The B&W CCM664 are one of the most popular choices for 6" in ceiling speakers. You can go larger and get 8" drive units, but if your room is small to medium in size you won't need the extra couple of inches as all this adds is more weight. In some installations, it may actually be better to use two pairs of these smaller speakers than a single pair of 8" drive units. Use them on their own for stereo music, or as part of a discrete home cinema system.
We've installed these in a wide range of different homes and these speakers work best in medium to small spaces, or as part of a 'chain' of 6" speakers in a larger room. If you have a very small space (such as a dressing room or bathroom) it may be worth looking at the 6" SR range which features twin tweeters within a single speaker cabinet to give you stereo effect from one speaker.
These speakers are mid placed in the B&W range, and as such they have great quality but not necessarily the high price tag of the top end speakers. We think either these or the CCM663 speakers are perfect for most people as you don't miss out on much and still get the great B&W sound. The speaker features a 6in bass/midrange driver with a Nautilus swirl-loaded 1in aluminium dome tweeter that pivots for adjustable off-axis treble response.
The speaker comes with a round grille as standard, but you can add the optional 66 grille to your speaker to transform it into a square speaker.