Epson ActionPC 2000 Read This First Manual page 15

Note
You can install C-type batteries in your speakers or obtain a
DC 6-Volt input jack to power the speakers independently
and use them as amplified speakers. This will boost the
speaker's bass response and allow you to adjust the volume
using the speaker's controls. If you do this, be sure to set the
Amp switch on the back of each speaker to the On position
and turn on the speakers before you turn on your system. Be
sure to connect the speakers to the OUT connector on the
sound card, as described below.
Before you connect your speakers, locate the battery
compartment on the back of each one. Inside the compartments
are the cables you use to connect the speakers to the computer.
Remove the cables. If necessary, attach one of the cable's wide
connectors to the socket on the back of each speaker.
If you are using your speakers as unamplified speakers, you
must do the following before you connect them to your system:
Turn off your computer
If there is a power button on the front of each speaker, set it
to the Off position
If there is an Amp switch on the back of each speaker, set it
to the Off position to turn off the speaker's amplifier.
Caution
Do not connect mono speakers to the OUT connector; you
could damage the speakers' amplifiers.
12 Read This First