Sennheiser HD6XX: Though very functional, the predominately plastic HD6XX isn’t as premium in its build and design as the Alpha. It’s a comfortable headphone in its own right, though I prefer the wider headband and deeper pads on the Alpha that provide a little more comfort despite the headphone’s additional weight. The HD6XX has very shallow pads by comparison though its lower clamp force creates a comfortable if less stable fit.
The Alpha is similarly balanced overall, but is a little less linear than the HD6XX; slightly more engaging through its bass and midrange, and smoother in its high-frequency presentation. Overall, it can be characterised as a more neutrally toned and cleaner headphone with a greater focus on transparency over timbre. I did the following testing with the Alpha’s stock pleather pads, take into account that they can be made brighter using the included hybrid pads.
Though bass is similarly present on both, the Alpha extends a little further, delivering greater sub-bass impact. Its mid-bass is also a little cleaner, with a more neutral tone where the HD6XX is warmer. Both are well defined, the HD6XX has larger notes as it has more mid-bass while the Alpha is more physical with deeper focus and greater separation. The Alpha is more defined with greater speed.
The HD6XX is more full-bodied in its midrange voicing, delivering natural, if slightly thicker vocals. On the contrary, the Alpha is less elevated through its upper bass and lower-midrange, creating a more neutrally toned, transparent midrange. Male vocals are more forward than the HD6XX though female vocals and higher instruments sound more laid-back on the Alpha if similarly clear.
The Alpha is smoother up top, most notably with regards to lower-treble. It has a bump in its middle treble for added air and clarity but has a smoother foreground detail presentation. On the contrary, the HD6XX has a slightly more pronounced lower/middle treble that makes it more aggressive and more articulate. Both are well detailed, the Sennheiser brings intricacies more to the fore while the Alpha is more linear but also more laid-back.
The HD6XX has a similarly sized stage to the Alpha, but it sounds more separated due to its brighter midrange and lower-treble. The Alpha lacks the same separation but can achieve grand expansion when called for. Imaging is excellent on both, though the more agile, extended and linear Alpha is more accurate and holographic.
Finally, the Alpha extends further in both directions, delivering higher resolution as a result. Despite the HD6XX being nicely balanced and natural, its presentation lacks the layering of the Alpha, its individual notes are also less wholly resolved despite being more articulated on account of its brighter treble and upper-midrange.
Excitement is dangerous, especially for a reviewer; a heavily influencing false expectation that skews opinion towards polarising extremes. The Alpha was definitely a headphone that intrigued me, especially given my affinity for their lower priced designs. On the other hand, I was apprehensive about Advance Sound’s ability to weave a coherent signature using in-house parts, especially given their limited experience with planar drivers. Luckily, unlike many things, the Alpha lived up to a lot of my expectations and presumably others given the predominately positive impressions I’ve seen online.
For a first attempt, their construction impresses, besting industry staples and upholding comfort during longer listening. And when properly driven, the Alpha thrives. They don’t awe on first listen, but build a gradual appreciation over hours of critical listening; and those searching for balance will find it in the Alpha’s mature and well-integrated tuning. The level of quality on offer also greatly impresses, with a stable presentation and surgical control. Its bright middle treble and skewed male vocals will not suit some. But if you’re searching for a well-balanced open-back headphone, newcomer Advanced Sound have produced one of the most versatile offerings yet.
The Alpha can be purchased from Advanced Sound for $499 USD. I am not affiliated with Advanced Sound and receive no earnings from purchases through this link.