How much power in watts goes to the factory center channel speaker?

I was looking into getting the Kenwood DNX9140 head unit because it has a center channel output. But it is a pre-out so I would need an amplifier. Kenwood sells a 20w center channel amp, but it comes with a speaker. So I would just not use the speaker and keep the amp. So I wanted to know what the factory output was for comparison.

Also, does anyone know of any low wattage mono (or bridged) amplifiers to power a single speaker in the range of 20w-50w?

Another related ?
Would I be able to use a 2-channel amp at 25W x 2 channels and just hook it up to the non-bridged + and - output terminals and still only get 25W for the speaker?

 

This is a Kicker amp that I will use for an example. These are the specs...

*2-channel car amplifier
*25 watts RMS x 2 at 4 ohms (50 watts RMS x 2 at 2 ohms)
*100 watts RMS x 1 bridged output at 4 ohms (4-ohm stable in bridged mode)

So these are some illustrations of some crazy ideas I had for wiring the speaker to the amp. Just let me know if either of these would work?? Or if neither would work.

 

Just wire it in bridge mode and adjust the gain so it's balanced. You won't blow the speaker unless you go completely apeshit with your volume and start clipping the amp.

 

Ok. Bridged for this amp would be 100W. If the speaker is rated at 40W I can do this as long as I keep the center channel volume low. Is that what you're saying?