To clarify why this question doesn't make sense, you cannot attract waves. You can reflect them, emit them, absorb them or in some ways focus them. It's the same as with compression waves in air (sound) or waves in water, have you ever seen a ripple in water curve toward something? You can channel a wave with a wave guide, but again, this isn't attracting it, it's channeling it (essentially, reflecting any waves that go off a path so they tend to continue on that path). One might mistake that a parabolic dish antenna "attracts waves" but it is really just reflecting waves that happen to hit the dish into a common point, focusing them. The total wave energy that it can pick up will never exceed the amount that would have passed through surface of space occupied by that of the antenna.
That is of course unless you can find a way to bend space, or spacetime. Which is the reason for the black hole comment above.