Frequency Range - Bookshelf Speakers

I've tried, TRIED, I tell you! ... to properly integrate a sub with bookshelf speakers. In my experience (for what that's worth... not much), you don't want a monitor going lower than around 60hz or you start messing with serious room modes, etc. around the speaker/sub crossover and it's near impossible to get a good result.

The best scenario I've found is to get some good monitors that go reasonably deep and forget the sub; unless you're a fan of pipe-organ music, of course. Deep isn't the only criteria - they must go deep enough (~45hz) and be articulate in that region.

The Usher X-718's (-3db @ 42hz) I currently run fit this bill exactly and I don't miss the sub at all with rock nor jazz.

Acoustat6 - wow, took me a minute to figure out what you were talking about! FYI - for anyone else, the quote Acoustat6 attributes to me is from an old post unrelated to this one.

The short answer is that I've never really had any problems with subsonics and rumble. In fact, the phono preamp I now use (PS Audio GCPH) has built in subsonic filtering so I don't even think about it. The old post you quote was simply me "thinking out loud" and curious.

That being said, I've found there is rarely much musical information below around 40hz unless, as I originally stated, you're a pipe-organ fan.

In measuring in my room, I found that introducing a sub impacted other areas of the musical spectrum in a negative way even when I had it crossed over in the 30hz range. I simply could never get good results. I'm not saying others may not be able to in their rooms, just simply speaking from experience in a small squarish room.