The standard 1446 will not work because the custom version used in the Volts has a different ohm rating. The crossover design will not work properly. I've contacted Eminence to get a current price on more Volt-10 woofers and waiting to hear back. Another option would be to go with two Volt-8's which pretty much sound like Volt-10's.
Thanks for the clarification Erich, I had noticed the different impedance rating on the custom CD so figured it might be the case. I have a while before I need to address the Atmos speakers, so hopefully your enquiries with Eminence will bear fruit. I will keep an eye on the website.