John
B.A. Not Baracus’ Bad Attitude but Balanced Armature — technology originally developed for hearing aids but that successfully made the jump to deployment within in-ear monitors (IEMs) as an alternative to dynamic drivers. Smaller than a dynamic driver, balanced armature drivers are generally limited to a specific frequency range where IEM designers will stitch several together, with a crossover network, inside an IEM’s earpiece to ensure full coverage of 20Hz to 20kHz.
First announced in March 2021 but only brought to my attention last week via a press release, 64 Audio has gone beyond common industry practice to install 18 (yes, eighteen) BA drivers inside their all-new U18s universal IEM.
From that press release: “In 2016, 64 Audio revolutionized the IEM industry with its world-class reference level U18t, the industry’s first 18-driver earphone. Now, with the U18s, 64 Audio has taken the heritage of the 18-driver platform and further pushed the envelope of innovation in sound and design. The U18s combines proprietary drivers, LID technology, and a new electronic crossover network to deliver a uniquely exceptional listening experience.”
Inside each U18s earpiece sits: 1 x (tia) high driver, 1 x high-mid driver, 8 x midrange drivers and 8 x bass drivers, all integrated by an electronic 4-way crossover. The driver assembly/install process takes place under a microscope:
According to 64 Audio, the U18s earpiece “is handcrafted in the USA from aerospace-grade aluminum billet. CNC milled, sandblasted, fly cut, and twice anodized”.
We might ordinarily expect to mate the U18s’s 8 Ohm nominal impedance with a headphone socket whose output impedance is well below a single Ohm. However, 64 Audio’s LID technology reportedly “ensures a consistent frequency response regardless of the source, making it perfect for musicians plugging into a variety of equipment.”
64 Audio’s website tells us more: “Smartphones, body packs, amps, and DAPs produce audio with different output impedances. The interaction of the earphone impedance curve with the sources may result in the same IEM sounding different with different sources. LID mitigates these inconsistencies, so you can enjoy the same sound across sources.”
That same website also explains ‘tia’ as a “tubeless design that reduces resonance for a transparent and lifelike sound signature”.
Shipping in the box with each pair of U18s are the following accessories: a leather protective case; TrueFidelity eartips (S, M, L); silicone eartips (S, M, L); SpinFit eartips (S, M, L); ear tip holder; 48-inch 8-braid silver premium cable; round 64 Audio sticker.
Also found in the box are three of 64 Audio’s Apex (‘Air Pressure Exchange’) modules – the m20 (-20dB), m15 (-15dB) and mX (-10dB) – that allow end-users to vent/isolate the IEM according to taste in order to help reduce listener fatigue, widen the soundstage and preserve low frequencies.
Pricing? I hope you’re sitting down: the U18s sell for a cool US$2999 per pair.
Further information: 64 Audio
