14,8 cm Waveguide of high-quality plastic for 25 mm tweeters. The exponential enlargement provides a high sound pressure level gain in the lower high frequency range, which discharges the tweeter. In addition, the focus and the coupling to a woofer are improved, because the sound generation planes move closer together. For fixation of the tweeter on the waveguide 4 pieces M4 screws (length approx. 10 mm) are added.