Most average brands of in ceiling speakers are rated for a wattage that will be sufficient. Volume controls come in 3 different configurations. 70v, wattage style, and wattage with impedance matching.
70v are typically used in commercial applications.
A volume control that is rated for 80w (+/-) and 4-8ohm speakers are pretty common for whole house use. As are the type with impedance matching abilities.
The difference in the last 2 are - if you plan on using more than a couple of pairs of speakers, and only 1 stereo amplifier or receiver, you should use something to regulate the speaker impedances, otherwise you run the risk of damaging your amplifiers.
There are speaker selector boxes which do this, or volume controls with small tabs you set based on the number of speakers being connected to your system.
Even if you are doing all this yourself, you need to plan it out, and
maybe somewhere that you are purchasing equipment can look things over and ensure you are getting the right combinations.
I need some help figuring this whole house audio "formula". I was already told speakers should be 1.5 times the amount of the wattage from the amp. Now I need to figure out the volume control.
1) Channel on a receiver (80W)
2) In-Wall SPeaker (7-75W reccomended)
3) Volume Control (60 watt to peak power rating of 120.