I was asked if I have resonance with my new exhaust.

To me, resonance is when the change vibrates in the ash try and cup holders.

Anyone have a different description?

If this is right, I have no resonance...

 

It's when the car is humming loudly as you drive. It does not necessarily vibrate anything in the cabin. It's clearly an exhaust noise, but a very unpleasant one, and one that is not really tied to heavy throttle.

 

It's when, at a certain RPM and unaffected by throttle amount, the exhaust tone "resonates" through the passenger cabin, getting very loud. If you just slow down or speed up a little bit it goes away.

 

My new cat-back Flowmasters are a little louder and deeper sounding than stock. At highway speed they remind you there is enough power to pass that Honda before the passing zone ends. Cops don't notice the sound and I like it so it stays.

 

Early L98 stock exhaust are masters of the loud droning resonance. It's like they want you to mash the pedal everywhere you go because that's the only time the engine would sound great. You'd be surprised though, after a while the resonance becomes a white noise so to speak.

 

That's why manual trannys seem to have less resonance than autos because they can easily accelerate past that certain RPM range. Where as the auto seems to struggle getting by it. Although with either at WOT resonance is not there. Mainly because it is at the 1200 to 1600 RPM range.

 

So the exhaust is loud, but no resonance...

I don't get that annoying harmonic since changing the exhaust.

 

When I installed a set of Flowmaster 50 series mufflers on my car w/ the stock exhaust, I did have some resonance; when I had the dual exhaust install, it disappeared because, I think, the tips of the mufflers come out past the edge of the bumper now.

 

When the tone is such that it gives you a headache or nausea, you have resonance.

For some reason slims are more suceptible to a wider register of resonance. I know guys that ride in each others' cars all the time without a problem. The Gyno-Americans in their lives hate the sound. It gives them one of 'those' headaches.

 

res·o·nance
Pronunciation: \ˈre-zə-nən(t)s, ˈrez-nən(t)s\
Function: noun
Etymology: Middle English resonaunce, from Middle French resonance, from resoner to resound — more at resound
Date: 15th century
1 a: the quality or state of being resonant b (1): a vibration of large amplitude in a mechanical or electrical system caused by a relatively small periodic stimulus of the same or nearly the same period as the natural vibration period of the system (2): the state of adjustment that produces resonance in a mechanical or electrical system
2 a: the intensification and enriching of a musical tone by supplementary vibration b: a quality imparted to voiced sounds by vibration in anatomical resonating chambers or cavities (as the mouth or the nasal cavity) c: a quality of richness or variety d: a quality of evoking response <how much resonance the scandal seems to be having — United States News & World Report>
3: the sound elicited on percussion of the chest
4: the conceptual alternation of a chemical species (as a molecule or ion) between two or more equivalent allowed structural representations differing only in the placement of electrons that aids in understanding the actual state of the species as an amalgamation of its possible structures and the usually higher-than-expected stability of the species
5 a: the enhancement of an atomic, nuclear, or particle reaction or a scattering event by excitation of internal motion in the system b: magnetic resonance
6: an extremely short-lived elementary particle
7: a synchronous gravitational relationship of two celestial bodies (as moons) that orbit a third (as a planet) which can be expressed as a simple ratio of their orbital periods

 

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Of, or having no ability to summarize in own words. (see lame).
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Most every place that has sound reflection has resonance. It's caused by waves of sound energy adding on themselves to increase their volume. You might get things like ashtrays vibrating, but usually not.

For me, the easiest way to tell if you have resonance is have someone drive the car by you. If it sounds way louder inside than out, you've got some resonance. And, certain rpms will sound much louder than others. (It's not a gradual thing either. The sound level will gradual rise and fall as rpms near/leave the frequency of the cabin.)

But the real issue is whether the increasing volume near cabin resonance is annoying or not. Does it hamper speech? Does it interfer with listening of music? Does it make it harder to hear emergency vehicles? And, worse case... can it give you a headache over time?

To some resonance is good. It's music. Those are the same people who like ported stereo speakers. Other's like flat, pure sound. (I'm in between. It like added resonance, but at frequencies rediculously low... You know, the kind that causes earthquakes! )

gp

BTW: When you're just a tincy-bit above/below resonance, the pitch will oscillate as it "tries" to land on the note of natural cabin resonance.

 

O.K., I gotta ask... WTF is "Gyno-American"? And, is "slim" is skinny person or female?

 

females

 

Mine happens at around 2000-2200 rpm, and the whole cabin fills with the giant "OOOOMMMMMMM" sound

 

loud low pitched drone

 

I thought the oscillations in sound was resonance. As in 2 tuning forks struck at the same time sort of "pulse" sound.

I always thought of exhaust resonance in the context of either annoying droning or awesome dual engine cars.

 

Slim = Attractive female and/or the happy woman.
(Term coined on CFOT.)

Gyno-American is the grumpy woman whose attractiveness and relationship status is now irrelevant.
(Term coined by Al Bundy of 'Married With Children' fame while speaking to a crowd of ultra femminist man-haters.)

Both meant with a LOT of tongue in cheek innocent fun.

 

John, your exhaust was a little LOUD inside but walking behind it...

So I don't think it's the ole resonance deal, just loud exhaust that you can hear in the cabin...

 

Passing gas in a barrel.

 

So I guess it caught you off guard when I fired it.