I/O Audio Sogno 2DD+6BA

IO Audio is an emerging brand that made a significant impact with the introduction of the Volare. This flagship model, while remaining affordable, has received acclaim from both critics and enthusiasts alike. The Volare is very well made, offering a comfortable fit and outstanding sound quality that exceeds expectations for its price range.

IO Audio Sogno

IO Audio has returned with their second installment, the Sogno, which is a hybrid in-ear monitor priced at $200 less than the Volare.



Technical highlights

The IO Audio Sogno features eight drivers on each side, in contrast to the Volare, which has nine. Specifically, it comprises two dynamic drivers and six balanced armature drivers, all integrated through a five-way electronic crossover and a four-way physical crossover.

The Sogno includes a proprietary coaxial dual dynamic driver system, which consists of one 10mm and one 6mm driver. The 10mm driver, with a silica gel suspension and a mixed paper dome, is responsible for managing bass and a portion of the vocal range, while the 6mm treble driver is engineered to enhance the impedance characteristics of high frequencies.

Furthermore, four specially designed balanced armature drivers provide a consistent timbre in the high-frequency range, while an additional two customized balanced armature drivers are dedicated to improving the upper high frequencies. The sensitivity of the system has also been fine-tuned to minimize the requirement for extra frequency crossover components, thereby optimizing the overall system design.

You can read more about the IO Sogno here.



Non Audio stuff

The IO Audio Sogno features a design and exterior similar to that of the Volare, albeit with a distinct faceplate pattern. While the Volare's faceplate is reminiscent of a thorny bush, the Sogno's design evokes the image of bare tree branches.

The entirely black ear-shells are embellished with silver metallic spots that appear to float within the material. Each shell is marked with the letters "I" and "O" on the left and right sides, respectively, while the back of each shell displays the "SOGNO" logo in gold lettering.

In my previous review of the Volare, I noted that it is among the most aesthetically pleasing and distinctive in-ear monitors ever created; however, I believe the Sogno surpasses it in beauty and could easily be a contender for a design award.

The ear-shells are crafted from a medical-grade resin compound in collaboration with the esteemed Heygears. The quality of the 3D printing is impeccable, resulting in the Sogno being exceptionally well-constructed and smoothly finished, with no visible imperfections or flaws in the molding.



Wearing comfort

The ear-shells feature an ergonomic design that resembles a custom fit, complemented by a gently extending sound tube. Despite the number of drivers, they are lightweight and compact, ensuring an excellent fit.

The ear-shells extend slightly beyond the ears, yet they provide a remarkably comfortable experience, effectively isolating sound. They can be worn for extended periods without inducing any discomfort.

The cable

The IO Audio Sogno features a high-quality cable akin to that of the Volare, with the primary distinction being that the Sogno's cable consists of four strands of cross-braided 6N OFC oxygen-free copper silver-plated wire, as opposed to the eight strands found in the Volare.

This cable is modular and utilizes a 2-pin interface, with the package including 4.4mm, 3.5mm, and 2.5mm plugs. It shares a common issue with the Volare’s cable, as it may become lodged in the stem of the modular plug.

Overall, this cable is well-constructed and lighter than that of the Volare. It offers considerable flexibility, resists tangling, and produces minimal microphonic noise; however, the splitter is somewhat heavy, which can cause the cable to sag.



Accessories

The Sogno is presented in a more understated box compared to the Volare; however, it is equally well-equipped despite the variance in price.

Included in the package is a premium carrying case that resembles a jewelry box, along with a dedicated cable storage bag, a cleaning cloth, and five distinct types of ear-tips, each available in three sizes.

Each set of ear-tips is neatly organized in its own small plastic container, resulting in a total of five containers. It is important to remember to remove the two foam inserts from within the carrying case to create sufficient space for the earphones and your preferred USB DAC dongle.



About the ear-tips

The package comprises five sets of IO branded ear-tips, designated as TW45, TW40, TW43, ST50, and F49. All ear-tips are made of silicone, with the exception of the F49, which is memory foam. The collection features a combination of medium and wide bore ear-tips, with the ST50 being the narrowest and the TW40 the widest.

Upon testing all sets of ear-tips, I found them to be equally comfortable; however, their performance varied significantly in terms of overall frequency response, particularly regarding bass extension.

The TW40 was the only set that delivered satisfactory performance with solid bass extension, consistent with the published measurements. In contrast, the other sets produced a bass-light and thin sound, with the Sogno notably lacking in sub-bass and bass presence.

Additionally, I explored the Penon Audio Liquor and Divinus Velvet wide bore ear-tips. The Liquor provided improved sub-bass extension and a more balanced frequency response compared to the stock tips, while the Velvet ear-tips outperformed all others by a considerable margin, offering robust sub-bass, neutrally toned and full-bodied lows, balanced mids, and a treble that was not overly bright.

It appears that the IO Audio Sogno is quite sensitive to ear-tip selection, necessitating experimentation with both the stock and various aftermarket ear-tips to achieve the desired tonal balance. It is important to note that the IO Audio Sogno is capable of excellent sub-bass extension and full-bodied bass; if this is not perceived, the issue likely lies with the ear-tips being utilized.

My listening observations pertain specifically to the IO Audio TW40 and the Divinus Velvet wide bore ear-tips.



Sensitivity

The IO Audio Sogno has 12.8Ω impedance with 126.5dB/Vrms of sensitivity so it is ridiculously easy to drive. However there is a catch, the source must be dead silent with an output impedance as low as 1.5Ω (or ideally lower) and a wide margin of volume adjustment so it doesn't get loud too fast. For this review I have used the iBasso DX180, FiiO M23 and Cayin N6iii DAPs.



Audio stuff

Direct comparison notes with the IO Audio Volare are provided in the subsequent text.

The IO Audio Sogno can be regarded as a more Hi-Fi oriented iteration of the Volare that follows closely the Harman target curve. For the Sogno, IO Audio has chosen a tuning that is more balanced and tonally precise, featuring a slightly reduced bass emphasis, a marginally more pronounced treble, and a similar midrange recession as observed in the Volare. In this context, the Sogno may still be classified as a mildly “V” shaped earphone, albeit to a lesser degree than the Volare, while maintaining a satisfactory mid-range presence.

The sub-bass is strong and impactful, yet it is not overly accentuated to the point of overshadowing other frequencies. The bass exhibits a more natural and accurate tuning compared to the Volare. While the low-end does not achieve a strictly neutral reference, it demonstrates improved tonal accuracy relative to the Volare.

The bass response is meticulously calibrated to suit both discerning and casual listening scenarios. The Sogno demonstrates improved fidelity in reproducing the low-frequency instruments of a symphony orchestra, while also delivering an exhilarating and enjoyable experience with contemporary bass tracks.

The dynamic driver utilized in the Sogno exhibits a more technical performance compared to that of the Volare, resulting in a bass that is both tight and well-controlled, featuring precise timing and excellent layering. The bass quality of the Sogno is notably cleaner and more defined than one might anticipate for its category, yet it remains surprisingly robust and elastic. This driver is capable of displacing a significant amount of air, producing a punchy and impactful bass response, with rapid recovery that allows it to seamlessly adjust to a broad spectrum of sudden dynamic shifts and tempo changes.

The mid-range frequencies are notably accentuated in the upper mid-section, resulting in a vibrant and dynamic sound where certain overtones are highlighted more than others. This characteristic may cause listener fatigue with specific recordings or sources, particularly for those with heightened sensitivity in this frequency range. However, in most instances, especially with classical compositions, the mid-range is rendered with tonal accuracy and a natural, organic quality, albeit with slight hints of artificiality in the higher harmonics.

The sound presentation is both realistic and lifelike, featuring rich yet clearly defined textures. The music flows naturally, creating an unobstructed auditory experience. The Sogno delivers a melodic and expressive performance, offering considerable excitement for electronic music and emotional depth for classical pieces. Overall, its performance is comparable to that of the more expensive Volare.

The treble and upper high frequencies exhibit a notable distinction between the Sogno and the Volare, both in terms of quantity and quality. The Sogno presents a more vibrant and radiant sound compared to the Volare, yet it does not reach a level that would render it harsh or piercing. While it is undoubtedly brighter and more effervescent than the Volare, it maintains a commendable degree of control and smoothness.

In terms of speed and clarity, the Sogno outperforms the Volare to a slight extent. Initially, it may seem to offer superior detail retrieval; however, it soon becomes apparent that the Volare excels in this aspect. The electrostatic drivers utilized in the Volare provide a smoother and less grainy sound, along with enhanced resolution and refinement, surpassing the balanced armature drivers found in the Sogno.



The Sogno, however, offers a more illuminating experience in its musical presentation, sounding notably fresher and more invigorating than its counterpart. The timbre predominantly exhibits a natural quality, though subtle hints of metallic brightness can be detected, while the texture maintains a consistent weight in the lower frequencies.

In terms of soundstage, the Sogno distinctly surpasses both the Volare and many competitors. Its expansive and airy quality evokes the sensation of using a full-sized, open-back headphone. The soundstage is broad without appearing artificially enhanced, featuring precise imaging and separation, along with impressively satisfying depth layering. It is grand and immersive enough to accommodate a wide range of large-scale music, making it equally suitable for movie watching and gaming.



Conclusion

The IO Audio Sogno, while more affordable than the highly praised Volare, does not fall short in terms of performance. It features a more neutral-balanced tuning complemented by outstanding technical capabilities, making it suitable for both discerning and casual listeners without significant drawbacks. This earphone serves as a versatile option that pairs effectively with a variety of sources and delivers pleasing sound across diverse musical genres.

In addition to its impressive audio quality, the Sogno is exceptionally crafted and offers remarkable comfort. Its striking design is complemented by one of the finest accessory packages available in the market.

Following a strong introduction with the Volare, IO Audio's second offering is equally remarkable. The IO Audio Sogno emerges as a highly competitive and solid choice in a crowded marketplace, making it easy to recommend.

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The review sample was kindly provided free of charge in exchange for an honest review. I don't use affiliate links. The price of the IO Sogno is $399 and you can buy it from Shenzhen Audio.

Disclaimer: For various Google indexing reasons, most parts of this review have been processed with an automatic paragraph rewriting tool. However it reads exactly the same as the original content that is available in my website.

This article first appeared on my private blog here: klauseulenbach.de
Consider reading my introduction as a disclaimer: About Me
Note: I purchased the IO Audio Sogno at full price without discount.



I had teased and mentioned the IO AUDIO (I\O Audio) Sogno in my SIAS impressions. On that day, I think it had the best-tuned upper mids and transition into treble that I have heard in a very long time. So I went ahead and purchased a pair from Shenzhen Audio to share my impressions with you in more detail. Before I deep-dive into the sound description with details and measurements, I share the unboxing and early impressions.




The Sogno is packaged very nicely in a medium-sized box. The IEMs are separated from the cable and presented in an inlay inside the rather faux leather travel case. What immediately strikes the eye is the abundance of ear tips. There are four different sets of silicone tips and one with foam, all in a separate plastic case. 15 different ear tip pairs are probably enough to find a good fit. However, every ear tip only has 3 sizes (S/M/L), and I struggle to get a seal with most of them. It seems I need something between M and L. Ultimately, I would prefer fewer different types of ear tips but more granular sizes.



The ear shells are made of 3D printed resin and the shell has an ergonomic shape. In terms of comfort, it’s very average, which is good considering how comfortable IEMs have become. The faceplate is unique, though. Under the flat resin surface lies a 3D structure resembling something between a tree and a thunderstorm. The black-and-white colour scheme makes it look eerie and mysterious.



The specifications claim the use of high-purity (6N) SP-OFC strands for the cable. The 4 strands are not tightly woven and look a bit loose, yet the sheathing is not free of memory. Sogno‘s cable is not stiff, but also nothing special. I do like the option to unscrew the termination and swap it for a total choice of three options, though I don’t think a balanced 2.5mm is needed anymore. It’s not a „quick switch“ – like from DUNU – but it’s easier to change than replacing the whole cable.



Interim summary: The IEMs are well-built, beautiful to look at and decently comfortable. They come in a nice package and have good accessories. IO Audio prepared everything to floor you… so how is the sound?

Upon first listen, I was absolutely amazed. I experienced a very natural-neutral-sounding reproduction. I was floored at the show in Shenzhen! Secretly, I was already celebrating a new entry to my recommendation list.



Now that I have spent more time with the IO Audio Sogno, I still have to commend it overall. The Sogno is a fantastic recommendation for users with a Harman-neutral preference. It features a sloped bass curve that really picks up below 200 Hz and makes sure all the sub-bass an IEM can reproduce is transferred to your eardrum. Yet the bass quantity is never pushing itself to the front. This is not a bassy IEM! It’s also not warm.

The midrange has a slightly cold nature to my ears. Your perception may be different depending on your expectation of neutral. Compared to my reference, the Softears RS10, the Sogno has 1-2 dB more presence across the whole upper mids. That is hardly a big difference, yet noticeable and just enough to ascribe a cold signature to it. While you still get bass punch and impact, the mids lack a tiny bit of weight and body to sound fully natural to me. The treble is in line with the upper mids. In fact, the transition from upper mids into low highs and beyond is fantastic and among the best I have heard. The treble contains all the details but has no sharpness or sibilance at all. Here is the measured frequency response:



In terms of soundstage, the bass tilt creates decent depth yet voices are very upfront. Since vocals lack a bit of fullness, the Sogno sounds less intimate yet at the same time also closer to the listener. It’s a very close-spaced soundstage reproduction that still preserves depth information. The treble does help to make the Sogno sound very open, but less so in terms of imaging.



Without the luxury of being able to compare with the RS10, S8 or RSV, the I\O Sogno could be a reference for neutral tuning. To my ears, it’s just barely bright, which also makes it sound open. Depending on the ear tips, I was fooled into thinking the ear tips didn’t seal well. But this complaint is based on comparing with the best I ever heard and the Sogno is the cheapest of the bunch. At $ 399 I can easily recommend it and also consider it to be one of the best in its class. But if you like a warm and lush sound, and especially want to avoid any form of shout, this is probably not the right choice for you. Any treblehead should order immediately!

General/Packaging/Build/Comfort
I/O Audio, a relatively new entrant in the audiophile market, has quickly made a name for itself with its second debut model, the Sogno. Priced at $399, this 2DD+6BA configuration demonstrates the brand's commitment to delivering high-quality audio at an attractive price point. The Sogno arrives in a luxurious package that befits its flagship status. The IEMs are housed in a premium faux leather case, while accessories like the cable and ear tips are neatly organised.The included cable, a high-purity OFC SPC with interchangeable plugs (2.5, 3.5, and 4.4mm), adds to the premium experience. In terms of comfort, the Sogno's shell is neither too big or small based on my experience, it will probably suit everyone, the secure fit and excellent seal make it comfortable for extended listening sessions. The inclusion of multiple ear tip options, including wide bore, narrow bore, and foam, ensures a personalised fit for most users.
The Sogno's design is both elegant and functional, with a smooth finish and a visually appealing faceplate. The overall build quality is exceptional, reflecting I/O Audio's dedication to crafting premium products.




Gears used for this review

• DITA Navigator
• Fiio KA15
• I/O Audio Sogno Stock Cable and Eartips
• Fiio M23
• Letshuoer EJ07M Stock Cable and Eartips

Foreword
My review is solely based on what I hear via my equipment and I never consider my reviews to be objective in any way rather a subjective approach. Do take into consideration that everyone’s ear anatomy is not the same, so the psychoacoustics perception might be different as well, but i believe it will not stray too far

Sound
The Sogno's tonality leans towards a neutral-warm character, offering a balanced sound signature that avoids any harsh or overly bright elements. Despite featuring six balanced armatures, the IEM's timbre is remarkably natural and free from any noticeable BA coloration. While there might be a subtle hint of BA timbre detectable upon close inspection, it's largely imperceptible during casual listening. The tuning of the Sogno is slightly U-shaped, emphasising the sub-bass frequencies for a more impactful and engaging listening experience. The mid-bass region is also well-represented, providing a satisfying foundation for various musical genres.

Bass

• The sub bass is rumbly and has good extension, but i wouldn’t say it is anywhere near basshead kind of rumble, it does rumble when the track calls for it
• Mid bass has good body and it doesn’t sound thin, double bass pedal doesn’t sound bloated or lacking in terms of texture, Slipknot’s People = crap, during the fast drumming, every hit can be heard clearly
• Bass from the Sogno is tight and clean transition between the sub and mid bass is quite balanced without sounding incoherent
• I personally find the tuning of bass is done right to my preference,somewhere between fun and audiophile but not venturing into the basshead category, but i do yearn for a little bit more in terms of bass quantity

Mids

• The mid range has plenty of details and they don’t sound recessed at all
• Vocal doesn’t sound recessed nor too forward, just right to my ears
• Male vocal in my opinion sounds quite full and well textured, possibly due to the implementation of dual DD and also the warmer sound signature, female vocal on the other hand also has very good energy level to it, even when you crank the volume higher, it doesn’t sound “shouty”
• The upper mids are generally quite safe sounding, but again, it depends on your tolerance and sensitivity, and most importantly, the fit

Treble

• Now, the treble, is also another strong point of the Sogno, it has plenty of energy and air, yet it is not harsh sounding
• It is smooth overall with no hints of sibilant even when you crank the volume up
• Detail retrieval is very good and actually for the asking price, i personally think that it is punching above its price point

Soundstage/Imaging

• The Sogno’s soundstage is not that “big” sounding, a good width and height perception, separation is also top class
• Imaging is very good,the instruments can be pinpointed easily in busy track like Slipknot’s Duality
• The technicalities of Sogno is very good overall

Driveability

• The Sogno is not hard to drive and it does sound decently loud even from weaker source like Apple’s Lightning Dongle, what i want to stress is that, sounding loud is not equivalent to driving power
• My observation is that it doesn’t really benefit much from power, just slight changes in terms of sound from the various source that i have test, possibly due to it having fairly low impedance and high sensitivity

Comparison (Letshuoer’s EJ07M)

• Switching over to the EJ07M for the purpose of comparison,i would say the tonality between the EJ07M and Sogno is vastly different
• Priced at 669$ for the EJ07M vs Sogno at 400$, in terms of value, Sogno definitely have a lot to offer at the asking price
• The tonality of the EJ07M is leaning towards warmish and deeper sub bass extension/rumble compared to Sogno
• In terms of bass, the sub bass does have a bit more quantity and extends quite deep compared to Sogno, but the mid bass is slightly less punchy compared to the Sogno
• Mids are fairly clean sounding, the male vocal especially, can be a little thin at times, female vocal however is very sweet and full of energy
• Treble is quite smooth with plenty of details due to the inclusion of EST drivers, it is quite airy and contributed to a big soundstage
• Technicalities i would say the EJ07M performs at probably around 20-30% better than the Sogno, which is to be expected since it is costing more, but given the asking price of Sogno, i personally think Sogno is very impressive
• Shell size, the Sogno is slightly larger than the EJ07M

Final Thoughts
Having tested the Sogno for several weeks. It is safe to say that it offers a very good and high price performance ratio. For a mid ranger, it does almost everything right, of course there are some cons if I were to nitpick. The Sogno has been my daily driver since i received them, i have even put it up for comparison with some of the more expensive models from Letshuoer, and the Sogno definitely isn’t too far from and costs way less. This is definitely an outstanding release from I/O and I am definitely looking forward to their upcoming releases. It deserves a 5 out of 5 stars, another 5 stars from me for I/O Audio. Highly recommended!

*The Sogno is sent over by ShenzhenAudio for the purpose of this review. I thank them for the support and opportunity as always



Head over to the official store if you are interested in getting one, it is currently being priced at 399$

I/O Audio Sogno - Non affiliated Link