Effortless setup phenomenal sound. When you combine the Mackie CR8S-XBT 8 Monitor Subwoofer with your speakers youll never want to switch it off. Providing professional studio-grade bass this high-performance sub is the ideal addition to any studio multimedia or audiophile system. Get flexible. This high-performance monitor subwoofer lets you adjust the input level of your sound sources with ease as well as the crossover frequency polarity and subwoofer output level. So you can dial in the perfect sound in seconds directly from the back of your sub. And with the included CRDV volume control optimising the levels of your system is even easier. You can even connect Bluetooth-enabled devices to your sub for wireless audio streaming. And even if the speakers you have connected to your sub dont have Bluetooth the subwoofer will act as a receiver and allow you to play your music through your system with ease.