Niles FG01151 HDLCR In-Wall LCR High Definition Loudspeaker Dual 5-1/4" Injection-molded TCC (talc, Carbon, And Ceramic-filled) Polypropylene Woofers Offer Extreme Rigidity To Reduce Breakup And Lower Distortion Long-throw Voice Coil/magnet Structure Increases Cone Excursion To Enhance Low Frequency Response And Dynamic Impact 1" Teteron Dome Tweeter Is Fluid Cooled And Delivers Ultra-wide Dispersion To Reproduce Clear And Detailed High Frequencies Proprietary Tweeter-adjustment Mechanism Ratchets In 1mm Increments And Then Pivots For Precise Aiming Of High Frequencies Bass And Treble Controls Enable Precise Tone Matching In Any Room