Radio Shack only had 100 micro henry inductors. If I'd gone to an industrial electronic store I could have found more. So I placed one in series with each speaker and it worked. The tinny sound was reduced but not eliminated, and the bass was boosted even further. I had the loudness enabled, which seemed to do better drowning out the tinniness. When I turned off loudness, I got real good midrange, acceptable treble, and still plenty of bass. The treble was still turned all the way down, though. I estimate a 500 micro henry inductor would work best, since that would allow treble at other than minimum on the control. I may mail order some.
-- dgm