I’d like to thank Meze’s Alexandra Rizoiu for giving us early access to Astru to get properly acquainted with this beautiful IEM in the lead-up to our review. Your ongoing support is greatly appreciated.
While Romanian audio extraordinaire Meze is best known for its jaw droppingly-beautiful headphone designs, the company has long flirted with smaller form factor IEMs too.
Advar was my first experience of a Meze IEM, and true to form, it carried through the gorgeous design aesthetic, comfort, and laid-back warm sound of its headphone brethren. Alba, a more cost-effective, entry level IEM, was released not too long ago, and didn’t really pique my interest. Instead, I heard rumours that Meze was working on a new flagship IEM, and for months I waited patiently for word on the project.
Today, all can finally be revealed. Aptly called Astru – in keeping with Meze’s naming conventions – it means a celestial body in Romanian, and is very much intended to be the star of Meze’s small but substantial IEM portfolio.
Priced at a surprisingly modest $899, Astru debuted briefly at the recent CanJam New York convention, and unsurprisingly flew under the radar for most showgoers chasing the latest, biggest and most expensively-exclusive.
The few reports I did read about those who happened on the Astru demo pointed to a solid, well-balanced but otherwise unremarkable IEM, which made me think about how difficult it must be for manufacturers to stand out their products in such a noisy and competitive crowd.
Meanwhile, I’d already been using Astru for a few weeks, and was well on the way to realising that it’s probably the ‘best’ single driver IEM I’d heard to date.
That’s not giving anything away, really. It’s an IEM that’s as comfortably sounding as it is to wear, one of the very few you can actually use to sleep on your side with, with a design language that’s entirely familiar for anyone even remotely familiar with Meze.
While it may not turn that many heads nowadays (unless it comes with a multi-kilobuck price tag), Astru’s single-driver approach is very much intentional. Meze is betting that a carefully engineered dynamic driver can deliver the layering, imaging, and resolution typically associated with more complex designs without the potential coherency issues that can arise from crossovers and multiple driver types working together.
Whether that gamble pays off will depend on each individual who hears it, but the technical foundation certainly seems promising.
The minimalist aesthetic is likewise refreshing, adding to that sense of calmness and cohesion I get every time I put them in and press play. Simple done right is one of the hardest things to do well, but Antonio Meze is a master of the craft, and Astru is clearly a continuation of this legacy.
Packaging and accessories
Meze has put genuine thought into the presentation and accessories package, which is more comprehensive than many IEMs at this price point.
A silkscreened sleeve with metal foiling covers the compact clamshell cardboard box, which splits down the middle to reveal the IEMs and cable inside a pre-cut tray. It takes a bit of finger aerobics to release the cable from its enclosure, but once that’s done, all the other bits and pieces become easily accessible.
The premium balanced cable features CNC-anodised aluminium hardware, including a striking ‘wishbone’ splitter reminiscent of Meze’s headband clasps, and a gold-plated 4.4mm balanced termination.
It feels like a proper cable too, not an afterthought, with clear, smooth SoftFlex PVC sleeving that’s completely free of microphonics, and doesn’t tangle or twist when stored away. The cable wire features silver-plated Linear Crystal Oxygen-Free Copper (LC-OFC) conductors arranged in a dual-strand configuration, with 161 individual conductors per strand. For those still using single-ended sources, a 4.4mm to 3.5mm adapter is included.
Five sizes of liquid silicone ear tips (XS through to XL) should accommodate most ear canal sizes, and the dual carry solutions – a protective pouch for everyday transport and a soft PU leather envelope for more serious storage – give you options depending on how carefully you want to baby your investment.
If I had to nitpick, the harder of the two cases, while functional and stylish, is not quite as fancy as the one Meze supplied with Advar, which is a shame because that case was quite something.
Design and fit
Meze has staked its reputation on creating products that look as good as they sound, and Astru continues that tradition while pushing the envelope on materials and manufacturing precision.
Each earpiece is CNC-machined from a single block of pure titanium – not titanium alloy, but the pure stuff – which gives Astru a distinctive lightweight (13.4 grams) feel despite its premium construction.
The multi-stage electroplating process that follows produces a smooth satin finish that feels refined without being overly flashy. According to Meze, each matched pair of shells requires up to seven days of precision processing, which speaks to the level of attention lavished on every unit.
It actually reminds me of the same horn-like speaker design first adopted by Advar, only lighter and less flashy, and is an absolute dream to photograph if you’re into minimalist metallic finishes.
The shell geometry itself has been carefully refined for long-term comfort, and it shows. Astru’s design prioritises a secure, stable fit that doesn’t rely on excessive bulk or aggressive angles, which really helps during extended listening sessions.
Without question, this is the most comfortable IEM I’ve had the pleasure of wearing, and that includes every single custom IEM I have along with my previous comfort champion, Sennheiser’s IE900.
The combination of tiny, rounded earpieces, wrapped in a skin-smooth metallic finish, with a short, stubby nozzle that places absolutely zero pressure on my smaller ear canals makes for a super easy fit, perfect seal and hours of extended, pain-free use every time. Closer inspection of the nozzle reveals a precisely made nickel wax guard, electroplated to match the titanium nozzle. It’s a small detail but one that adds to the immense satisfaction that comes from a thoughtful design.
That said, those of you with moon-crater ears will probably reach for the largest possible tip size, which even then might not be big enough to seal cave-like canals. You may want to have a selection of aftermarket tips on the ready before you try fitting Astru for the first time.
Tech and specs
Astru’s technical story centres on its single 10mm dynamic driver, which represents a deliberate departure from the multi-driver arms race that dominates the high-end IEM market.
Rather than layering multiple balanced armatures or hybrid configurations, Meze has invested heavily in engineering a single driver capable of delivering ‘flagship-level’ performance across the entire frequency spectrum.
At the heart of the new driver is a multilayer composite diaphragm that sounds almost absurdly over-engineered – in the best possible way. The dome features more than 80 ultra-thin layers of gold, applied during a 48-hour physical vacuum DC magnetron sputtering process. This gold-layered structure is then bonded to a titanium layer and mounted on a PEEK (Polyether Ether Ketone) base.
The combination is designed to balance the speed and control typically associated with lighter materials while retaining the natural warmth and physical impact that makes dynamic drivers so appealing for music reproduction.
According to Meze, the result is a driver that delivers fast transient response and extended treble while maintaining the visceral, full-bodied sound that single dynamic drivers do particularly well, something that (spoiler alert) I’m about to confirm in the sound impressions sections below.
The 5Hz–35kHz frequency range suggests genuine sub-bass extension and air in the upper treble, while the 32-ohm impedance and 111dB sensitivity rating make Astru relatively easy to drive from portable sources. Total harmonic distortion is specified at less than 0.1% at 1kHz, which is respectably low for a dynamic driver design.
Full technical specifications:
- Driver type: Single dynamic driver
- Driver size: 10mm
- Diaphragm construction: Multilayer composite with 80+ ultra-thin gold layers, titanium bonding, PEEK base
- Frequency range: 5Hz – 35kHz
- Impedance: 32Ω
- Sensitivity: 111dB SPL/mW at 1kHz
- Total Harmonic Distortion: <0.1% at 1kHz
- Input connector: 2-pin
- Weight: 13.4g (0.47oz)
- Shell material: CNC-machined pure titanium
- Cable: Premium balanced cable with 4.4mm gold-plated termination
- Included accessories: 4.4mm to 3.5mm adapter, five ear tip sizes (XS–XL), protective pouch, PU leather envelope
- Price: $899
- Website: https://mezeaudio.com/products/astru
Continue to sound impressions…
