[1Bad62Pro/Street]

You can definitely tell the difference in sound when you add a H-Pipe or X-Pipe.
I can vouch for that being around Hot Rods, Muscle Cars and owning Mustang GT's and having friends with late model mustangs, camaros, Firebirds.

Yep.....
X-pipe and H-pipes synchronize the balance of the exhaust pulses from each bank of cylinders based on firing order which increases velocity and scavenging from each cylinder. Most people agree that X-pipes are better at improving performance than H-pipes, especially at the top end. However, H-pipes tend to have a deeper sound than x-pipe equipped vehicles and generally build power down low. That's why I like H-Pipes better due to the deeper sound & low end torque.
An X-pipe's greatest advantage is due to the bends are smoother at the convergence, the flow and scavenging are both better, and hence the X-pipe is worth more power. All H-Pipes and X-Pipes are not all made the same as you can see on Jegs and Summit website. And the sound is different with different headers, mufflers and the way it's cammed. Most H-Pipes to me sound better with a chambered muffler. I can't remember if I ever heard an X-Pipe with a canister style muffler. I want to add an H-Pipe on my truck later. Right now the exhaust system is temporary. Although I have been getting way too many compliments on Dad's Homemade Drive Shaft Mufflers.

There made out of what? Dang....
Old School Cool