I've been running my Lsi9s with upgraded crossovers for a few weeks now. I think many here are familiar with Ben's work; for those who are not:
the standard package is replacement of the original caps with Sonicaps (highs) and Daytons (lows) as well as Mills resistors. This is what I had him do for me.
After a flurry of upgrades in 2008 and the first half of 2009, my economic situation of late dictates that I could probably afford only one audio purchase/upgrade this year. I decided on the speaker crossover upgrade and I don't regret it one bit.
Night and day difference? Yes and no. I think it comes down to two sets of variables. 1) Quality of recording and 2) type of music. I notice a huge improvement on good to excellent recorded CDs (I don't spin vinyl). With these, yes, I would say night and day difference. On dull and flat sounding recordings there is not much of a difference at all. They don't sound worse (as I have a pretty neutral source) but just not really better (the mantra 'garbage in, garbage out' rings truer and truer). Second, I notice the biggest improvement in hard rock (Zeppelin), rap/hip-hop (Beastie Boys, Eminem, The Roots) and electronica (Animal Collective). I've always thought these speakers handled jazz and soft/acoustic music (i.e. early Elliott Smith, Bon Iver) with excellence (and they still do)...probably classical too but I'm not there yet. But I never would have guessed that I'd equally enjoy listening to these other genres on this system.
I'm also a little surprised at my initial findings -- since Sonicaps seem to have a slightly better reputation than Daytons (no?) I am surprised to find that for me what sticks out most on the musical spectrum is the improvement on the low end. In particular, the snare drums, bass and lower tones of piano just have this really rich, life-like presentation. Much more heft and weight than before. (A drum solo at the end of the 3rd song on Fiona Apple's When the Pawn just blows me away now, for example). I might just need some more time to evaluate the highs.
After playing one of my wife's CDs (HDCD) for her, I asked her if she noticed a difference. She described the sound as much more "3D" than before -- she has a very good ear, having taken piano lessons for several years, but might lack the vocabulary typically used in audio forums...moreover she's not a native English speaker -- but I think what she was getting at was improved imaging. The sounds of the various instruments (and voice) just sort of leap out at you with a vibrancy that wasn't as obvious prior to the upgrade. Again, I should mention that this was a very nice recording.
In short, I loved the musicality of the Lsi9s to begin with. Thats why I didn't really consider selling these and moving on to something else. I feel this upgrade (at least for me in my system) has allowed me to retain all of the strong features of the speakers while at also enabling them to handle other kinds of music very well, making them an even more versatile speaker.
Where to go from here? Who knows but I can tell you one thing for sure...when I do have the ability to upgrade again, it will NOT have anything to do with speakers.
Oh, and great job Ben!