My New Magnepan 1.7i's sound dull and lifeless on the top end...why?

1.7i's sound like they have a head cold because of where the inductor is placed in the crossover. 

If you don't want to mess with the insides, the easy solution is to buy a Shiit Loki or Lokius and bump the frequency you are not hearing properly. I bought one as an amusement and not only does it do that well, but you can also bump the bass, as they will produce a significant amount more than their stock configuration. Same concept as a plate amp for subs. Box subs don't go that low naturally, their bass is intentionally overdriven. Not talking about open baffle or horn subs, just boxed ones.

Let the naysayers descend like rabid wild animals while they mic measure their rooms and let a computer do the tampering for them, all feeling safe on the streets knowing there are no tone controls on their preamps.

Everything else that offers a significant performance increase is major surgery that requires removing the panty hose, starting with a million staples.

williethe53b is Back!  "rabid wild animals?" WTF?

I had the LRS for a while and liked them so much I stepped up to the 1.7i

I find they would run OK on a 25 watt tube pre/power amp (Cary Audio), a 50 watt tube integrated (Jolida), but they shine with big SS power (Adcom GFA-365 mono-blocks).

They sound great to me.  Placement is five feet (5') from the front wall, tweeters out, toe-in to aim just outside your ears.

Past speakers in the same room were KEF 104/2, Infinity RS II, Klipsch Chorus II.

PS - I can't hear above 13kHz....................................

Sounds strange. I bought my pair of 1.7i's about 2 years ago with never have seen or listened to a Magnepan in my life. I figured for that low dough it was worth taking a chance. Hooked them up to my Primaluna Dialogue Premium HP Integrated amp with KT-150'S and was blown away by the sound! Plenty of highs and mids. I also use AntiCable speaker wire and the stock jumpers. I run two subs from the single out on the Primaluna. Blows away the Vandersteen 3A Signatures that I replaced. Dana

All Magnepan speakers require a lively back wall to generate the proper sound at the listening position. If the back wall is too damped, it will muffle the high frequencies. Remove any damping panels, foam, etc from behind the speakers and listen. Maggies do not respond well to rooms extensively treated for cone speakers.