How do you move HEAVY speakers with sharp spikes without lifting?

I have large (175 pounds each) speakers with sharp spikes placed on carpet. I would like to be able to move them a few feet by myself to tweak their positions but lifting them is obviously not an option (I can't even lift half their weight).

I currently use a convoluted method involving tilting them over about 30 degrees, slide a board under spikes on one side, and then repeat on the other side. The speakers almost toppled over the other day which would damage them.

I'm aware there are non-spike alternatives but do not have the money to spend on these options. Any clever moving methods out there? 

Thanks!