How to wire this component (-4dB audio)
The -4dB refers to the voltage at the output. You can completely ignore it as it's pretty much meaningless unless you're working with professional audio equipment.

The only part you are interested in is the phrase "Line Output" and this indicates to you that it is a "line level" audio signal - i.e., one suitable for connecting to the "Line Input" port of an amplifier or similar piece or audio equipment (i,e, it can't directly drive a speaker, it needs an amplifier).

You connect the "-4dB Line Output" to the center pin ("tip") of your jack, and the outside "sleeve" to ground.  If there is a middle "ring" pin that can be connected to the "-4DB Line Output" as well.