Tough question to answer without seeing/hearing it. A speaker rattle can be caused by a blown speaker, a loose mount, or just too much bass/power feed to speaker. You can easily pull the speaker cover and check to make sure it is not loose. With stereo on, "feel" around and see if you can find a rattle. If you hear it, touch lightly around the speaker, on the mount, and around the door. May find something loose.
Check and make sure bass is not all the way up or stereo is very loud. In this case, all speakers would likely rattle, but you never know. The stock system is power limited, and good bass takes allot of power. "rattle" bass does not.
If neither of these stand out, speaker may be blown although I have not heard of many cases of this in Acura. Might get warranty work, or might consider installing aftermarket speakers. Easy home project, relatively inexpensive, and improves sound greatly. If you do it, use Dynamat on doors to help avoid door rattles....