Hydra 32 Mount question, will it get hot with this

[kris2for]

How hot do these hydra 32 get?

I wanted to wood router out a slot in the bottom of floating shelf to mount these. My other option is drilling a long screw or rail, but not as clean looking

 

[harley32907]

I run 3 32's maybe install a fan in the hood

 

[kris2for]

So dont router slot out