Hybrid designs are common today, and many include DD and BA drivers. A6 is a tri-hybrid design with 1x 10mm DLC (diamond-like carbon coating) dynamic driver, 2x midrange BAs, 2x treble BAs, and 1x Piezo Electric ceramic high frequency tweeter, in total of 6 drivers. This particular PE tweeter is designed using 7 parallel ceramic layers. I don’t know the exact layout of the drivers inside but do see a front venting pinhole on the inside of the shell, toward the nozzle, perhaps where the DD driver is located. Also, when filter nozzle is removed, I can see 2 exposed BA drivers and no visible tubes, but don’t want to make any assumptions at this point.
The shell of A6 is all metal, with a solid durable build, and contour surface on the inner side for a custom-like fit with concha area of the ear. There is a recessed 2pin socket, designed for standard 0.78mm pins, though some of the other cables I tried had a tight fit. Tolerance of 2pin connectors and sockets is an ongoing issue with many IEMs and aftermarket cables.
While the shell and the metal faceplate are all anodized black, the edges of the faceplate have an aluminum shiny bevel which makes it look more unique. Faceplate is flat, has company name in small letters, and LOUD button with a nice tactile response when you push it. I assume they called it “LOUD” since it functions like a gain switch, but in reality, it’s an impedance switch where being off sets the nominal impedance to 45 ohm (and sensitivity of 110 dB) and turning on changes it to 20 ohms (and sensitivity of 115 dB). I will talk more about the effect of this switch in the follow up Sound Analysis section.
The nozzle of A6 is replaceable and you can choose from 9 filters, all color coded, and split into 3 groups, A/B/C. These filters affect only 3-7kHz region of the sound, and each group’s triplet either has a baseline (0dB) or +/-3dB boost or cut. Also, each filter group has a different opening diameter, A being the widest and C being the narrowest, and it has some kind of an earwax screen guard. Looking through I can see the light, thus no damping filter inside, only the variation of inner shape of the nozzle.
Group A (frequency response 10Hz-40kHz)
- Blue: 3-7kHz, +3dB
- Black: 3-7kHz, 0dB
- Red: 3-7kHz, -3dB
Group B (frequency response 15Hz-30kHz)
- Gold: 3-7kHz, +3dB
- Dark gray: 3-7kHz, 0dB
- Pink: 3-7kHz, -3dB
Group C (frequency response 20Hz-20kHz)
- Dark Blue: 3-7kHz, +3dB
- Sliver: 3-7kHz, 0dB
- Purple: 3-7kHz, -3dB
I found the fit to be very comfortable. With a right selection of eartips you get a good isolation, though in my case a tighter fit often means some driver flex, which I found to be present here. That’s my personal trade off I have to deal with since I have a large earcanal opening and usually require the larger size eartips.
I analyzed A6 sound performance using LGPT as my source while playing a variety of my favorite test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Robin Schultz “Oh child”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”. As recommended by manufacturer, I let A6 burn in for 100hrs.
To start off, I found 3-7k filter to be very effective. If you consider 0dB as a baseline, going up +3dB has a noticeable boost in mids/vocals, maybe not exactly 3dB but close to it, to the point where w/LOUD off it changes the signature to being more mid-forward. With LOUD on, the boost gives vocals a better balance with a bass, changing signature to more w-shaped. Going down -3dB also has a very noticeable change where I hear the attenuation to be more than 3dB, dropping the mids/vocals and turning the signature into a more v-shaped sound, even more noticeable when LOUD switch is on. Also, -3dB drop brings more bass to the sound sig.
When switching between groups A/B/C, I hear a noticeable change between A and B/C where A has the widest soundstage expansion with the most aggressive lower treble. B/C soundstage is wide but not as holographically expanded as A, and still with a noticeable out of your head depth expansion. Though B/C have a little less air, their treble control is better. The change between B and C is subtler, a touch wider soundstage expansion in B and a little attenuated lower treble in C. All comes down to micro-tuning of the sound.
LOUD on/off affects the nominal impedance and sensitivity of A6 which affects the bass and the mids by shifting their level up with LOUD on (20 ohm impedance) versus shifting it down with LOUD off (45 ohm impedance). The piezo-electric ceramic driver sound level is not affected by LOUD control, but you get the side-effect of treble change as a result of shift in lows and mids.
Soundstage is wide and holographic, with an excellent imaging of the sound. Piezo driver also adds a lot of air between the layers of the sound, contributing with impressive separation of instruments and vocals. The technical performance of A6 punches way above its price tag, but I also think that PE driver is a secret sauce here.
With LOUD off, bass is more neutral and more balanced, but turning the LOUD on gives it a linear boost across sub-bass and mid-bass without overwhelming the signature. This boost gives the bass a more textured, more analog, more layered, articulate quality.
Regardless of the selected filter or LOUD impedance control switch, mids are maintaining a lean body, below neutral in lower mids, with more focus on upper mids, bringing forward micro-details of the sounds and vocals. If you are looking for a smoother, more natural organic tonality in vocals, A6 is not it. Instead, it has a higher level of crisp detail retrieval.
Treble is the shining star of A6 tuning. It’s very crisp, airy, big contributor of its high resolution, and has a very good extension thanks to its piezo-electric ceramic driver. At the same time, if you are sensitive to crisp revealing sound and prefer a more controlled, smoother lower treble, or if you are sensitive to sibilant peaks, you will have to spend more time going through filters and eartips. The included filters refine the mids, they don’t touch PE ceramic driver. But when you push LOUD impedance switch on and try different filters, the overall change in sound balance has the effect on the treble.
In a summary, filters here give you the ability to fine-tune the sound, and it’s more than just subtle. For me personally, I prefer a more natural balanced detailed tonality, with more treble control. So, I focused on 0dB filter and I stepped down from group A to group B and ended up with group C where I get the most non-fatigue lower treble response. Switching between +/-3dB filters gave me more room to fine-tune the signature where +3dB boost brought mids up, balancing them better with treble and bass. At the end, I picked Dark Blue filter (group C, +3dB boost) as my favorite, and also kept LOUD switch on. Also, switching to Symbio hybrid eartips was my final micro-adjustment. The only compromise of going with Group C filters is a shrinkage of soundstage width. It’s still wide, above average, but not on the same level as in Group A.