A 1.5uF cap against an 8 ohm driver would set the XO point at about 13KHz, which like Wayne said, is quite high. Nevertheless, signal would only be approx 17 or 18dB down at the recommended XO point of 2500Hz which does not seem to be enough to protect the driver.Also, doesn't attaching the cap directly to the driver make it difficult to properly implement an L-pad? Typically, L-pad sits between XO and driver.