Subliminal Talk

Can I use masked subliminals using speakers or will I get no effect at all? If I can is the effect the same or worse than doing ultrasonic over speakers?

Also what is the number of recommended decibels? I can't seem to find this on the forum. Thanks in advance.

Yeah that's fine, you can use whichever one you want on speakers.

You just want it at a comfortable volume so you can hear it from where you're listening.