magnaflow or corsa . it will be expensive .

 

What vehicle are these mufflers going on? That will determine how much room you have to work with, and as Pocket already said, a larger muffler case is going to be more effective at cutting noise down.

That link Austin Phil posted is suggesting the use of OEM mufflers - the link shows some Mustang GT mufflers, but there are obviously a million varieties out there. OEM systems tend to be quiet compared to most aftermarket mufflers. If you're installing these on a vehicle that has good room for a large muffler, then going with something off a V8 truck (Escalade, Expedition, Yukon, whatever) could work very well. If you don't have as much space, then some Vette/Camaro/Mustang/SRT/etc mufflers might work for you.

Personally, I have Borla XR1s with an X-pipe and full tailpipes on my Fox-body Mustang - sounds great, but drones on the highway, so I had some J-tubes added years ago, which helped quite a bit. On my CTS-V I've got a Corsa setup - quite expensive (fortunately I got mine used), but sounds awesome and has basically no drone.

 

I have 3" Pypes on my '81 Camaro with LS3. Interestingly I found the "Race" mufflers quieter than the "Street" mufflers. They are straight-thru mufflers with no baffles. There is some drone which I reduced with resonators.

 

Interesting, I always thought Pypes mufflers were a complete gimmick. Never knew a single person using them until I saw Merv and Vedit running them.

Now my interest is piqued as I'm a muffler weirdo and I like to run things out of the ordinary.

 

I've installed a few customer supplied Pypes kits. They're cheap, stainless and LOUD. Big cam cars that really want that racecar sound, that's your ticket

 

The vibrant ultra quiet resonator gets my vote as it’s straight thru like the magnaflow but they use better packing and they don’t burn out as fast.

id recommend 2-3 straight thru mufflers/resonators as this will be quieter but not restrict the performance or power.

oem mufflers like Camaro, corvette, mustang, and suv mufflers will be the quietest but will restrict power big time.

 

A female from work had the big tFlomaster mufflers on her Chevy Tahoe. It sounded really good IMHO.

 

Plus the bigger case sizes flow better for that reason.