オーディオテクニカ ATH-AC5TW オープンイヤー型 ワイヤレスイヤホン Bluetooth 5.4 IPX4防水防塵規格 ながら聴き マルチポイント 低音域補強技術 最大約34時間再生【国内正規品】 ブラック

## Audio-Technica ATH-AC5TW Review: Open-Ear Wireless Earbuds That Keep You Connected The Audio-Technica ATH-AC5TW represents Audio-Technica's entry into the growing open-ear wireless earbuds market. Utilizing air conduction technology, these earbuds sit outside your ear canal, allowing you to enjoy music and calls while remaining fully aware of your surroundings — a listening style often referred to as "nagara-giki" (while-listening) in Japan. ### Comfort and Everyday Usability The open-ear design is the standout feature here. Because the earbuds don't insert into your ear canal, they eliminate common issues associated with traditional in-ear designs: ear fatigue during extended use, moisture buildup, and that uncomfortable plugged-up feeling. For commuters, remote workers, and anyone who wears earbuds for hours at a time, this is a significant benefit. Phone calls also feel more natural since your own voice doesn't sound muffled or hollow, allowing for comfortable, natural conversations. ### Sound Quality: Large Drivers and Dual Bass Enhancement Audio-Technica has equipped the ATH-AC5TW with a large 17×12mm oval driver that maximizes the limited acoustic space within the housing. Behind the driver, an acoustic space and acoustic duct are strategically placed to control airflow, enabling optimal driver movement for rich sound reproduction. The real highlight is the proprietary Dual Bass Enhancement Technology. This combines a digital processing algorithm for low-frequency reinforcement with a dynamic EQ algorithm that maintains bass presence even at low volumes. Open-ear earbuds typically struggle with bass reproduction, so this dual-approach technology is a thoughtful solution from Audio-Technica. The result is a well-balanced sound with satisfying bass presence that defies the open-ear form factor. ### Battery Life and Multipoint Connectivity Battery performance is impressive. The earbuds deliver up to approximately 13 hours of continuous playback on a single charge, and with the charging case, total playback time extends to approximately 34 hours. This is more than enough for a full day of use without worrying about running out of power. The ATH-AC5TW features Bluetooth 5.4 and supports multipoint connectivity, allowing simultaneous connection to two Bluetooth devices. This means you can stay connected to both your smartphone and your work PC or tablet at the same time. If a phone call comes in while you're watching content on your tablet, you can answer immediately without manually switching connections. ### IPX4 Water Resistance With an IPX4 water and dust resistance rating, the ATH-AC5TW can handle sweat during light exercise and unexpected light rain. This makes them suitable for active daily use without concern. ### Verdict The Audio-Technica ATH-AC5TW is a well-rounded open-ear wireless earbud that leverages Audio-Technica's audio expertise to deliver a compelling package of comfort, sound quality, and practical features. Currently available on Amazon Japan at ¥10,255 (31% off the regular price of ¥14,960), it offers strong value for anyone looking to embrace the open-ear listening experience with the reliability of a trusted Japanese audio brand.