, more noticeable than dark and physically powerful, with an obvious and forceful punch.
In the dirty, unfiltered bass test, it is noticeable that the lightness of the sub-bass brings a bit more color than sensory physicality to the sound. In any case, control is better than expected despite the somewhat more conventional sonority of its V-profile. The level of resolution is somewhat limited, although it does its job well in following the bass lines. Its sound is rounder and less defined, which gives a feeling of powerful bass, although relatively simple and not too tight.



Mids

The midrange starts warm and with some strength marked by the extension of the bass. This gives it some physicality in the lower mids and a more powerful base. The rapid descent into V makes the male voices thinner. The sharper they are, the more remote they feel. There is that sense of central hollowness that characterizes this profile. However, the instruments are well represented and are perceived whole and full.
The level of resolution is still on the soft side, appearing more rounded, with a blunt profile, bringing a rather relaxed sense of musicality and with a visible level of macro detail. The central micro detail is perceived as compacted, very attached to the surface, implying a medium level of layering and not too much depth. This micro detail is intuited, but it is not defined in a particular way, but is part of a somewhat thicker and more cohesive line.
The female voices are closer, although their base is not as marked; it is somewhat the reverse of the male voices. However, they are also perceived as warm and round, without too many nuances and with a soft aspect that limits sibilance.
In summary, the mids are musically pleasing, somewhat depressed in their center, cohesive, without too much depth, but remarkably resolved at the macro level.



Treble

The treble begins with a high point, after a slight zone of control, and a second sparkle appears that brings vivacity and a somewhat sharp extension. The level of refinement is medium, relatively pleasant, not too marked, but with a more incisive edge at times. There is a great deal of energy, though it feels somewhat limited in the air zone, already showing drier and more compact. But, although that energy is not predominant in the mix, it is so that the whole does not appear dull, dark or dull. The upper zone has its own entity and shows that it exists on its own and not as a mere accompaniment to the whole. In this way, both the high notes themselves and their harmonic contribution benefit the ensemble.



Soundstage, Separation

What strikes me most about the sound of the ST2 Pro is the volume of the bass. This feature enhances the sense of spaciousness and extension of the soundstage. On the other hand, the layering is simply good, with somewhat cohesive and compact mids. Details are perceived on the surface, while smaller details in the background come closer to it and connect, losing some ability to describe themselves with more rigor and definition.
The scene has good laterality, a level of closeness of the volume more noticeable than the depth itself, and an adequate height. The image is eminently frontal, connected, harmonious and conjunctive, without too much sensation of individuality. In this way, a warm, musical, melodious and soft sensation prevails, which moves away from any forced over-definition. The result is a fairly natural level of separation, with a sense of luminosity, transparency and clarity sufficient to prevent the whole from becoming thick, dark or overly nuanced. I don't miss light, brightness or more transparency. It does lack a little more layering, layer generation and a more evident background.



Comparisons

KBEAR Robin

I like to compare IEMS with similar profiles. Although, in this case, it would have been more appropriate to make a comparison with the INTUAURA Reference 2019, the other IEMS that have a cable with a DAC/AMP. In fact, the Reference 2019 have a DSP that alters the original sound of the IEMS and fixes it to the Reference H2019. For their part, the ST2 Pro have a DSP DAC/AMP cable. The first difference is that both claim to be based on the H2019 curve. Who is closer to the H2019 curve? Judge for yourselves.



My real comparison will be against the KBEAR Robin, an IEMS that are somewhat cheaper than the final price of the Hidizs ST2 Pro set (estimated at $89). Both have a similar capsule, more classic and semi-custom in the Robin. As usual, KBEAR includes a zippered case and two sets of earplugs, though the cable is pretty basic. The Hidizs cable, excluding the DAC/AMP, has a better finish. However, Hidizs only includes a set of tips and a faux-leather pouch.
From an ergonomic standpoint, there should be many similarities, but I find the Robin's fit better and tighter.
As a dongle to play the KBEAR Robin I used the Hidizs SD2.
The Robins have a V profile with a W tendency. They have more sub-bass enhancement and a double peak in the upper mids and first treble.
The similarity in bass is high, as can be seen in the frequency response of both IEMS. The difference lies in the greater presence of sub-bass in the Robins. The bass is large and voluminous in both models. They both have that slightly slower bass style with a longer recovery. It seems darker in the Hidizs, but has more impact and punch in the Robins.
The midrange is also very similar, with a similar transition from bass to midrange, as well as the same valley. Although the Hidizs are a bit darker, I find the male vocals crisper and better defined on the ST2 Pros. The upper mids have more overall energy in the Hidizs, despite that 2 kHz peak in the Robins. This is noticeable in that the ST2 Pro model is subtly more sibilant. However, female vocals seem to have a bit more prominence in the Robins, while there is a sense of overall darkness in the Hidizs, although you could also call it softness.
In the upper range, the highs of the Robins are somewhat softer and less bright. In contrast, I find the treble of the Hidizs to be more natural, distinct, bright, crisp, and realistic. They also have better extension, air and sparkle.
The Robins have a bit more definition, especially in the midrange, with a bit more clarity. The Hidizs are smoother, warmer and more mellow. The greater sense of depth and closer mids make the Robin's soundstage seem a bit larger.



Conclusion

I think Hidizs has joined the new trend of USB DSP cables with integrated DAC/AMP. As smartphones move away from supplying 3.5mm audio output, this new set will become more relevant, especially if the integrated DAC/AMP is as adequate as the ES9281AC PRO. The cable includes microphone and a control button, so it is all-in-one and can be used with any mobile device. The cable can be purchased individually with 2-pin 0.78mm or MMCX interface and is compatible with any IEM on the market that incorporates these connection interfaces.
In this review, the cable is accompanied by IEMS with a V-profile. These are very lightweight capsules, with a dual dynamic driver with a 10mm PU+PEEK composite diaphragm. Their sound is characterized by punchy bass, warm and smooth mids, and bright and energetic highs. The starting price has been set at $39, and on the second pass it will be $49. For that price, the set is excellent.



Sources Used During the Analysis

• PC Windows 10.
• Hidizs AP80 PRO-X Red Copper LE

Purchase Link



You can read the full review in Spanish here

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Disclaimer:

• I don’t read FR graphs. I only use my ears, as earphones should be used.
• Hidizs sent this unit to me in an exchange for an honest, independent review. Rest assured that this review will do its best to devoid from any bias/es as much as possible.
• The following remarks and observations shall be made and owned only by me.
• No monetary compensation is/was involved before, during, and after the period of creation of this review.
• Your mileage may (and always, will) vary.

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Burn-in time: 4-8 hours per day, 5 days.

Source/s used:

• - Non-HiFi smartphone (Infinix Note 12 G96), PC.
• - Tanchjim Space DAC
• - Fosi Audio SK02 USB DAC
• - Kiwi Ears Allegro Mini DAC
• - Aiwa XP-V710C CD Player (12 sec. EASS)
• - Sony Xperia X Compact
• - Local Files via Foobar, YouTube Music, Deezer, and Qobuz with UAPP.

IEM/Earbud/Setup configuration: Stock medium eartips, any form of EQ or MSEB off, 12-20% volume.

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Sound signature:

• The Hidisz ST2 Pro Nebula follows the Hidizs house sound wherein it presents itself in a fun, v-shaped sound signature.

Lows:

• For an EDC setup, I can comfortably say that the bass of the ST2 Pro Nebula will entice, and probably will be enjoyable for bassheads. The bass is elevated, slightly subbass dominant, but does not leave the midbass lacking. Attack and decay leans slightly to the faster side of the spectrum, creating a “clean” yet bassy impression.

Mids:

• As for the mids, it is a bit recessed to my liking, but it is expected since this is a v-shaped sounding set. Despite this recession, I never found the mids to be too drowning or muffled in any of my test tracks and setups. Lower mids exhibit a bit of warmth, making the lower mids a bit thicker than usual. Upper mids are elevated, bright, clear, and exhibits a good amount of air, but not as bright when compared to its treble. Mild peaks and sibilance are also present in this set on certain sibilant prone tracks, such as Adele’s “Chasing Pavements” and Travis Scott’s “Sicko Mode” as some of the examples. Don’t get me wrong, this won’t be an issue or a concern for most people, but definitely something to take note and be wary of if your ears are extra sensitive to brighter upper frequencies.

Treble:

• As for the treble, it is slightly bright, well-extended, and has a bit of mild sibilance as well, just like its upper mids. Detail retrieval is slightly above average, and can render microdetails fairly easily.

Soundstage, Imaging and Separation:

• When it comes to the technical performance, there is nothing to write home about for this IEM, but that doesn’t mean that it is bad or underwhelming, it’s just that for its asking price, it isn’t uncommon. The soundstage is your usual wider than deep, with a good amount of height. Separation and layering is average at best, with mild hiccups on heavy passages. Imaging is accurate enough and does not have any problems with any of the games and podcasts I have tested this with.

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Other IEM Comparisons!

Celest IgniteX Beast

• When compared, the Celest IgniteX Beast is a more balanced, slightly warmer set. Upper frequencies on the Celest IgniteX Beast are also less bright and more safer when compared to the ST2 Nebula. The bass on the IgniteX Beast are also “softer” in character and slightly lacks detail when compared to the ST2 Pro Nebula. The rest are more or less the same.

Kefine Klean

• The Kefine Klean is a leans to a more mature, balanced, slight warm-v sound signature when compared to the ST2 Pro Nebula. It is noticeably thicker as well. Bass is also firmer and a bit more punchy. Mids is a bit more open on the Kefine Klean when compared, but is also thicker when compared to the ST2 Pro Nebula. Treble is a bit more extended on the Nebula, but both sets have nearly the same detail retrieval. Both sets on technical performance are also nearly the same in quality when it comes to the technical department, as the Klean slightly has “cleaner” separation and layering.

Simgot EW200

• The Simgot EW200 when compared to the ST2 Pro Nebula is brighter, wider, and lesser in bass IEM. Its technicalities are also better when compared to the ST2 Pro Nebula.

Rose Technics Star City 5 Pro

• The Rose Technics Star City 5 Pro is a balanced, well-controlled, safer in treble, and thicker in sound, when compared to the Hidizs ST2 Pro Nebula. Technicalities, particularly on the separation and layering, are better on the Star City 5 Pro.

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Pros:

• An all-rounder, modern everyday carry IEM!
• Versatile, v-shaped sound signature!
• Firm, punchy bassy response!
• Slightly thick mids!
• Sparkly, well-extended upper frequencies!
• Above-average technical performance for its price!
• Excellent fit, comfort, and isolation!
• Built-in DAC while having the ability to replace cables makes things easier and practical!
• Worry-free drivability!

Cons:

• Mild sibilance is present on certain sibilant prone tracks.
• IEM build quality is on the “cheaper” side, price-wise.
• Barebone accessories.

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Verdict

• The Hidizs ST2 Pro Nebula offers convenience and practicality in today’s world of nearly zero phones with 3.5mm port. I personally enjoyed this setup with my phone during commutes and running down my errands because I did not have to bring my dongle with me, keeping my everyday carry as simple as it can be. Not to mention that this also exhibits a very versatile sound character that will suit most genres and instances. Very practical indeed, Hidizs!

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Pairing recommendations:

• Source: The Hidizs ST2 Pro Nebula has its own USB DAC built in, so you shouldn’t worry about this.
• Eartips: The eartips included pairs well with this IEM, but you may still use your preferred eartips.
• Cable: The cable is sleeved, which I am personally not a fan of, but it is well-made for its price. You may still use your preferred cable since it is detachable, but you may also lose the DSP feature that the stock cable has.

Thank you for reading!

Non-affiliated link here: https://www.hidizs.net/products/hid...mance-dac-usb-c-hifi-digital-in-ear-earphones

Additional Photos Here:

Introduction​

HIDIZS ST2 Nebula is the latest addition to the HIDIZS line-up that comes with a DSP, which they are calling “The Next Generation DSP”. The DSP cable features a proper and good DAC Chip that is a much-welcomed addition in the market. Moreover, it features a curve that is closer to the 2019 Harman Curve with a slight boost to the mid-bass and is a bit airier, which gives the listener a much more engaged listening experience.

Disclaimer​

HIDIZS sent over the ST2 Nebula to our friends at Sonic Mantra for it to be reviewed. Thank you, Sonic Mantra and Hidizs for granting me an opportunity to try out the ST2 Nebula. However, my review is based on what I felt while using the ST2 & was in no way influenced by the team nor Hidizs.

The ST2 Nebula can be directly purchased from the Hidizs website, or you can pre-order from Geek Mart if you are from Bangladesh.

Also, do check out their Kickstarter page as well!

Testing Gear​

• NiceHCK TC3
• JM45
• Next Gen DSP

Specifications​

• Customized 10 mm Dual Magnetic Circuit Dynamic Driver
• Frequency response: 20Hz-40kHz
• Pin type: 0.78 2pin/MMCX
• Sensitivity: 108dB
• Impedance: 32 Ω

Inside The Package​

• The Drivers
• DSP Cable
• Three Pairs of ear tips
• USB A to Type C Adapter
• Carrying Pouch
• Paperworks

Build & Design​

The body of ST2 is built relatively good and feels durable. It is made from resin, making it a lightweight IEM. The faceplate has a metal-plating that has the Hidizs logo and name engraved. Nonetheless, it feels great to the touch.

Fit & Comfort​

The ST2 snuggles right in your ears without any hiccups. It is comfortable and lightweight to use. However, tip rolling is recommended. I used two ear tips while testing it. First is Dunu Candy and second is ePro Propeller 01. I will share what I felt after using both ear tips in my review.

Next Generation DSP​

The Next Generation DSP is an awesome DSP cable that features a proper DAC chip. I have tested various other IEMs with DSP cables, but this one is special. HIDIZS Next Gen DSP cable can be used on any IEM, and it will without fail drive them properly. I believe there is no other DSP cable in the market that can properly drive other IEMs except for its own stock drivers. The Next Gen DSP cable truly lives up to its name and is in another league compared to any other DSP IEMs in the market.

Hidizs Next Generation DSP cable has an ES9281AC PRO chip, which is capable of native DSD playback from DSD64 to DSD128, alongside 8x MQA Decoding and can play PCM up to 32bit/384kHz. Moreover, this cable delivers up to 70mW of power and has a tuning close to the 2019 Harman Curve.

Sound​

Before heading into the specifics, let me add a few things here. As stated previously, the tuning is based on a curve that is closer to the 2019 Harman Curve. From the frequency chart, we can notice a slight boost on the mid-bass section and is airier, while leaning towards a V-shape sound signature. The Sound testing was done with and without the DSP cable, with portable DACs. Below are the testing results while using the DSP Cable.

Sub-Bass​

The sub-bass of the ST2 with ePro Propeller 01(PR01) tips leaves much to be desired. Even though there is an emphasis on the sub-bass, it does not match up to the expectations. There is adequate rumble, presence and depth, but the sub-bass is clean and textured.

The sub-bass of the ST2 with Dunu Candy tips has minimal presence than with the ePro PR01. But the depth is enhanced, and it remains clean & textured.

Mid-Bass​

The mid-bass of ST2 with ePro PR01 tips are hard-hitting and clean. The performance of the mid-bass will attract the mid-bass lovers and general listeners. Fortunately, the mids-bass does not bleed into the lower Mids.

The mid-bass of Candy tips are not as hard-hitting as the PR01 but is clean, thick, and energetic. Nonetheless, it is still enjoyable and a bit more engaging than the ePro Propeller 01 tips for me. In some songs, the mid-bass bleeds into the midrange ever so slightly.

​

Mid-Range​

There isn’t anything noteworthy, apart from the fact that the mids are not overshadowed by the lows and highs. Moreover, the vocals are recessed due to the mild V-shaped curve; with the ePro PR01 tips.

The mid-range completely changes with the Candy tips! It became affluent and a bit rich, and still it was not overshadowed by the lows and highs.

Male Vocals​

Male vocals on the ST2 Nebula are quite laid-back, but are smooth and textured. It does not have any harshness but sometimes makes my listening experience dull at times as it is more laid-back than I prefer; with the ePro PR01 tips. Also, it had better separation

On the other hand, the vocals took a huge turn with the Candy tips! It became less laid-back, more textured, smoother and focused. However, it was a bit recessed and had lesser separation. Nonetheless, I enjoyed it even more than I did with the ePro PR01.

​

Female Vocals​

Female vocal lacks clarity, lacks liveliness, is harsh at times, but at least it is smooth with the ePro PR01.

Again, the vocals gained clarity and is livelier on the Candy tips. Moreover, it lowers the harshness than with the PR01 tips. It does make the female artists tracks even more engaging and forward. Regardless, the Candy tips made a huge change to the vocals than the ePro PR01 tips.

Instruments​

The instruments are fortunately forward and lively enough. However, many listeners might not enjoy it as it is not forward, or lively as other listeners might want it to be. Another thing, the instruments are not harsh; with the ePro PR01 tips.

The instruments were a tad bit livelier with the Candy tips; the rest was the same. I enjoyed it.

Treble​

The treble with the ePro PR01 is bright, airy, energetic and incredible extension, which is engaging for the listeners. Moreover, the cymbals and hi-hats are crisp, while still not being sibilant or harsh, which is a plus point for treble-sensitive listeners.

With the Dunu Candy tips, the treble remains similar, but it loses a bit of crispiness on the cymbals and hi-hats.

Soundstage & Imaging​

The soundstage on ST2 Nebula with the ePro tips is nothing extraordinary. The soundstage adds a tad bit of sense of space. It mostly lacks the width and vividness of spaciousness. However, the imaging is precise, which makes it easy to appropriately know the instruments or vocals placement.

The soundstage does not increase, nor attain, any enhancement with the Dunu Candy tips.

Non-DSP Cable Sound ​

To me, the ST2 Nebula did not sound as fun as it did with the DSP cable. Apart from the sparkly and bright sound, alongside the newly introduced sibilance which was prominent in every song. I believe ST2 Nebula performs the best with the DSP cable and I will recommend the listeners to use the DSP cable with it.

Conclusion​

The HIDIZS ST2 Pro is an incredible IEM with insane value. It is a very convenient IEM that is just plug and play. You do not need to carry an additional portable DAC with a good chip that can provide you native DSD playback, MQA 8x decoding and PCM up to 32bit/384kHz. Their Next Generation DSP cable provides them all in a form that is already present in the market. I have yet to see a DSP cable that can outperform this DSP cable in such a way. Moreover, you can fine tune this however you want to use EQ as it is a DSP cable. Additionally, the cable is cross-compatible with every device that has a type C port; an adapter can be used as well if you lack a type C part on your device.

Finally, the ST2 IEM is a must-have for a listener who loves a clean and hard-hitting mid-bass, laid-back vocals and a crispy but smooth treble. It also is not sibilant or harsh in any point. And the microphone that the DSP cable comes with is incredibly good. It is able to cut down on the background noise and only capture the speaker's voice extremely precisely and clearly.

If you purchase the ST2 Nebula IEM, you will get the Next Generation DSP cable which is universal and works with any IEM; you are also getting the IEMs itself, which is a great choice if you want incredible mid-bass and an extravagant treble that is bright, but not sibilant. Moreover, the vocals are good, even though it is a bit recessed.

Tip Rolling​

Tip rolling is essential for every IEM, especially this. The stock tips do not do the IEM justice. The ePro Propeller 01 makes the sound a bit analytical, while the DUNU Candy makes the sound fun and engaging.