What’s your sound preference? Mild? Moderate? Aggressive? No sound at all? Maybe you want a different sound depending on what and where you’re driving. You want an aggressive tone for your 1972 Dodge Charger that you lovingly restored, and a “less noticeable” tone for the Subaru Outback you use to shuttle the kids back and forth.
No matter what your harmonic preference or what you’re driving, there’s a muffler that will deliver exactly the sound you’re looking for. Welcome to the world of mufflers and sound enhancements—increasingly popular modifications that can personalize your ride.
A quick history lessonMufflers aren’t a new invention. Records from the U.S. Patent Office show that a patent for an engine muffler was awarded in 1897 to Milton and Marshall Reeves of the Reeves Pulley Company in Columbus, Ind. Mufflers in the early 1900s featured a “straight through” design that is still popular today. Essentially those early mufflers consisted of a pipe with holes, wrapped in something similar to steel wool, with the pipe passing through an outer shell. A big change to that early design occurred with a switch to a fiberglass packing material in place of the steel wool. Contrary to the name, a muffler isn’t just muffling the sound. It’s actually destroying many of the sound waves. But let’s back up for second.
How mufflers workThe two types of mufflers that most DIYers have heard about are a chambered muffler and a straight through or “glasspack” muffler. Here are the differences between the two (and a third, just for fun):
- In a chambered muffler, the sound waves generated by the engine at the end of the exhaust stroke enter the muffler and bounce around the muffler’s various chambers. As they do, they encounter friction which destroys some of the sound waves. Some of the sound waves that aren’t destroyed by friction bounce off a chamber wall and form a sound wave that’s an exact opposite. Those two sound waves cancel each other out, further reducing the noise that the vehicle produces.
- In the straight-through muffler design, the sound waves pass through a straight pipe, with some of the waves being absorbed by the material surrounding the pipe, much like the earliest mufflers.
- A third type of muffler design is a turbo style muffler in which the exhaust gases are forced into an s-shaped pattern and are peeled off and deadened by the muffler material.