I own the Polk LSi 9's as the front mains in my little HT (little as in a converted 11x13 bedroom)
The 9's are great speakers, and yes there is a decent low end to the speakers. (I tried the speakers set at large with the sub filter set at 60Hz and the sub disconnected). The beach scene in Saving Private Ryan is still going to get your attention, but there is something lacking..... oh shucks, I know what it is ..... it is bass. The bass is there, it just doesn't have any humpf to it.... no visceral impact. Add a sub and it is a whole new (scary) world.
My musical tastes do not include a lot of acoustical works (with the exception of Carly Simon and good ole Barbara Streisand), so I am may not be a good judge of the speakers regarding music. On Carly's "Anticipation" the bass is there, it just lacks definition or impact. Comparatively the bass is about the same as those stock 6" woofers in the car doors of my old econo car. It is there, but not really there.
This lack of definitive Low End is the weak point of all bookshelf speakers. A 6" woofer is just not going to move a lot of air. But bookshelf speakers can be more easily placed in a room, which is important in small rooms (such as mine) or for WAF.
As negative as I have been about the LSi 9's without a sub, as free standing, WAF acceptable speakers the LSi 9's will work. The dual 6" woofer design (one woofer and one rolled off at 200hz for a midrange) is going to work well on voice and light music. Play something like "Field of Dreams" or "Shrek" and you will most likely be happy with the speakers by themselves without a sub. I had "Wall Steet" playing for the entire movie with the sub disconnected and never noticed. Next movie on the play list was "Ronin" and yes I did notice the lack of the sub .... at the opening menu of the movie.
Polk does have a little $200 sub that would work well to round off the bottom end of the speakers. The plus side is that the sub is small, the bass output is not tremendous, and WAF demands can be met.
For comparison sake, adding the small sub would be the same as adding 6" speakers to the rear deck of my old econo car. The bass may not have been earth shattering, but finally I could feel some of the bass. Just what Carly is "Anticipating"
My suggestion is to try the Polk LSi 9's at Tweeters and insist the subs be turned off.
