Sweet sound, sweet price. 1-in. silk-dome tweeters give the in-ceiling Proficient® Audio C621 an especially sweet and detailed sound, ideal for those who seek a higher level of musical truth. The tweeter pivots so you can direct the sound wherever you need it. The tough 6-1/2-in. polypropylene-cone woofers play down to 45 Hz - as deep as some big tower speakers can play. With 91-dB sensitivity, the C621 speaker pair puts out an incredible amount of sound from even a 10-watt amplifier. It has an 8-ohm nominal impedance, which makes it easy to drive with any amp you might want to use. For your convenience, it uses the same cutout template and sturdy dogleg mounting system as all of our other 6-1/2 in. ceiling speakers. The speaker pair includes thin-bezel grilles held by neo magnets.