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Unread 08-25-2017, 03:52 PM   #2
Rich Z
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Join Date: Mar 2006
Location: Crawfordville, FL
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Name : Rich Zuchowski
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"Drone" is actually a sort of audible resonance that has a peak volume in our range of hearing. The most common range is usually in the 1400 to 1800 RPM range, which happens to be cruising speed in most of our cars. So it gets on most people's nerves pretty quickly because it becomes a constant loud hum while cruising down the road. When drone is really bad, you can pretty much rule out listening to the radio or having a conversation with a passenger while driving in the affected engine RPM range where the drone is most prevalent. And when it REALLY gets bad, the vibration created by the drone will cause other components in the car to vibrate when it is physically transmitted through the frame and creates additional noise as those other components audibly vibrate as well.

Some aftermarket exhausts are designed to eliminate, or at least reduce this resonance by either moving the peak frequency out of the audible range, or outside of the average cruising RPM range.

For a rather technical explanation you can try this document -> https://crgis.ndc.nasa.gov/crgis/ima...f_Mufflers.pdf

When buying an aftermarket exhaust system, it would be well worth investigating not only the claims of the manufacturer concerning drone, but to also solicit first hand experiences from actual users.

Now "drone" is not the same thing as "tone" of an aftermarket exhaust. "Tone" is basically the overall change in sound that an aftermarket exhaust system makes based on changed parameters in the design of the exhaust components. For instance, increasing the pipes from 2.5 inches to 3 inches, makes a generally deeper tone that people might call a "growl" or "rumble".
An exhaust system that is less restrictive to the movement of the exhaust gases are normally much less restrictive to the exhaust "noise " as well. Which is why a lot of people equate a "louder" exhaust to more horsepower.
And this is what people generally are looking for with an aftermarket exhaust. "Drone" is an unwanted, and generally unpleasant side effect of a less than well designed system.

IMHO.
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