[1999cutiger]

I just recieved my CSS SDX15 subwoofer and I am shopping around for some suitable mounting screws. I know that I am supposed to use T-nuts, but I am not sure if there is a specific screw I am supposed to use. The mounting holes on the subwoofer a deeply recessed and it is hard to see what type of screw head is needed to sit flush. If anyone can point me in the right direction I would greatly appreciate it. I know some people use the black hex head screws. Are these necessary?

Thanks!