Infinity Entra Series Owner's Manual page 4

For speaker connections, use a minimum $116~gauge speaker
wire with polarity coding.'& side of the wire with a ridge or
other coding is usually considered positive polarity (i.e., +).
ANTE If desired, const~lt your local Infinity dealer about speaker
wire and connection options.
The speakers have coded terminals that accept a variety of wire
connectors.The mosl common connection is shown in Figure 5,
To ensure proper polarity, connect each + terminal on the back
of the amplifier or receiver to the respective + (red) terminal on
each speaker, as shown in Figure 6. Connect the - (black)
terminals in a similar way. See the owner's guides lhat were
included with your amplifier, receiver and television to confinn
connection procedures.