Commercial speakers are far different than typical speakers for the home. Most commercial speakers are 70V/100V, because they use a transformer between the amplifier and the speaker. Home speakers are 8 Ohm and require a home run to the amplifier via speaker cabling. Commercial speakers can be wired in series, greatly expanding the efficiency of installation and coverage. Commercial speakers have Taps on the transformer. This allows them to be optimized for the power output of the amplifier. Typically, you take the output of the amplifier and calculate 80% and then divide by the number of speakers in the circuit to set the taps correctly. Commercial ceiling speakers can provide very good coverage for background music, paging and program audio in conference rooms. The key to good coverage is quantity. If there are too few speakers, the sound will not be even and require more volume, which will result in more uneven sound. By incorporating the correct number of speakers, you can achieve good, even volume throughout the space.