Guys, I'm getting a head rush from an errant inspiration. Quite awhile back, at a coffee shop, some kid came in with cylinder shaped device that was a speaker, an exciter to be more exact. I didn't really care, cuz it is just another mindless fad device...go away....but then, he puts it on the counter top and it sounds kinda good. And then he puts it on other surfaces and it sounds different on each. No surprise so far. Next thing i know he is outside and places it on the big picture window, and I am hearing sound that shouldn't be this good. Blows my mind, and in time I forget about it. Yah, the Parts Express catalog comes and I look at the various models. Not one clue what I would do with one of these things, but for $20-40, it could be fun. Ok, you read this much, now you tell me, you guys have any experience with these things? And so, what do you think? I even saw a hybred exciter using a ribbon for high frequencies. Hmmmm

A couple years ago a friend showed me how when he played music through his iPhone when holding it, it was a quiet whine but when put on a solid surface it bloomed.  I guess it transferred the vibrations and used the surface as a soundboard.  (Sort of the opposite of what some of use are trying to achieve with our speaker isolation at home.)

Is this the principle of the "exciter" that you saw?  Or is it something different?

Seems like wood would be good.  What kind of wood is a piano soundboard made from?  Or a violin?

And I think the wood might be shaped across its thickness to tune it to the sound?  Gets complicated!

 These are great observational discussions. That is the intent for me asking. No doubt, this could become an actual science project for sure. That's when I see those folks out there with a lab, personal, and funding at their disposal to contemplate 'what if?' at a great advantage in life. Yes, Steve is one the few. Wouldn't surprise me if he hasn't already crossed this bridge at some point before me.

Well, the instructions that I read said that wood was not the best conductor for these. I'm thinking that it has to do with  mass, and the fact that these don't likely have a load of power to begin with. You can however place more than one on a single surface to enhance bass and treble. Interestingly, you would not use a symetrical pattern for this.