Would spikes help me?

I have Tyler PD80's with sub amps built in. They are 65 inches tall and weigh in at around 230 ponds each. Right now they are on carpet over a wood floor. There are no feet on the speakers whatsoever, so the base (18X14inches) sits flat on the carpet. I really think they should be sitting on something. There are threaded holes on the bases they look to be 5/16. What could I expect if I were to add spikes? If I did add spikes, which spikes would you recommend?

Thanks