A mixing assembly for an exhaust system can include an outer body, a front plate, a back plate, a middle member, and an inner member. The outer body defines an interior volume and has a center axis. The front plate defines an upstream portion of the interior volume and the back plate defines a downstream portion of the interior volume. The middle member is positioned transverse to the center axis and defines a volume. The inner member is positioned coaxially with the middle member inside the middle member. The front plate includes inlets configured to direct exhaust to (i) a first flow path into an interior of the inner member, (ii) a second flow path into the volume of the middle member between a sidewall of the middle member and a sidewall of the inner member, and (iii) a third flow path into the interior volume of the outer body.