It appears that the 1056B03 doesn't have a setup code for Sony Active Speakers. And it can't be manually programmed with the 994 command like some cable remotes, including the 1056B01 and other previous Atlas remotes. But previous versions also had setup code Audio 0689, which sends the correct signals.
So, either use a different remote or spend $10 to get a USB to serial cable, and use the RMIR software to program your 1056B03. Example cable, make sure you get FTDI chipset
. Cheaper ones are available from CHina, but the shipping takes a long time.