SP-21 Speaker Base-station loudspeaker The Icom SP-21 speaker matches many Icom receivers and transceivers. It is 8 ohms and handles up to 3 watts. The SP-21 has a snap-out tilt bar to raise the front of the speaker if desired. Black metal construction 5.25 x 4.25 x 11 inches. A wired-in audio cable, terminating in a 1/8 inch mini plug is featured.