Quietest Aftermarket Exhaust System

This may seem like a weird question but I want to hear the V4 sing but still stay close to stock in volume. I run a stock Harley Dyna muffler (cheap as they usually come home from the dealer's in the box the replacement came in) on my S40 that lets it thump nicely but still quiet. Same with the MagnaFlow cat back on my turbo Subaru. I went through my loud pipe phase many years ago but would like just a tough more of the beautiful sounds. Thanks in advance.

 

I haven't heard alot of slip ons but I have the Leo Vince EVO II slip ons. EVO II comes with the quiet baffle inserts. They sound as quiet or possibly quieter than stock. I proceded to take a pipe cutter and shorten the insert length a few centimeters at a time until I reached the volume / loudness I wanted. With the inserts out, it's pretty loud.

 

I like this approach, fine tuning by ear. Am I correct that the CF cans tend to be deeper/more mellow sounding?

 

its my understanding the construction material of the can doesn't really make a real difference on sound. I've adapted a Leo GSXR1000 can to my FZR. It's aluminum. I just bought another GSXR1000 can for my current project but in carbon. Both were new when I bought it. (its nice to be so close to the Leo Vince HQ). Both sound about the same on the FZR.

 

I have the Two Brothers slip ons on my bike, quiet throaty sound gets attention.

 

I own these, they're a bit louder than stock for sure. Nothing roaring, but with the baffles in they make a great sounding purr at idle with a nice growl as you roll on. You won't hear them at highway speeds.