Subwoofer finally raised.

[Istoc]

So I built a small scale open air riser for my Sony 10" sub(70$ not a great sub but it seemed to do the job thus far) The instant I set it on the riser(Essentially 3/4" raise height) I felt like I had lost much of my bass impact. Would adding padding between the bottom of the sub and the floor which is currently open help replenish the bass without causing reverb(Which is the whole reason I raised the sub in the first place) or do you believe the only way for me to restore the bass without creating reverb is to get a more powerful sub.