Jamo C93 Satin Black (Pr.) Bookshelf Speakers 1inch (25 mm) silk dome decoupled tweeter with AntiDiffraction WaveGuide and Tweeter Distortion Reduction 6inch (152 mm) Hybrid Composition Conical Cone woofer with Long Displacement Surround technology. AntiDiffraction Waveguide (ADW): Provides improved offaxis response with more uniform high frequency extension. Hybrid Composition Conical Cone (HCCC): Provides the stiffness and strength of aluminum or titanium, with the transient response and smoothness of wood fibre. Tweeter Distortion Reduction (TDR): Provides lower distortion, greater high frequency extension and smoother high end.