Alto TS4 active PA speakerIntroducing the Alto TS4 active PA speaker Where TS3 exceeded expectations, TS4 redefines them completely. Building on the legacy of our best selling TrueSonic speakers, the TS4 series delivers increased power, clearer sound, and advanced Bluetooth functions including streaming, speaker linking, and App control. Compact, lightweight, and designed for reliability, the new TS4 series makes it simple to get great live sound at every event. True sonic