It's been well over a decade since I started reviewing audio gear. As you can imagine, I've ended up on the mailing lists of quite a few audio companies and PR firms since then. I get solicited for reviews on a regular basis but unfortunately only have time to accept a very small fraction of the offers. This means the item in question must be fairly compelling - maybe a new product from a well-established firm, or an item that has lots of buzz on the forums, or perhaps a new technology that I find interesting... something to stand out from the many other options available.
The item under review today falls into the latter category. Some months back I was contacted by a company called AME Custom, based out of South Korea. AME is a relatively new firm who at the moment offers just a handful of models, in your choice of universal or custom designs. My regular readers know that I vastly prefer customs due to standard IEMs generally fitting my ears poorly. As such I've got tons of experience with CIEMs but am not usually all that up to date on the latest/greatest universal options. So AME agreed to send me a custom molded set of their Radioso ($1350) for review.
Radioso is what AME terms a "Tribrid" design. That means a triple-hybrid using three different types of transducer technology, arranged to leverage their strengths within the sonic spectrum. We get a dynamic driver specifically handling low frequencies, a balanced armature for midrange, and a quartet of electrostatic drivers dedicated to the highs, with signals routed by a 3-way crossover. Again, these are the stereotypical areas where each type of driver generally performs best, so the design seems to make a lot of sense. Note that the dynamic driver gets a small vent, placed just below the cable socket and protected by a filter to avoid any debris entering the shell. Unlike some other vented CIEMs I own, this does not significantly impact isolation.
There are several other tribrid options out there using some variation of this same theme, including the Noble Khan, Jomo Trinity, Vision Ears Elysium, and probably some others I'm forgetting. They all use different arrangements in terms of driver count and configuration, not to mention crossover tuning etc, which means they should all sound unique despite the presence of all three types of drivers. Worth noting is the price difference involved - those models all live in the $2,500 to $3,000 neighborhood, whilst AME sells their tribrid for less than half that price. Note that a universal version is available for $1200, while the custom option is $1350.
AME offers another model called Argent which is a totally different 6-driver design using dual electrostatic highs and quad BA drivers with a 4-way crossover. It is priced identically to Radioso, so I guess we could say co-flagship status. It may have launched just a bit prior to Radioso, and there are a few good reviews to be found here. As far as I can tell, AME seems to have positioned Argent as semi-neutral. Their words are "immersive, well-rounded sound featuring warm lows and sparkling vocals". Meanwhile Radioso is described as having "rich low-end response while fully highlighting the unique characteristics of the electrostatic tweeters". I have not heard Argent so I won't comment any further as far as comparisons go.
There are some (non-sonic) compromises apparent when looking at the Radioso compared to the more established tribrid competitors. Where those models offer numerous customization options and extravagant aesthetic packages (some included in the base price, others for an extra fee), AME limits Radioso buyers to fully clear or clear with wooden face plates. They mention "custom artwork" available for a $300 upcharge, though I'm not certain what that entails. Regardless I don't think AME is trying to compete when it comes to fancy builds. Don't take me the wrong way though - my (completely clear) review pair seems built to a very high standard, and pics of the wooden face plate option look very attractive too. The Argent model has abalone pearl instead of the wood option and that also looks to be quite well done. So it's a matter of simplicity and limited options rather than poor quality. Still, for less than half the price, I don't feel this is unreasonable, and my experience is that newer CIEM companies tend to branch out with more options as they become more established.
As far as packaging - the box is a simple and functional affair which showcases the IEMs as soon as you open it. Included is a metal storage case similar to that used by a few other brands, along with the typical cleaning tool and 1/4" adapter. Universal versions ship with a few tip choices, and both models get a leather cable organizer with "AME" logo which I don't find particularly useful. It's not the most comprehensive bundle I've ever seen but it gets the job done well enough.
The AME site mentions their "6N OCC Pure Copper Silver Plated Cable" with the classic 2-pin style connection. The one I received appears different from what I see listed on the product page or reviews of the Argent model. The pics show a quality thin silver cable with nice chrome-looking Y-splitter and angled plug, but mine appears more like the classic cables used by Westone and Ultimate Ears back in the early CIEM days, complete with plastic molded bits. It does the job well enough but feels somewhat delicate - I'm glad most IEM brands use a more beefy cable these days. Granted, back in the early Westone/Ultimate Ears days these cables proved very reliable, so who knows. I did most of my listening with a bespoke Effect Audio pure silver cable anyway, so I can't speak of any compromise involved in the stock cable nor the specific cable I happened to receive.
After a quick test to confirm proper fit, I left the Radioso to burn in for well over 100 hours. That's usually the goal I shoot for, as a sort of "just in case", but this time I got tied up and couldn't get back to it as planned... so it probably got more like 200 hours total. I did not monitor to see what (if any) changes took place during that time.
My initial listening, as far as portable devices, was with a Samsung Galaxy S10. I then upgraded to an LG G8 thinQ, followed by a side-grade to the diminutive Shanling M0, and finally the Cayin N5iiS. I don't currently have any higher-end DAPs on hand, as I'm generally not much of an on-the-go listener at this point in life.
So I brought out the big home system - Equi=Core 1800 balanced power conditioner, Nativ Vita music server streaming via Roon from an Asustor NAS in the other room, McIntosh MCD600 spinning CD/SACD titles as well as acting as DAC for the Nativ via SPDIF connection, and Pass Labs HPA-1 amplifier, with Audio Art cabling all around except for the previously mentioned Effect Audio IEM cable. This rig is resolving and powerful enough to bring out the best in any headphone, yet utterly silent even with the most sensitive IEMs.
My first impression came straight from a Samsung Galaxy S10, playing Qobuz lossless files. Right off the bat I could tell two things about the Radioso: first, that it had a beautiful, dynamic, and very slightly U-shaped signature with superb extension on both ends. Second, it really needed a better source to shine. I found myself cranking the volume to nearly the maximum levels on the S10, and I'm not usually a high-volume listener by any means. The bass had great impact but clearly ran out of steam down low, and staging was essentially flat. Inexperienced listeners might stop right there and dub Radioso merely a decent IEM, but I took these issues as signs pointing to the need for a better player.
Switching to the LG G8 thinQ (still playing Qobuz) which has the same DAC implementation as their audiophile-approved V-series, I proved my theory correct - Radioso performance was excellent. It still had that mild U-shaped tuning overall, but really opened up the presentation in all dimensions, and the frequency extremes both started filling out. I played through most of Avishai Cohen's Seven Seas, then a few tracks from Philharmonics by Agnes Obel, and finished up with a mixture of Carpenter Brut, Moose Blood, and classic hip-hop supergroup Def Squad - just to see how Radioso deals with a wide range of genres.
Through it all I heard the same superb clarity in the upper mids and highs, controlled yet weighty midrange, and rather generous low-end impact. At this stage I would call it a somewhat bassy signature though not overdone in most situations. Midrange was just a touch set back in the mix with respect to lows and highs, though not enough to feel recessed or lacking - in fact mids were very articulate and thick enough to be satisfying with all sorts of material. And those electrostatic highs? Despite there being a quartet of drivers handling the upper frequencies (compared to just one driver each for lows and mids) the presentation did not feel overly bright, sharp, or aggressive. While detail was plentiful, and clearly more extended than most (or all?) of my other CIEMs, it felt very smooth and natural. I could listen for hours or use higher-than-normal volume levels and not experience any treble fatigue, which is not a common occurrence for an IEM that isn't dark or rolled-off up top.
Complaints? I felt the bass was just a touch overbearing at times with the G8, particularly with more subdued music like Agnes Obel or the slower tracks from Avishai Cohen. While prodigious extension is always welcome, I could have used a bit less midbass from time to time. And again I still had a suspicion that I wasn't properly driving the Radioso to the fullest potential - I was still cranking the volume significantly higher than usual to get the desired outcome.
Switching again to the Shanling M0 brought out a different set of strengths and weaknesses. This time the lows were more controlled and midbass did not intrude where it wasn't welcome. Midrange was rich and bold, and the upper midrange had excellent energy. Unfortunately the highs now seemed a bit more vivid than I would find ideal. Not a problem at all with many tracks, but at times I found it a tad overwhelming. What may start as being dynamic and fun ends up being fatiguing as time goes by - trumpets have too much bite, certain vocals become crispy, and cymbals in particular have too much energy. Some people are more sensitive than others to the issue, but for me it makes for one of the few times I would actually prefer the LG G8 to the Shanling M0.
Moving upscale to the Cayin N5Sii solved this problem. Now everything worked in harmony to provide a big, bold take on the mild U-shaped signature, without any of the previously mentioned shortcomings. Bass was tactile, weighty, yet very well controlled. It had a sense of impact and definition that only a superbly design IEM can provide - it's as if I could feel the air pressure moving as I would when listening via speakers. Midrange texture was beautiful, with gobs of detail and rich tonality. Highs were ethereal and airy, with seemingly limitless extension. The presentation was open and spacious on a level only a handful of top-tier IEMs could hope to match. In short, this was among the very best I've ever heard from an IEM at any price. Which is impressive considering it "only" sells for $1350. That statement may sound absurd but remember that top CIEMs these days go for at least double that.
The Cayin N5Sii, while excellent for the price, is certainly not in the conversation for best sound available from a portable device. So I switched to my desktop rig to finally get a sense of how high the Radioso can scale. What I heard ended up raising the bar for what I thought possible in an IEM.
The McIntosh/Pass Labs rig takes everything I loved about the Radioso and turns it up a few notches. The level of realism is just astounding. Any questions I had about coherency with the tribrid setup went out the window once I heard Radioso in what I consider its final form. Interestingly, the low end actually feels a touch more subdued here, as do those stunning highs. Or maybe I need to think of it from another angle and say the midrange becomes more forward and full. Whatever the case, the U-shaped signature is not as immediately noticeable in this scenario (though it never quite becomes a ruler flat signature, which I'm actually thankful for).
But talk about dynamic - this thing shakes the foundations, giving some of the hardest hitting, most convincing bass I've heard this side of a huge subwoofer. I mentioned it before but I'll reiterate - at times it really does feel like some air is being pressurized, in a way that even my favorite armature-based IEMs just can't match. And that treble? Zero grain, totally liquid and flowing, with decay and sustain and beautiful tone that just sounds like real life. The top end air reminds me of my big Stax rig - a very rare achievement for IEMs. Can you tell I love the Radioso sound on this system?
Two other things worth mentioning. First, the sense of space surrounding the music is palpable. Not only is the soundstage wide and deep, but also very precise. Usually when an IEM has a presentation this "out of head", it comes somewhat at the expense of accuracy. Sort of a 3-dimensional blob. Which is still impressive, until you try and focus on any single instrument only to find you can't really place it all that well. Either that, or the signature is just thin and lacking tonal density, which always seems to improve focus in the imaging/soundstage department (think mini-monitors in the speaker world). Radioso manages to fill out that note thickness while achieving both spacious and accurate staging.
The other aspect to point out is the fact that while these can play very loud and clean (on the right system), I actually find myself listening at lower and lower levels when I'm not critically evaluating. I take that as a good sign - I'm not trying to compensate for any perceived lack of detail or impact.
After spending time with Radioso, switching back to CIEMs that I otherwise enjoy is just a disappointment. The UE Reference Remastered sounds comparatively dark, lifeless, and slow. Empire Ears Zeus XR sounds bloated. Jomo Audio 6R sounds thin and nasally. Even the mighty 64 Audio A18t - probably my favorite CIEM overall - can seem a bit dull and uninvolving compared to the Radioso, though it does make a good comparison of sorts. If we start with the general A18t signature, crank up the bass texture and impact, then mix in the insane treble clarity of the Unique Melody Maven, we might end up with something similar to the Radioso signature. But don't forget to slash the price by more than 50 percent. Am I saying I actually prefer the Radioso sound to the A18t, regardless of price? Perhaps. I need more time to directly compare them, but at this stage I'm leaning in that direction.
I really wish I had a half dozen more DAPs here in the $500-3000 range, just to see if any of them could approach this level of performance. Obviously my big setup (approaching $20k or so) will likely still have an advantage over even the best portable players, but I suspect some of the best DAPs out there may come close enough. Whether using a portable or home system, you'll really want the best possible chain to get the most out of the Radioso.
A comparison can be made to the venerable Sennheiser HD650. Not really in terms of sound signature, but rather the fact that both models can scale ridiculously well. They are both make sound yet seem fairly underwhelming straight from a phone. Yet both respond incredibly well as your system improves. And at some point they both start outperforming more expensive flagships when paired with a really nice setup. While the Sennheisers respond more to amplification, I'd say Radioso is equally picky when it comes to DAC and even transport quality, so make sure all of those are on point to really hear them at their best.
I've had about a dozen requests to review CIEMs over the past year or so, and have declined them all. I didn't find a single CIEM I felt worthy of writing about in 2019. Not that I think the industry was stagnant during that time, but I felt the generally incremental sonic improvements just didn't warrant my attention. To put it another way - nothing I heard in 2019 felt like a significant jump over models I reviewed the year prior. Now it's 2020 and the AME Radioso feels important enough to grab my attention.
It may seem weird for me to rave about this $1350 CIEM as if it were some sort of uber flagship release. But honestly the pricing is just another thing AME got right with this design - it's actually kind of a sad sign of the times when most people dismiss sub-$2k releases as something less than state-of-the-art. I've heard most of the competing tribrid designs and while they all sounded enjoyable in their own ways, none really stood out to me like the Radioso does.
I admit that the mild U-shape is one of my favorite signatures, which no doubt impacts the level of enthusiasm I have for this CIEM. But I'd say it has a fairly universal appeal rather than being more of a specialty sound like the UM Maven, and I think most listeners would really enjoy it. The beautiful tuning combined with superb technical abilities add up to a very compelling product which I can easily recommend - just make sure your playback chain is up to the task.