Pros: Quality sound, excellent build, hybrid design, great price
Cons: reduction in upper midrange clarity, needs a better L/R indicator
When it comes to headphones, I'm often in pursuit of the best sound or the best value. With in-ear headphones, typically the choice is either a dynamic driver (bigger size, warmer sound, harder to cover the whole dynamic range, cheaper) or balanced armature driver (smaller size, brighter sound, allowing multiple drivers in the same headphone housing, more expensive). This pretty much defines the trade off between better sound control and better value. Lately, there has been a new trend with in-ear headphones, a hybrid design using a single dynamic driver tuned for low frequencies and a single or multiple BA drivers for mids and highs. Today I'm going to take a look into one of these unique hybrid in-ear headphones manufactured by Astrotec with a single dynamic and a single BA driver. Here is what I found.
My review unit came directly from Astrotec, and I assume all the included accessories is exactly how it's being sold new from retailers. I always start with a look at the packaging, and these arrived in a small compact box with English/Chinese text, including a note about legal disclaimers and a list of specifications including a taped-over correction for headphone impedance which is listed as 12 ohm (in original on-line listing it was 8 ohm). After opening the box, you are greeted with AX35 which has a very professional (audiophile quality) solid metal body polished look with a multi-color twisted cable inside of the clear silicone soft shielding (flexible and relativity tangle free) with a metal y-splitter followed by a metal sliding cable cinch. 3.5mm connector is gold plated with a same metal body, very slim so it can be used with any smartphone in a case even with a smallest headphone opening. Looking further in the box, you find a round tin can storage box, very different from typical draw-string bags or hard shell cases with a zipper. This really makes a statement of being unique, although I would recommend using a regular hard shell case down the road because you don't want metal earpieces to be banging against metal walls of this storage can, but it does make a great storage for accessories. And speaking of accessories, included are a total of 3 pairs of S/M/L silicon eartips (a better quality than a typical generic stuff), a pair of medium foam tips with a resemblance to Comply, and a pair of soft silicone earhoops to assist you in wearing headphones with a wire over your ear.
Beside a solid build, headphone body has a unique shape with elongated nozzle design to use different eartips and allowing a deeper insertion in your ear. I personally use the biggest eartip size with all of my in-ear headphones, and due to a soft nature of the included tips, for my testing I was using hybrid tips (very appropriate for hybrid headphones ) I borrowed from my v-moda faders. Looking closer at the design, you will find an opening pinhole port on the back (typically to widen the soundstage) and the opening pinhole port at the base of the nozzle (typically for bass control). The strain relief is minimal and should work, though I really wish they would color code it like in E10 with red on the Right side. Unfortunately, the only way to distinguish the R/L is by looking up a small white letter marking on the body of the headphones next to strain relief - if that is a paint and if it will wear off after a while, there is no other way to separate left and right. I hope this is taken into consideration with any future revisions.
Now, we come to the most exciting part - the sound test. Knowing a typical sound characteristics of dynamic driver and single and multi driver BA headphones I reviewed in the past, I was very curious to find out how AX35 is going to sound. From the spec listing of 12Hz-23kHz frequency response (in comparison to a typical 20-20k), I was already expecting a greater bass and some extension in highs. My sound analysis was done driving AX35 from X5 DAP, Galaxy Note 2 (directly and connected to E18 DAC), as well as my laptop using variety of FLAC and 320kbps mp3s. In general I found the sound to be consistent, and these are easy to drive from any source. So how would I describe it? I would definitely file it under fun v-shaped sound signature with an enhanced bass, slightly recessed mids, overall sound being warm and detailed, and also a wide dip somewhere around 5k-6k (guessing based on reduction of vocal clarity and some Innerfidely charts of similar sounding headphones). The bass in AX35 is truly amazing thanks to the dedicated tuning of 10mm dynamic driver. With other single dynamic driver in-ear headphones, it seems that you have to "stretch" your sound tuning across the entire dynamic range. Here the driver tuning is isolated, and the bass goes deep down to sub-bass textured layer with a fast punching mid-bass, very full and detailed without feeling bloated. Treble has plenty of details as well, and has a pleasant sparkle without high frequency fatigue, definitely appreciated for an extended listening period.
Ok, so what about mids (intentionally leaving it to describe last)? They are detailed, no question about it, and also they do feel slightly recessed which could be also as part of a perception next to the enhanced bass quantity. I have a number of BA in-ears, and quite familiar with a bright sound signature of these, especially when it comes to upper mids and vocals. With AX35, it seems to have an attenuation down in a region of frequencies somewhere around 5k-6k which is easy to hear with vocals due to a slight loss in clarity. Don't get me wrong, vocals are present and detailed and have a very smooth warm signature, but clarity is not well defined. I put over 20hr of burn-in, hoping it will change, but it was still the same. As a matter of fact, I just read Joker's (THL) first impression of AX35, and he also mentioned a sound being v-shaped and being slightly veiled in midrange. I don't want people to take it in a negative way, since these are great v-shaped headphones with a fun signature, and anybody who's listening to EDM, pop/rock, and rap/hip-hop will absolutely love it!!! But those who are into classical or jazz or just like more emphasis on vocal details - these will not be for you. Furthermore, I also want to add these have an amazing soundstage, way beyond a lot of other in-ear headphones in this price category or anything even double the price. Also, with a right selection of eartips, you will get a decent passive noise isolation. In addition, I was very pleased there was hardly any microphonics effect with wires worn down or over the ears.
Overall, though I probably spend a little too much time focusing on sound shortcoming - these are probably among some of the best v-shaped fun headphones I heard in a long time!!! As a matter of fact, during my sound test in addition to switching between other in-ear dynamic and BA pairs, I was also comparing them to my V-Moda M-100 and I found AX35 bass presentation to be much better, as well as better definition of midrange. Astrotec went for a specific sound signature, trying to accomplish it with a single dynamic driver and a single BA driver - and they nailed it with flying colors!!! What makes it truly amazing, these sell for about $75 which is a fantastic value!!! Considering a solid build and top quality of materials, excellent sound presentation with an amazing bass quality/quantity while not necessary being a basshead headphones, and a very affordable price for a hybrid design without cutting any corners (headphones specific, accessories aside) - these make a great addition to anybody headphone collection, no matter if you are a casual listener or a seasoned audiophile!
Here are the detailed pictures of AX35.