NOV 64 AUDIO OCEAN - High-End 6-Driver Hybrid Reference IEM with 32 Passive Acoustic Tuning Configurations

The 64 Audio Fourté was a defining model among the brand's universal in-ear monitors for more than a decade. Ocean builds on that legacy, but it is not a simple continuation. It brings 64 Audio's current driver, acoustic and tuning expertise together in a new system with extensive adjustment options.

Ocean starts from a dynamically neutral and detailed presentation with a rich, present midrange. Rather than imposing one fixed sound signature, it provides a refined baseline that can be adapted to the audio chain, individual anatomy and musical preference.

Each Ocean earpiece uses six drivers with an integrated four-way passive crossover. Two dynamic drivers operate in a true cone-to-cone isobaric arrangement for low frequencies, delivering substantial air movement and controlled bass from a compact in-ear monitor enclosure.

The midrange is handled by two balanced armature drivers, while a dedicated balanced armature unit covers the upper-midrange. The highest frequencies are reproduced by a tia high driver, part of 64 Audio's more open tubeless high-frequency acoustic approach.

The value of Passive Acoustic Control is not simply the number of available options. Ocean controls three separate acoustic areas independently, so increasing bass energy does not require a simultaneous change to isolation or high-frequency character.

This system allows Ocean to be matched more precisely to the source device, listening environment and individual ear-canal acoustics while retaining the factory reference tuning as a reliable baseline.

Ocean does not use three separate technologies side by side, but rather an acoustic system whose elements work together. tia focuses on the clarity of sound delivery and high-frequency energy, apex addresses ear-canal pressure and isolation, while LID is designed to make electrical behaviour more independent of the source.

This approach addresses three critical aspects of a multi-driver in-ear monitor at once: mechanical-acoustic resonances, the pressure sensation that develops in the ear canal and the influence of audio sources with different output impedances.

Ocean's shell and machined faceplate are made from T6061 aluminium in a Champagne Copper finish. Its surface pattern is inspired by aeolian ripples, the natural sedimentary forms shaped by moving wind.

The form is intentionally restrained compared with many visually extravagant flagship in-ear monitors. Its minimalist exterior brings focus to the technical details of the integrated acoustic system, interchangeable modules and precise mechanical interfaces.

Ocean includes two shielded 0.78 mm 2-Pin cables as standard: one 3.5 mm single-ended version and one 4.4 mm balanced version. This provides direct access to the two most common portable and desktop connection formats with the same in-ear monitor.

The four-core cross-braided Litz cable uses silver-plated UP-OCC single-crystal copper. It contains 99 strands per core, has a total impedance of 0.29 ohm and uses shielding to support orderly signal transmission.

Ocean's 9.5-ohm impedance and 103.7 dB/mW sensitivity represent an easily driven electrical load, while LID technology helps the tuning behave more predictably with different sources.

The two included cables allow direct connection to 3.5 mm single-ended and 4.4 mm balanced outputs without purchasing an additional accessory. After every new configuration or connection, it is advisable to begin with the volume of the music player or DAC/amp set low.