Icom SP-23 Base Speaker with Filtration. Order #1696 List Price: $330.00 Your Price: $239.95. The Icom SP-23 speaker matches many Icom receivers and transceivers. It is 8 ohms and is rated at 2 watts [4 watts maximum]. The SP-23 has four separate audio network filters [HPF1 500 Hz, HPF2 250 This forum message list include all message for that is related to SP-23, this include message that also is related to articles. If the message is relate to an article, the article can be selected next to each message.