How does the sound compare between these two?

 

They are the exact same exhaust. Pettit just tacks on a couple of hundred dollars.

 

You might also want to consider the rb single. It's a little more aggressive, but it has a nice deep tone.

 

Is the single as mellow sounding as the dual?

 

I haven't heard the dual in person, but the rb single puts out a low mellow tone compared to N1's and other straight through style muflers. I think of it more as a low conservative note.

 

BTW, I heard an FD go by at about 45 mph today running the N1 duals. I absolutely hated the sound. To me, it sounded like any other obnoxious fart-can exhaust on any number of Civics around here. It did look cool though.

 

I have the RB dual tip as well as a 3" DP on my FD and is pretty quiet still. Has a nice low tone and very mellow sound. I haven't heard the single tip RB, but I've been told that they are very similar. I can say that the RB is one of the best sounding exhausts for the FD, in my opinion that is. That's my 2 cents.

Zach

 

The RB dual tip is the way to go for a discreet exhaust. I run a DP/MP/RB dual tip cat back and it is as civil as can be until you open it up. Cruise and general regular driving it sounds great, doesn't resonate in the cabin, and when you open it up it 'll talk to you. Mazda should've used that exhaust for the stock part Can't comment on the single tip, but the dual attracts less attention. Most people don't even think I've swapped exhaust systems.