I was cruising a 2010-2011 Camaro Forum and ran across a member who used 2 Helmholtz Resonators in his exhaust to help with drone on the highway and at a certain RPM.

I don't know too much about Helmholtz Resonators but I do know the following.
They are basicly a pipe selded onto the exhaust system which is then dead ended.
"They act as a place for certain resonance waves to go and die".
They use exhaust resonance to help build a broader power band and cut down on drone.
They need to be tuned to the specific rpm you want the drone to go away and specific to your car and motor modifications.
They are used inside OEM muffler designs such as the L99 2010 Camaro.
They are used on 2-stroke motors and are very common.
They can sometimes cause high rpm resistance which needs to be considered when designing them.
Some people have used them with an Electronic cutout to help quiet an exhaust when daily driving, then they close the cutout for track days.






Any ideas on using one on our horrible sounding LSJ's with 3 Inch Exhausts?

 

looks like it would slow down the velocity because of the disruption in airflow.

 

Looks exactly like the resonators in stock intake systems. As far as the horrible LSJ sound goes get a 2.8 pulley and floor it for serious blower whine