I am asusming that your paging system is conndcted to the RCA on the processor.
DKT would be your Toshiba phones and SLT would be analog phones.
One thing to think about is the PAD table is like a muffler, the higher the value the lower the volume.
Off the top of my head, I don't recall adjust the volume for a paging system. Usually I just turn down the amp a little bit.