An air resonator system for a vehicle has a variable volume to reduce noise expected at both high and low speeds. In one embodiment, a pair of necks (28, 32) communicate with chamber portions (30, 31). A valve (38) selectively blocks communication between the chamber portions (30, 31) and allows each of the necks to communicate with the relatively small volume chamber portions. This position is particularly good for reducing the high frequency noise expected at high engine speeds. The valve (38) is movable to a second position at which it allows communication between the two chamber portions and blocks communication between one of the necks and its respective chamber portion. The relatively large chamber volume provided at this position is particularly well suited for reducing the low frequency noise expected with low engine speed. Thus, a single air resonator system is provided which can be adjusted to accommodate noise at both high and low speeds.