The ceiling speaker with extra kick. The Proficient® Audio C641’s grille conceals tone switches that let you boost the bass and/or treble by 3 decibels. With the flick of a switch, you can kick up the lows or highs to suit your taste. No matter how you set the switches, you’ll love the C641’s sound, thanks to its low-distortion graphite woofer and aluminum tweeter. No subwoofer needed here, because the C641 plays down to 32 Hz. That’s 9 Hz below the deepest note on an upright bass! The 92 dB sensitivity means the C641 needs only about one-third as much power as a typical speaker, so you can get satisfying sound even with very low-powered amplifiers. A sturdy dogleg mounting system makes it easy to install. This speaker pair includes thin-bezel grilles held by neo magnets.