Headphones — ROSESELSA QuietSea

The QuietSea is a one-driver IEM first released under the Rose Technics name and later carried by ROSESELSA. Its shell was designed by IKKO Audio and shares the form factor of the IKKO OH2, while the tuning was done by the Rose Technics acoustic engineers. A newer QuietSea II has since joined the range and keeps the one-driver concept.

Key specs that matter

Inside each shell is one 10 mm dynamic driver built around a topological diaphragm developed in-house. The rated impedance is 32 ohm and the sensitivity 99 dB, with a frequency range of 20 Hz to 20 kHz, and harmonic distortion is specified below 0.1 percent. The product weight is 20 g. A 120 cm cable connects through gold-plated MMCX sockets, and the product is sold with either a 3.5 mm single-ended or a 4.4 mm balanced plug. The silver finish is available with both plugs, while the grey version is listed only with the 4.4 mm termination.

Engineering and use context

According to Rose Technics, the diaphragm combines nano-materials with an optimised micro topological structure, a structure that reduces modal vibrations of the membrane and is credited with the low distortion figure. The driver sits in a dual-chamber enclosure, with the unit itself housed in gold-plated brass. The outer shells are zinc alloy, cut on five-axis CNC machines, and two vent holes are placed on each earpiece, one near the nozzle and one on the faceplate. The nozzle is oval, and the company says the angle of the sound outlet was set using measurement data from more than 700 Asian ear canals. The gold-plated MMCX sockets are rated by the maker for a longer plug-in life than standard parts. The stock lead is 5N OCC copper in a four-strand spiral layout. The box includes a hard carrying case, three pairs of oval ear tips and a small tool for removing MMCX plugs without straining the connector.

Pairing

The QuietSea is an undemanding load for phones, USB dongles and portable players, which drive it without a separate amplifier. Buyers who plan to use a player or dongle with a balanced output should order the balanced termination, as the plug is chosen at purchase. A desktop headphone amp with that balanced socket accepts the same balanced version directly. Because the MMCX standard is common, aftermarket cables are easy to find.

Alternatives

The QuietSea II is the follow-up ROSESELSA single dynamic model, using a PEEK and carbon-copper dome with a dual-magnet, dual-cavity motor.