sub flapping sound

  1. J

    Sub flapping sound

    So I have my two alpine type r 12 in a ported box under my back seat with 1.70 cubic feet of air space per side tuned to 36 hertz and I'm having this weird sound comin from the port like a flapping sound it sounds like I put a piece of paper in front of the vent it's not too noticeable but on...