Aiwa SC-A2Y

Many manufacturers of personal stereos (Walkmen) offered speakers as an optional accessory. These SC-A2 from Aiwa are an example. They measure 170mm tall, 100mm wide, and 100mm deep, and they contain 92mm full-range speaker cones. They can be powered 3 ways: With 4 D-cell batteries (for each speaker), or with an AC/DC power adapter (Aiwa AC-621), or with a direct-in jack. If you are powering them with batteries, power is automatically switched on or off in response to input signals. So if you want to play music at extremely low volume, you should use one of the other 2 power methods instead.