ok - there is a mis-conception on quiet with Carbon Fiber Barrels.... if anything they can sound tin'ny and hollow. (Hard to describe)
Since you already have Freak Inserts - maybe you should pick up the Deadly Wind Fibur barrel with out the inserts. Very economical that way.
Now- I love my Deadly Winds Carbon Fibur Freak kit, however I can say that the Freak with All American Tip is more quiet, or changes the sound enough to appear more quiet, because it has So MUCH more porting.
If you are looking for a quiet tip for your Freak Back - just make sure the one you buy has allot of porting! This will help you for your quest for quiet.
I also have the Deadly Wind Tip for UL (Dye UltraLight Barrels) and the Dye Tip is more quiet, your biggest gain with the DW tip is the weight savings. And honestly on the field - it doesn't matter, cause once you start laying a ROPE everyone knows what's going down, and where you're at.
Hope this helps...
My Current Markers:
(Exclusively Using Monkey Poo Lube
/ Gun Sav Lube
MacDev Clone GT
Black/Green = Ninja Air 550psi 70/4500 = Seed Rotor
Black/Green (Pooty51 Polished NDZ Can/BubbleGum Flat Face Bolt) = Ninja Air 550psi 70/4500 = Seed Rotor
Black/Green = Ninja 550psi Reg'd Crossfire 70/4500 = Seed Rotor
DigiCam Midnight (Virtue OLED) = Ninja Air 68/4500 = Seed Rotor
Midnight = Ninja Air 68/4500 = Seed Rotor
Champagne (Pooty51 Polished Bolt / Virtue OLED) = Ninja Reg'd CrossFire 70/4500 = Seed Rotor
. . BattleField Orlando