I suspect the audio industry, like many others, and Harley-Davidson comes to mind, are finding the baby boom generation has passed the peak years of spending. As a member of that group, I can say I've accumulated most of what I need/want, and will not be a great customer in the future. The generations coming behind the boomers are smaller, poorer (?) and have different tastes. The book Boom Bust Echo was a good read on this subject.
More potential bad news for some big names...