All the recircs I've tested have light springs in them. They don't get weak, they start weak. They are all open under idle conditions and in effect allow air to bypass the turbos under light load conditions. When the turbos begin to boost (higher than "light load condition") and the manifold pressure approaches atmospheric they begin to close and that's when the Goose Honk occurs.
Maybe you just have "tuned" ears to hear the honk with the airbox installed.
