Search for helmholtz resonators..
Most well designed intake manifolds add some sort of resonance affect for certain rpm ranges. The more advanced intakes, such as on the KLDE/KLZE have multiple paths which help. The F2 resonance chamber is fairly simple, and relatively effective.
Subaru uses them extensively for noise reduction.
some linkage:
Helmholtz Resonator - DiracDelta Science & Engineering Encyclopedia
Intake Manifold Tech: Runner Size Calculations - Team Integra
Outlaw Power - Intake System Technology
Soarer - The Intake Resonator
FLUID DYNAMIC STUDY OF INTAKE MANIFOLDS OF INTERNAL COMBUSTION ENGINES IN PRESENCE OF ACOUSTIC RESONATORS
Thunder Products - Performance carburetor and clutching for snowmobiles, motorcycles and ATVs.
FTLRacing
Still Air Box Design for tuned engines
Intake Theory
The ideal situation would be to have a system which allows for rpm and load variation of the length of the intake manifold ports, variable volume intake manifold, and a variable sized helmholtz resonator...
BUT.. most people settle for just variable lenght intake runners, that's tough enough.
See:
http://www.mx6.com/forums/fe-dohc/20...hidden-us.html (ITB NA FE3 Miata/MX5 thread hidden from us! ;-))