Rosson Audio Design RAD-0 - Open, Customizable, Planar Headphone - Review

Review written by Andrew Park (@Resolve)

Introduction

I was aware of the RAD-0 for some time before I got to see it and try it out, with the knowledge that this was a new headphone from Alex Rosson, one of the original minds behind Audeze. He’s now started his own headphone company called Rosson Audio Design. I had seen photos of his first headphone under this new brand, which admittedly don’t do justice to how aesthetically interesting they look in person, but beyond that I didn’t know much.

Review unit provided on loan for evaluation by headphones.com and “The HEADPHONE Community” Preview Program.

Given how I feel about Audeze’s design choices in general, I was cautiously optimistic. I’ve never liked the Audeze weight and bulk, regardless of their sonic qualities, some of which I’ve also been critical of in the past.

Because of these assumptions and the common ancestry between the RAD-0 and the current line of top Audeze headphones, I went into this review attempting to answer three questions:

1. Where does the RAD-0’s technical performance fit relative to the Audeze line-up?
2. Were they able to solve the weight and comfort issues that have consistently been a problem for Audeze?
3. Does the RAD-0 have a better tonal balance than the LCD-4, especially in the treble?

Specs

• Cable Connectors - 3.5mm
• Cable Length - 2 Meters
• Transducer Type - Planar Magnetic
• Transducer Size - 66mm
• THD - <0.1%
• Impedance - 29 Ohms
• Weight - Over 600g
• Price - $2,600

Source

FLAC Library, TIDAL (HiFi and Master) - iFi iDSD Micro Black Label -> Cayin IHA-6 -> RAD-0

Music

While I’m generally a huge jazz enthusiast, lately I’ve been getting more into heavier material from my younger days. For jazz I went with Sophie Milman, Studnitzky, Stacey Kent and my usual favorites of Holly Cole and Patricia Barber. For heavier material I’ve been enjoying Periphery a lot lately, but I do find the vocals on all of their albums to be a bit rough sounding, so it’s actually a decent test for sibilance and other consonant issues. I also sat down with Opeth’s Pale Communion and listened to the whole album in one session - truly an amazing album, and more dynamic than a lot of stuff coming out these days.

Design, Build & Comfort

The RAD-0 is simply incredible to look at, and at first contact with the ‘Graffiti’ model, it’s clear that this is one of the most interesting headphones aesthetically. Of course, I don’t generally care about how a headphone looks, but when something stands out in such a striking manner like the RAD-0 does, it’s worth mentioning. Moreover, there are a number of different visual designs to choose from when purchasing a RAD-0, each with their own unique look, and you can even customize your own on their website (although that costs a bit more at $2,999).

I was immediately able to answer one of my initial questions - whether this headphone fixes the weight and comfort issues I had with the LCD-4 and other Audeze headphones - with a hard “not really”. Unfortunately the RAD-0 is just as heavy as those other monstrous headphones, but on the plus side, it’s not as bulky. This is partially due to it using 66mm planar transducers rather than the whopping 106mm ones used in the LCD-4. Rosson Audio claims the RAD-0 uses “a proprietary array of 11 N52 magnets” - meaning high-grade Neodymium is being used - but beyond that it’s not entirely clear what’s responsible for the ‘magic’ here. The weight alone does indicate a double-sided array, and in my experience those do perform better than single-sided planars like in some of the previous generation of HiFiMAN products.

But in spite of the weight, I do find the RAD-0 to be more comfortable for long periods of listening. I’m not fond of the headband design and much prefer a strap system, or a wider piece that distributes weight along the top better, but the clamp force is also quite tight, which takes some of the pressure off the top. While it’s not that comfortable at first, I find it easier to wear for longer periods of time as the pads conform to the sides of my head. The yokes are also very satisfying to slide up and down and they’re actually angled outwards, so the further they’re extended the less the clamp force is. Overall the comfort is passable but still definitely too heavy, and while the clamp force helps with the top of my head, it’s still a bit tight for me.

Performance

Thankfully the RAD-0’s performance is excellent and the positive Audeze inheritance is obvious throughout as well. To answer another one of my initial questions of how it compares to the top Audeze headphones (specifically the LCD-4), it does extremely well.

Resolution & Detail Retrieval

Out of headphones around $2,600 that I’ve heard recently, namely the ZMF Vérité, the Meze Empyrean, and the RAD-0, the Rosson Audio headphone comes the closest to the ultra top of the line headphones like the LCD-4 or the Utopia. While to me it doesn’t quite match the LCD-4, it gets seriously close, not just for instrument separation but for lifelike and accurate reproduction of individual instrument lines as well.

Speed & Dynamics

Unsurprisingly the RAD-0 is also quite fast, likely aided by the N52 grade magnets. The speed is comparable to that of the top of the line Audeze headphones as well, however the RAD-0 doesn’t slam with quite as much intensity, perhaps due to the smaller transducer. Nonetheless it does still hit hard enough and is easily enjoyable.

Soundstage & Imaging

The RAD-0 has a decently wide stage, and it’s not without decent depth as well. In fact there’s a substantial difference between the farthest and closest points (partially due to the frequency response). Vocals in particular sit very close in front of the listener, while the rest of the instrumentation is spread out more to the sides. In that sense it’s not as ‘speaker-like’ in its presentation as the image isn’t focused towards the front, but instead more to the left and right. I don’t consider this a bad thing though. Instrument separation is also superb, and this headphone does extremely well with vocal harmonies. There’s such careful and surgical precision to how voices come across, and as mentioned, they sit very close to you - which sets them apart from the accompaniment in the rest of the mix.

Timbre

This is another win for the RAD-0. The RAD-0 takes after Audeze’s timbre qualities more than anything else, and that’s a very good thing in my opinion. That means it has a bit more sweetness and richness to the tone, rather than the occasional dryness I find in some HiFiMAN headphones.

Tonality

Raw and HEQ compensated measurements taken with the MiniDSP EARS Rig. This is not an industry standard measurement system. The bass looks a bit jagged but unless the environment is ideal for measuring open-back headphones it can be difficult to get 40hz and below accurate.

To answer the last and perhaps most important question I had coming into this review, the RAD-0 does indeed fix the tonal balance issues of the LCD-4. My problem with the Audeze flagship is that it’s overly subdued in the lower treble, and then the region above 10khz is overemphasized. This creates an effect where instruments don’t sound realistic. For example, the tonal focus and presence for a cymbal hit is recessed, but the splash quality is elevated. Incidentally, Audeze have also fixed the tonality of their flagship with the use of their ‘Reveal’ DSP, however with the RAD-0, you don’t need to use any software to get it to sound good, and more importantly for instruments to sound ‘correct’.

In spite of the linearity shown in the top graph, this is a more mid-forward headphone relative to the typical consumer curve that adds bit of a bass boost. So the fact that the RAD-0 doesn’t have that means the midrange sits a bit higher relative to those targets (as shown by the HEQ compensation). If we assume that the shape of the EARS rig’s pinna and concha aren’t substantially different from the average human ear (they very well might be) the only real issues are that the rise at 4khz doesn’t show up early enough, and the elevation doesn’t continue on long enough afterwards. This may cause it to look like a bit of a peak at 4khz on some graphs (again, HEQ), but it really doesn’t sound like that, which again makes me want to point the finger at the EARS rig.

Nonetheless, if we compare the RAD-0’s tonality to that of the LCD-4, it’s clear that the former doesn’t have the same tonal balance issues found in the latter. The RAD-0’s treble is perhaps some of the best I’ve heard. It retains a reasonable amount of air, while at the same time refusing to be sibilant, even with some of my more unforgiving tracks. It does this without reducing that range either (like a lot of other headphones do), so it’s not afraid to have enough energy in the traditionally difficult to tune area between 7-10khz, hitting the sweet spot so it doesn’t come across as harsh or grainy. Ultimately this means they’ve managed to get the tonal balance just right for properly representing instruments, and that’s something the Audeze ‘house sound’ typically hasn’t been able to do.

With that said, the two gaps on either side of the primary elevation at 4khz (before and after the rise) do tend to subdue certain elements of the mix - to the effect that it’s not my favorite headphone for classical orchestral music, which often has that wall of sound that makes good use of treble frequencies. The dips cause certain pieces of orchestral music to sound just a touch closed in - but it’s only a little bit subdued, unlike the LCD-4, which dips for way longer, and for just about every other genre, the RAD-0 does an exceptional job.

Comparisons

Audeze LCD-4

The LCD-4 is still technically very impressive, and it does win on detail retrieval capabilities and it slams a bit harder as well. This is especially noticeable in the bass, but it’s surprisingly close, and that’s very impressive for a headphone that costs quite a bit less. Moreover, the RAD-0 has better tonal balance out of the box, with exceptional treble that isn’t overly sharp or bright but still has enough presence and clarity for excellent resolution. Without EQ, I definitely prefer the RAD-0 over the LCD-4. The RAD-0 is also slightly more comfortable for long sessions.

ZMF Vérité - The Vérité is my daily driver, and it’s also a more mid-forward headphone. What I like about the Verite, I like about the RAD-0, and they’re both warm headphones that have a tonal balance that manages to properly represent instruments so that they come across in a lifelike manner. It’s a difficult comparison because the Vérité is a dynamic driver headphone and the RAD-0 is a planar magnetic, but I actually think the RAD-0 gets ever so slightly closer in terms of detail capability to the LCD-4. The Vérité wins in a few areas, namely it has a more spacious stage, is a more natural listen overall (better mids), and is much more comfortable. But I also find I prefer the treble of the RAD-0. Where the Vérité has a hint of sharpness at 8.5khz (depending on the pads), the RAD-0 is perfectly smooth.

MrSpeakers Ether 2

The Ether 2 weighs less than half of the RAD-0, and so unsurprisingly it’s much more comfortable. It’s also technically quite capable, however the RAD-0 does win in terms of strict detail capability. The Ether 2 does have a more spacious stage to the front and not just to the sides like the RAD-0, but the latter does have slightly better surgical precision imaging and ‘blackness of background’. The RAD-0 is also faster and slams harder.

Sennheiser HD800S

Beyond simply soundstage, the HD800S also does detail quite well, but the RAD-0 wins in just about all performant categories other than soundstage. This is especially noticeable in the bass, where the RAD-0 performs better by a mile. So while the HD800S may be more spacious and surgical, the RAD-0 is a lot more fun. Of course, the HD800S is also way lighter and more comfortable.

Conclusion

As much as the RAD-0 is a great looking headphone, it’s not just all about the looks. This is one of the better sounding planars out there, and it looks like Alex Rosson has been able to alleviate many of the issues I had (and likely other people have) with Audeze’s tonal balance. Moreover, the RAD-0 has extremely positive technical performance as well, especially in terms of detail retrieval and speed. It comes closer to that of the LCD-4 than just about anything I’ve yet heard at its price range. Nonetheless, my primary gripe with Audeze headphones is still my main complaint here: it’s just too heavy. Part of me worries that in making the RAD-0 truly a work of art, Rosson Audio Design has made a concession in terms of weight. Still, this is more my personal axe to grind against any headphone that weighs over 500g, and the RAD-0’s comfort is still a bit better for longer sessions. So for those who are used to the Audeze weight, the RAD-0 gets a thorough recommendation from me.

You can check out my video review here:

-  Andrew Park (@Resolve)

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