Understanding Your Mufflers

By: Jim Brown

Ever heard of cars without mufflers? Well, get ready to cover your ears. Mufflers may look like some tube somewhere in the engine but you'd be amazed at what it can do with regards to a vehicle's noise level. Here are some top facts you need to know about them.

What is a muffler?

A muffler is a tubular acoustic device that is inserted in the exhaust system. It is designed to reduce noise. Inside it, you will find a tube set with holes on them. They work in the same manner like a musical instrument by reflecting waves that transmit sound caused by the vehicle engine. In this way, some of the waves are cancelled out.

How does a muffler work?

The key to knowing how mufflers work is to know and understand the concept of canceling sound first. To cancel out sound is to make a wave of sound that is precisely the opposite of some other wave.

This would mean that if the engine produces a certain sound wave, the muffler would produce the exact opposite of this sound wave consequently making the two waves out of phase. If the waves are out of phase, zero amplitude is produced called destructive interference.

So if the sound wave produced by the car engine is at the maximum, the muffler will be producing the same wave at the minimum. When the two waves hit your eardrum, you hear nothing because the waves when added add up to nothing. In order to cancel out sound, a tube set is found inside a muffler. These tubes are made to produce waves that reflect and get in the way with each other.

This is how it happens. The sound waves get inside the tube at the center into the muffler's body and then go into another chamber called the "resonator". The resonator, equipped with a specific length and some air, is the chamber that's responsible in creating a wave that wipes out a definite sound frequency. It is here that sound waves are canceled out. After going into the resonator, the sound waves take a turn and leave through the last pipe, leaving the muffler.

What are the other kinds of mufflers?

Glass Pack Muffler. This muffler works by simply absorbing sound waves to reduce sound. Active Noise-Canceling Mufflers. The system used in this type of muffler incorporates a speaker and a microphone set. A computer is utilized to monitor and give a signal to the speaker. Most industrial generators use this type of muffler.

Motorcycles
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 

» More on Motorcycles