Regular speaker wire is unacceptable for in-wall use. The Volume Stabilizer detects fluctuation in audio and video volume level and corrects it before it bothers you. This device will do it for you automatically. To connect more than one set of speakers to an amplifier in parallel, you need to adjust for the impedance drop. For outdoor use with included PVC surface mount box or flush wall mounted.
Impedance match allows use with multiple speakers or singly.