Patent ID: 8897477

Claim:
A dual resonator chamber with variable volume, comprising: a first housing having a first upper wall, at least one first sidewall and a first lower end, the first lower end being adapted for mounting on a support surface and having a first opening formed therethrough, the first housing having a first inner neck portion internally mounted on the first lower end about the first opening and projecting upwardly therefrom, the first housing being hollow and having an interior; a second housing having a second upper wall, at least one second sidewall and a second lower end, the second lower end having a second opening formed therethrough, the second housing having a second inner neck portion internally mounted on the second lower end about the second opening and projecting upwardly therefrom, the second housing being slidably mounted within the first housing such that the second inner neck portion of the second housing is slidably mounted about the first inner neck portion of the first housing, the second housing being hollow and having an interior; a sliding wall slidably mounted within the second housing, the sliding wall dividing the interior of the second housing into upper and lower resonator chambers, the sliding wall having a passage formed therethrough; means for selectively adjusting the height of the sliding wall with respect to the second lower end of the second housing to selectively adjust volumes of the upper and lower resonator chambers; and means for selectively adjusting the height of the second lower end of the second housing with respect to the first lower end of the first housing to selectively adjust a neck length of the lower resonator chamber.