Bill, PrE10 sorry about dual entry - 1st time mistake.
Don't worry about the duplicate post. It happens, and at the MOD's have the tools to handle that. I think that Steve has already deleted that duplicate. What happens with a duplicate post is that some responders will Reply to one, and some to the other. Then, the OP has to mentally combine the answers. Unfortunately, there is no way for a MOD to "combine" posts - only Edit, Delete, and Branch (separate) a post.
As to the question, in PrE 10 (actually most versions prior to PrE 11), what happens if you go to Window, in the Toolbar. Does Audio Mixer not show in the drop-down?