Tonality & Presentation
The Alpha, for the most part, delivers a fairly linear and neutral to natural tonality that I find quite engaging. From 20Hz up to around 1k, you will not see too many bumps and dips in its response.
Beyond that point the Alpha does has some coloration with a slightly elevated vocal presence followed by a more subdued upper midrange. The treble response is fairly energetic also with some sparkling presence around 5-7k. It also has more than decent headroom and plenty of sparkle with that little hifi bump post 10k.
It is that coloration post 1k that may affect your listening preference and it does depend on what you feed it signal-wise to some extent. Pull back on heavy percussive tracks, particularly hi-hat and cymbal work and the Alpha is a very engaging and nicely detailed planar experience.
Push too hard on the lower treble and you get a more dominant odd harmonic infusion that delivers a slightly glassier overtone. This can distract a bit more from the Alpha’s otherwise excellent performance but I must emphasize this is not a generally bright signature.
I do find that a better amp signal or certainly a signal with better output power will allow the Alpha to scale and control a bit better than your regular DAP experience. This does add weight to my feeling the Alpha will shine with a solid desktop amp or one of those current mode portable amp beauties from the likes of Bakoon.
Staging wise the Alpha has good depth, a reasonable level of width with a perceptible level of headroom and air. The midrange bump does push vocals a little further forward so it is not a vast canvass but it is not overly intimate either. I do like the imaging on the Alpha though. It is not as vague as some of the older generation double-sided planar variants with a very good level of spatial cue awareness.
I have it slightly different from Advanced’s own smoothed out chart on their website. There it seems to tail off a little from 150Hz down to 20Hz but I never felt the Alpha lacked extension or sub-bass presence. In fact, the Alpha can be surprisingly deep sounding delivering an excellent distortion-free and fairly powerful low-end signature. It won’t slam like an overly abused dynamic driver but it has a purer tone to it that works particularly well with EDM and rock.
The mid-bass has a slither of warmth that reaches up to 500Hz but the elevation is not more than 1-2dB and reasonably nuanced in its effect. You get a smooth attack and decent body, particularly in lower-pitched instrumental timbre which sounds very natural to my ears.
From 500Hz to 1k the Alpha retains a fairly linear and balanced signature drawing a little low-end warmth and sitting slightly behind its elevated 1-2k bump.
There is a tiny dip just before the bump which pushes some instrumental work behind vocal presence a little depending on the vocal pitch. Higher pitched vocals will sound a little fuller and further forward as it arcs over that 1-2k range. Lower pitched male vocals will fall back a bit more but might display a bit more warmth as a result.
Instrumental timbre is nicely balanced for my tastes and reasonably accurate sounding. The rhythm and bass guitar harmonic balance are excellent with zero sharp overtones and a smooth but clear attack.
If there is an uneven area it is the treble response of the Alpha if underpowered. First, this is not a rolled-off or dark sounding treble region. It has some excellent headroom and plenty of air with energy right up into the final octave and beyond 10k.
There is, however, a fairly pronounced elevation around the 7-8k marker. I presume this is tuned for a perceivable level of clarity and detail. If you do not push the Alpha too hard it works with a nice level of sparkle and air.
However, push it too hard with some rapid percussion attacks you get from the likes of power metal or airy synth-wave passages and it can dominate the presentation a little more. Some will find the net effect to be a brighter harder attack and an odd harmonic imbalance, especially with cymbal and hi-hat work.
A few things you can do with the treble response is to change pads and get a great amp to pair it with. Hybrid pads will tend to give it a little more top-end prominence though by not a huge degree. The protein pleather pads bring in a better balance for my tastes and soften the treble response a bit more. The better the amp in terms of power and quality the smoother the treble response of the Alpha.
The Alpha is rated at 34Ω and 90dB SPL. Whilst it is easier to drive than the older generation of Hifiman planar headphones such as the HE6 or HE500 it does sound optimal with a decent amount of power running through it.
Which is why I am puzzled by the 3.5mm terminated cable. Sure you can stick it in a nice DAP such as Sony’s W1Z or the Questyle QP2R and you will get either a warmer signature and reasonable power. However, I would find a quarter jack or some other longer cable with dual 3.5mm TRS plugs and stick this in a quality amp because it performs so much better with about 2-2W of power balanced or unbalanced.
Xi Audio’s Formula S solid-state flagship amp is what I had in mind when I mentioned how things can change in the Alpha’s treble response with a good signal. This is going to deliver a little over 2W into 32Ω which is more than enough for the Alpha to drive with authority. Most importantly the response was tight with excellent control of the upper treble response. If you want to hear smooth then plug it into this amp. You will be hard-pressed to hear anything glassy or bright with this combo.
This isn’t just a one-off amp pairing success. The excellent Violectric V281 combined with an ES9038Q2M infused Project Audio Pre Box S2 Digital as the feeding DAC sounded brilliant. Once again, that top-end never got out of control. Perhaps a little cooler sounding than the Formula S but I never felt it become too harsh and certainly better than most portable sources.
The Alpha’s like good power and I heartily encourage you to apply it before coming to a possibly hurried judgment.
With DAPs, I was pushing up the volume on high-gain and all the while the Alpha felt a little more compressed and darker sounding in the mids than it needed to be. If you must use DAPs I would go with a warmer sound or something a bit meatier and avoid neutral or underpowered DAPs.
Switching to a current mode portable amp such as the Bakoon HPA-01M injected a far better level of dynamic range in the Alpha’s performance. Current mode amps work well with planar headphones. Particularly so with the mids which sounded more resolving and articulated. The treble did sound a little more strident than the smoother bigger desktop pairings but never felt out of control.
Ok, so its $499 SRP but in reality, the price of the HE400i has been all over the place in the last year and as I check sits at just $219 on Amazon which is a bit of a bargain.
Build quality on the HE-400i is ok for me and on par with the Alpha. The Alpha maybe feels the more robust of the two and is heavier by around 55g. The Alpha does clamp a little harder though so depending on your level of tolerance to clamping it will either feel more secure or more fatiguing on the head compared to the HE400i.
The HE400i is rated at 35Ω and 93dB and on paper it has a marginally better efficiency level than the Alpha but truth be told their loudness levels were almost the same on the desktop amps we tested it on. Both excel on desktop amps rather than portable sources.
Tonally both of these are in the same ballpark with a neutral to natural response and a slight hue of mid-bass warmth. They go a bit more for musicality than outright accuracy.
There are however two discernable differences with the Alpha having a bit more sub-bass weight and presence than the HE400i and a bit more treble forwardness. The HE400i rolls off a bit earlier than the Alpha and is not as linear up to 1k.
Mids on the HE400i are a bit more neutral around 1-2k compared to the elevated response of the Alpha so vocals are good on the HE400i but not as forward at times as the Alpha. It does have more 2-4k energy than the Alpha so some female vocals can sound “bigger” depending on the pitch and percussion has a bit more elevation.
Treble on the HE400i is not as extended, forward or airy sounding as the Alpha. the Alpha treble is a bit more dominant on lower-powered sources but nicely controlled on powered desktop amps. The difference between the two comes down to the amount of energy in the final octave and the Alpha has more of it.
The EL8 is a larger and heavier open-back planar magnetic design. It uses Fazor technology, weighs in at 520g, and to my eye at least looks quite striking with its blend of wood veneer, half gimbal and of course the lightning connector system.
It is rated at 30Ω and 102dB and a fair bit more efficient than the Alpha so it can and will get louder faster on a weaker source. That is not to say it doesn’t scale, it just doesn’t scale as much as the Alpha can with a desktop power amp.
Also, the stock cable on the EL8 is a bit meh and slightly veiled in comparison to some great aftermarket cables. I tend to run this with a DHC silver Litz variant that really does wonders for the EL8 dynamic range, clarity and also lifts that slight veil in the EL8 presentation. Swapping the stock Alpha cable for the Hifiman Edition X V2 cable also delivers a nice lift in clarity and treble control so both do benefit from better cables.
The EL8 is quite a bit more mid-centric than the Alpha. Whilst the Alpha may have a somewhat forward 1-2k bump the entire focus of the EL8 sort of rises and falls on the 1k marker. You get significantly more roll-off below 100Hz also with the Alpha sounding much more linear and balanced by comparison.
On the flip side, the EL8 has a lot of warmth infused into the lower mids with a rising response from 10Hz up to around 1k. The instrumental timbre is a little thicker and heavier hitting than the Alpha in the lower-mids. The Alpha’s 1-2k bump is not replicated with the EL8, instead, it dips markedly from 1-4k throwing a little bit of a veil on the vocal and presence region compared to the Alpha which is more open sounding and spacious over the same range.
Like the Alpha, the El8 picks up a little bit of mid-to-upper treble energy and has some sparkle in the final octave but I do not the presentation to have as much air overall. In fact, the El8 delivers a far narrower staging quality than the Alpha.
MrSpeakers AEON Flow
The AEON Flow is MrSpeakers’ latest mid-fi planar project which we reviewed a few weeks ago and rated it very highly indeed. It is a lighter open-back planar with a modernistic design, half gimbal structure, and super light Nitinol headband design.
Compared to the Alpha it is 115g lighter but with smaller planar drivers. The cups are taller and less conventional-looking than the Alpha’s traditional round cups but also clear the ears nicely making for a very comfortable fit.
Like the Alpha, the AEON Flow will sound ok with weaker sources but does scale nicely with better amps. It is rated at just 13Ω and 95dB so my preference, like the Alpha, is paired with some higher-powered amps such as the Violectric V281. The Bakoon HPa-01m is also an excellent pairing with the AEON Flow if you do need something more transportable but always with a mind of about 1W output into 32Ω as a good starting point.
The AEON Flow has a bit of a warmer and more relaxed signature than the Alpha. Its low-end has more of an elevated yet smooth mid-bass bump and less sub-bass presence compared to the Alpha which stays relatively linear right down to sub 30Hz.
Like the Alpha, it has an upper treble emphasis with a bit of sparkle around 8k and you will hear it due to the rather dipper nature of the AEONs curve around 3-4k. The accompanying tuning pads of the AEON Flow will dampen that down somewhat but I prefer them off. The sparkle is good, even on weaker sources whereas the Alpha will sound glassier in its top-end when underpowered.
The gentle drop from 100Hz and that dip at 3-4k of the AEON will throw a little veil over its vocal and presence region and more of a dominant lower midrange dominance. The Alphas 1-2k hump will accentuate vocals that bit more and bring them further forward than the AEON.
AEON Flow throws a much smaller soundstage than the Alpha with less depth and width. However, it is slightly more refined than the Alpha, particularly in instrumental timbre. It is also the more forgiving of the two for longer listening sessions.
The Advanced Alpha was and is a welcome surprise to the planar magnetic headphone market. It is a very good performer with a solid desktop system delivering a linear but well extended low-end with a good body and a clean and clear midrange with some vocal elevation. The treble does need some good power to tame but once you find the right match it competes very well indeed with similarly priced or mid-fi competitors.
The secret to this headphone is not to rush it or come to a fast conclusion. That 3.5mm terminated cable is a red herring designed to make you think it will pair with something mobile. It won’t. It will give you loudness to some degree but it will lose a bit of control especially in its treble performance. You need good power to drive it properly.
Outside of that, it is a solid build, utilitarian but attractive in its own right and it sits well enough on my head with more than average clamping power. The packaging is attractive and to be honest, it looks the business for $499.
Alpha Technical Specifications
- Driver type Single-sided n48 planar magnetic
- Size 96mm
- Driver diaphragm Silicone composite
- SPL 90dB+/-3dB (1kHz/1mW)
- Impedance 34ohm
- Frequency response 20Hz – 40kHz
- Maximum input power 20mW
- Rated input power 50mW
- Cable composition Silver-plated copper
- Cable length / type 1.5m / detachable 2.5mm jack
- Output connector type 3.5mm gold plated