Principles are simple but getting the low sound isn't.
If you look at a guitar or piano the larger the "string" the lower the note.
If you look at a pipe organ the larger the pipe the lower the note, the same air goes into the smaller pipe and larger pipe, but the notes that come out are different.
Trumpet and Tuba.........
Tweeter is small speaker(high frequencies), woofer large speaker(low frequencies), so that's the general principles, larger = lower frequency
Lower frequencies travel farther than higher frequencies because they are longer "waves",
This is why you can hear the subwoofer thumps of the guy 4 cars behind you at the stop light but can't hear the song(higher frequencies), lol.
So when "they" design a muffler they want to muffle the low frequencies, because that is the hardest "noise" to get rid of.
You don't want to change the headers(exhaust manifold) to the Cats, that part of the system is designed for best performance(creates low pressure at exhaust valves), but after the Cats you can use a larger diameter pipe size, just like a pipe organ, long and straight as possible.
Mufflers are an issue but some are designed to leave a bit of the low frequencies, designer mufflers, lol.
But the smaller pipe after the muffler will pretty much kill what little low frequencies are left
Last edited by RonD; 10-16-2014 at 11:26 AM.