All-in-One Speaker. DW's all-in-one speakers are designed with powerful amplifiers and signal processing (DSP) to ensure that every voice message is clear and easy to understand. The speaker has an on-board memory that can store pre-recorded voice messages, music, and alerts. The DW-SWSP30M model also includes a built-in microphone, which enables operators to respond to notifications or audio from the field with live communications.