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.
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Unboxing & First Impressions
Packaging and Accessories
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.
Build & Comfort
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.
Cable
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?
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.
Lows
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.
Mids & Highs
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:
Soundstage
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.
Verdict
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!
