A multi-level amplifier uses more, but smaller, transistors for delivering power to the speaker. This way, switching activity and power losses can be reduced significantly and more power is delivered to the speaker.
INTRODUCING THE SIMPLEST WAY TO CONTROL YOUR ENTIRE HOUSE
YOUR VOICE. Imagine this... We've all been there-walking through the door into a dark house, arms full. Wouldn't it be nice to tell your house to offer a helping hand? Now you can. A simple voice command-such as "Alexa, turn on Welcome"-lights up the hallway and kitchen, fires up your favorite Pandora station, while the door locks itself behind you. This is Control4 Home Automation with Amazon Alexa.