Exhaust, flaring sound - to be fixed?

[stopintime]

Termi cans, Spark midpipe, ECU, open airbox, runs smooth, 10,000 miles and under warranty.

There is a flaring sound when revving from idle - like a piece of stuffing is loose in there.
The sound is the same when running cold and warm engine.
I don't know if it is from one or both pipes (no, I will not put my ear down to check)

Is it possible that something is loose already?

[NAKID]

The baffling could be loose in there. I would take it in to the dealer since it's under warranty...