When the PS1400 and PT800 are docked, the SYSTEM INPUT speaker connectors are used, and the LF CROSSOVER switch is in the NORMAL position. It's a four-way speaker, with LF levels controlled by the LF LEVEL dial, not the LFE LEVEL dial.
If the PS1400 is used as a pure sub, the LFE/SUBWOOFER INPUT is used, and the LFE LEVEL controls LFE level. In this case, the LF CROSSOVER is in the SEPARATED position. You can choose to do this even when the units are docked, but basically you've got a three-way with a frequency response of 80Hz–22kHz and an LFE sub. Also in this case, your receiver or pre/pro better be able to cross everything from 80Hz down away from the PT800s or you'll be in trouble. The problem with this approach is that with two-channel music on some receivers and pre/pros you're not going to have the LFE active, so your stereo experience might be somewhat disappointing.
OTOH, having them stacked and NORMAL gives you a great stereo experience in part because the LE14H-3 is crossing over at 130Hz, not 80Hz as you might otherwise set it up with your receiver or pre/pro. However, the LFE isn't everything you want it to be for movies, because the LFE material isn't going to a separate sub.
So my solution in this case is to have the FL and FR Performance stacks running as four-way speakers, like L250s (or L7s or XPL200s), plus a PS1400 running as a dedicated LFE subwoofer. I really want to get one more PS1400 to run in that fashion. (Harman
mulitsubs, you know.
)
There is a kind of hybrid of these two approaches that JBL documents in the OM, but I haven't really tried it yet.
So if I prefer a four-way system for two channel listening over a three-way and a sub, is it inevitable that I feel the same way about a two-way and a sub?
For comparison, I've got a pair of 4430s that make some very nice two-channel music, as well as SVA2100s, SVA1800s, and L60Ts. Starting with the L60Ts, with their 8" woofers, there's no doubt they need help with the low end, just like the PT800s do. So even for two-channel listening in my Watts office, they get augmented with a 12" sub.
The SVAs are more powerful than the L60Ts could ever hope to be, but being able to make more sound doesn't translate into a wider range of sound, at least not for the SVA1800s. A nice FA CSS200 THX sub with an LE120H-1 inside helps these guys get to the bottom better. The SVA2100s can sound pretty convincing w/o a sub, but at 10", the woofers still don't have that capability that adding a couple of LE12H-1 based subs brings.
Now, the 4430s with their 2235H 15" boomers should be fine, right? Well, they are fine, except the 2235Hs are covering a lot of ground, and I was a bit disappointed in the quality of the low bass with these speakers. When I sort of stumbled into ownership of a B380 and BX63A and added it to this combo, the sound improved a lot, and the low end got a much better.
I truly feel that the Performance Series offers the best of both worlds, especially if you can have both stacks and separate subs. For me, even the four-way PS stacks are preferable to some pretty nice two-way systems when it's time for two-channel music, even when you augment those two-ways with a sub or two.
JMO, of course.