350z Weird Exhaust noise
 

CSB

Heres a Video of how it sounds
 

Did you check for exhaust leaks? Seems like that would be the issue of unwanted noise.

If it's not any obvious exhaust leaks (have your hand near the joints to feel for escaping gas)...my next thought would be y-pipe.
If you have a Stillen Y-pipe (or one with no flexis), and straight pipes it's very very pronounced, sounds like a goose hissing or something usually around 3-2.5k rpm.
That was my experience with it, so I sold the Stillen.

Bad news for Bubb Rubb...he's gotta find a OEM exhaust for the 84 cutlass...

woooot woooooooo

is anyone surprised he's a raiders fan?

Sounds like a pressure issue so for sure it's a leak. Have you done any modifications to your exhaust? If you bought used it's possible the different exhaust parts don't match up nicely. Spending an hour or so underneath loosening some bolts, realigning and tightening things up again could help. You'd probably get a look at any bad gaskets around the same time too.