Easily setting the standard when it comes to home studio sound, the flat and neutral frequency response of Yamaha HS Series models, even despite the compact size, delivers everything that engineers and producers need in a studio monitor. The HS4 fills an important hole in the HS Series lineup. Unlike the HS3, the HS4 features a 4.5 inch woofer and 1 inch tweeter: a format and configuration that's perfectly optimised for engineering, production, writing and content creating in smaller studio spaces - but without losing out on sound quality. Class-D Amplification What makes both the HS3 and HS4 monitors so special is the Class-D amplifier that comes built in and controls both monitors at the same time. This doesn't just save weight, but means that your XLR, jack and RCA cables only need to be hooked up to one monitor, while a single cable links the pair. Both monitors also come housed in a robust MDF cabinet, which isn't just durable but helps reduce resonance to result in tight sound and, one of the best-kept secrets of these near-unrivalled Yamaha monitors has to be the Twisted Flare Port: a smart piece of tech that reduces the noise caused by air turbulence in the bass reflex port, giving you more defined and more accurate low-frequency reproduction.