Wavesfactory is giving away an AAX plug-in for free, SK10.
SK10 is an audio plugin that simulates a Subkick microphone. Add low end to your tracks in a very natural way without EQ.
SK10 is available for Mac and Windows in VST, Audio Units and AAX formats.
* Some users are reporting that after install only an 32 bit version of AAX is installed. Please bear this in mind, it may not work with your version of Pro Tools.