Is it the clutch??

Have you adjusted the clutch yet ? Its super easy to do and takes no tools. Check your owners manual. I've posting how to do this in almost ever is my clutch screwed up thread I've ever seen.
 
I hear the sound you describe, it almost sounds as if another car is passing. a WOOOOM sound lol Maybe it is your shifting it also kinda sounds bogged durring the **** is your intake all nice and tight? HArd to tell on here