If pianos covered 10 octaves, the range from 16 to 20Khz would be the last 3 white keys. (not a lot)

If being close to a TV set still bothers you, thats 15Khz. the hetrodyne squeal from behind the picture tube actually hurt my ears when I was young. It quit bothering me after 3 or 4 concerts. If a TV squealing doesn't bother you, I would say your acuity there is getting low and I wouldn't worry about the last half of the top octave too much. You aint gettin' it tweeters or not. There is something to be said for that air up there. If I play real loud I can still hear it, but it isn't pretty from most mass production recordings and players, so I can live without it.

Reviews and advertisements can make us feel like we all have the ears of a bat. If you are young you might, but if you have been to a few loud clubs or concerts, slammin' car systems, drove the highway with windows down often or worked any place louder than Kinkos, you are probably already losing a bit off the top. Americans adults who hear decent at 20KHz are seriously in the minority.

Oh! I have owned and sold a lot of nice speakers. I put hopped up Acoustats in the closet to make room for the Pi's.
Thomas