hi, I also am using the 570dg and love it. I have a very cheap external
speaker from radio shack that came with an old general coverage receiver and
it helps a bit over using built in speaker in rig. Some people made me think
built in speaker was worse than it really is but it rough conditions an
external would help. Will probably just get the matching Kenwood speaker
eventually though a little expensive for what it is. Dave W4CI