[AHP Add-On] X10WavPlayer (Add Sound)

[Tuicemen]

Yes the power button must stay on!
If the Speaker has a power button you leave it ON so once x10 sends a on signal to the appliance module the speaker comes on.
I believe Walmart sells this type of baby monitor Dave_X10_L Got his there!
The wireless speakers I have work this way but are discontinued.
If you plan to use the X10 audio/Video sender it has a slide switch to keep it on/off
 

[HA Dave]

............... I think the baby monitor I have has the digital button, I will check. Hopeffuly I can find one with a real button

I found the cheapest baby monitors are the simplest and easiest to use. You could even pick up a baby monitor at a yard sale ($2-$5).

Also you can use an X10 Universal Module (UM506), to simply connect and/or disconnect a speaker.... or use any type of amplifier connected to an appliance module. For my outside speaker... I ran wire to a powered computer [amplified] speaker with a connection for a 2nd speaker, then I ran the 2nd speaker wire to a speaker outside. To broadcast the sound outside my macro merely turns ON the apliance module that controls the powered speaker.