I don't think it would do any harm to the woofers.
My practice is that I always turn the pre amp on first and then the power amps. When turning them off, I turn the amps off first and then the pre amp. That way, nothing affects the woofers.
I learned a lesson a few years ago. I got a tube pre and a SS amps. When I turned off the pre amp first, a surge went to the amps and blew the fuse and some other things in the input stage. I ended up sending the amps back to the factory to repair.
My practice is that I always turn the pre amp on first and then the power amps. When turning them off, I turn the amps off first and then the pre amp. That way, nothing affects the woofers.
I learned a lesson a few years ago. I got a tube pre and a SS amps. When I turned off the pre amp first, a surge went to the amps and blew the fuse and some other things in the input stage. I ended up sending the amps back to the factory to repair.