turbo flutter

[rdodd]

I put the pdr hx-35 on my truck a few years ago and took the silencer out after putting it on. Yesterday, i put the ring back in and now i notice a flutter like sound when i get on it and quickly let off. Is it normal to get this flutter sound with the silencer ring in? I never noticed it with ring out.

 

[rdodd]

Could this flutter like sound be the same as turbo bark? I think i read that the hx-35 would eliminate turbo bark.