02 Camry V6 - loud knock or "tap" noise accelerating from dead stop - motor mount?

[scubacat]

I hear what sounds like someone loudly taps on some plastic when accelerating from a dead stop. If I accelerate gently, it doesn't happen. It began as soon as I replaced all 4 struts but it never happens over bumps which is what I would think would happen if it were a bad strut mount somewhere. Could it be the front motor mount?

How much movement is acceptable?

(Please forgive poor quality of this video. I'm apparently somewhat iPhone-illerate.)

http://youtu.be/f_rHxO7zG84