I just used construction screws. With the woofer removed, I screwed a couple of screws through the back of the speaker, through the ceiling and into where I knew there was wood blocking. I did this with volt 6s but I wouldn't think twice doing it with volt 10s. You can screw directly into the ceiling joists if you can't get access to install wood blocking.
My current RSL atmos speakers sound great but they’re like 10dB less efficient than the rest of my system. I’d swap them out for Volt 10’s in a second once I figure out how to flush mount them. Matt posted some mock ups a while back of a wood piece that would allow volts to be ceiling mounted and run ib. If I had any router skills at all I’d be running these.
SPEAKERS: 3 x DIYSG 1099's LCR; DIYSG HTM 6's and 8's surround; 4 x RSL C34E Atmos; 4 x UM18-22 Mini Marty's.
COMPONENTS: Denon X4400; Minidsp 2x4 HD; 2 x Jensen Iso Sub 2RX; 2 x NX6000d; Epson 5040UB.