The RS ONE is Acoustune's first monitor earphone, and is a standard monitoring earphone designed with emphasis on robustness and monitoring performance - critical aspects for professional on-stage use. The RS ONE utlises sound quality technology cultivated in Acoustune's HS series and the knowledge gained from the ST1000.

RS ONE has been designed to avoid the problems that tend to occur with in-ear monitors, such as broken nozzles, damaged connectors and housings, and poor cable contact. At the same time the RS ONE has a small earpiece that anyone can wear, a cable that is easy to handle, and impedance that matches the earphones and ear-monitor systems.

Acoustune has minimised the number of parts in the RS ONE and thoroughly researched the most fragile parts of earphones to create a highly robust body.

The housing consists of two parts made of polycarbonate, which is highly resistant to impact, weather, and heat. By reducing the number of parts as much as possible, Acoustune has achieved simplicity and increased the rigidity of each part, greatly reducing the risk of failure even in harsh environments. The face plate part plays a role in increasing the rigidity of the body while giving it an identity as an ear-monitor. In addition, the small size of the housing design makes it suitable for a wider variety of ear shapes.

The Myrinx EL driver is a driver that provides more accurate monitoring than Acoustune's standard Myrinx driver. The material used in the Myrinx EL is an ultra-high performance resin that is used in medical applications, yet is lightweight, extremely rigid, and has high internal loss for extremely high acoustic performance. The high internal loss reduces unwanted noise and improves monitoring performance.

In addition, in order to take advantage of this Myrinx EL driver, the back cavity at the back of the diaphragm is secured at a large distance from the diaphragm to the grille to achieve a high input resistance that allows normal use even after an instantaneous sine wave signal input of up to 250mW. This gives the earphone speakers a robustness that prevents them from being damaged even in the event of sudden large inputs. The large stroke width of the diaphragm gives the earphones a loudspeaker-like live sound, but with the accuracy of earphones for excellent monitoring on stage.

Stage monitors are used in combination with wireless earphone systems. If the impedance of the earphone is not matched to the earphone system, the monitoring performance may be degraded due to loss of volume or changes in the characteristics of the earphone. In order to avoid such problems, the Acoustune has selected the optimum impedance to minimize compatibility problems.

The new Pentaconn Ear cable connector used in the RS ONE is designed and manufactured by Nippon DICS Corporation and boasts high sound quality and reliability. Compared to conventional MMCX connectors, the plug and jack portions are in closer contact, resulting in superior conduction performance. It is also easier to attach and detach, and more robust.

The 'ARM011' cable included with the RS ONE uses high-purity Litz wire and Kevlar wire braided together, and is covered with PU material to make it easier to manage. Compared to other connectors, the Pentaconn Ear connector reduces the risk of contact failure due to wear and sweat caused by connection and disconnection, and offers high reliability, reducing the risk of accidents in production environments.

Three sizes (S/M/L) of AET07 eartip are included with the RS ONE. The AET07 is used as the standard reference eartip for Acoustune earphones. A pair of AET02 foam eartips is also included for a sealed feel that only foam tips can provide.