Adjust the bass drum legs so that the front of the drum is an inch or two off the ground and the drum is resting at a slight angle. This shifts more of the drums weight onto the legs themselves and helps the spikes dig in more effectively, which should put an end to most bass drum creep problems.
Sometimes, especially for those of us kicking the drum pretty hard in loud situations, setting up on a carpet is just not enough!
Here is an additional little trick that will END bass drum creep problems.
Take a three foot long 2?x4? piece of wood. I have some nice fabric glued around it to make it look pretty, provide some protection to the drums, and prevent splinters. Now mark your carpet where you want the front of your bass drum to sit. Drill three quarter inch diameter holes through the wood ? one hole in the middle and one near each end.
Using some nice, big, 2 inch washers and 1/4 inch thick bolts ? actually bolt the wood to your carpet at the front edge of your bass drum. Make sure to put the flattest part of the bolt on the under side of the carpet so that your carpet still lays pretty flat. I also like to put a layer or two of gaffer?s tape over the end of the bolt so that it does not scratch up any nice wooden floors that happen to be underneath the carpet.
Now when you set up just slide the front of the bass drum right up against the piece of wood you have bolted to the carpet, and it will not slide any further!
It works best if you get the wood wide enough that the legs themselves actually bump up against the wood block although it will work fine with the rim of the drum against the wood block - just be sure to cover the wood with foam or thick fabric to prevent the wood from damaging the rim and lugs of your drum!
Let me know how well it works for you.