The alpha 8a turns out to be more flexible than I imagined. I was able to shrink the box quite a bit and still have a nice flat response curve. I went with the Vifa tweeter. If the upper frequencies are too mismatched, I'll convert the other two boxes. I'm not going to try to chase down a Motorola piezo. The Vifa is a nice driver. The best part is that the speakers are high enough off the ground to keep them out of my 4 year old grandson's curious reach. (He poked in the dust cap on one of my 3 PI speakers last month.)