How many ohms for the Vista woofers?

[rabident]

I want to bi-amp my Vistas. I have a 6 channel classe cav75 and was hoping to bridge 2 channels to drive the woofers. 75 watts to each panel, 150 watts to each woofer. But the amp will roast itself in bridge mode if the woofer presents a 4 ohm load or lower.

 

[risabet]

I would assume a four ohms load. Keep in mind that the difference between 75 watts and 150 watts is only 3dB so you may want to run the amp unbridged. My $.02.