I picked up a nice pair of XPL140A's today, (craigslist, and no joke - they were replacing them with Bose!). They're black lacquer, ('perfectly match my XPL200a's!), in *mint* condition, (other than 2 broken grille pegs), stands included, but I'm a little confused about the hookup.
I've posted the schematic below, and as can be seen, there are no internal connections between the LF and MF/HF sections, and there are also separate external +/- connectors. But unlike the XPL200A's, there's no bi-amp switch, and these are also missing the little plates that connect the LF and MF/HF sections - I'm assuming the sellers were connecting the amp leads across both sections.
For plain stereo operation, hooking up both sections to the same speaker cable is normal, correct? (Anyone have a spare set of strapping bars?) But without a bi-amp switch, are these somehow still bi-ampable? If so, I assume an electronic crossover is still needed, or can I simply run one amp to the LF and another to the MF/HF? (Like I mentioned in another thread, I'm no electronics expert when it comes to crossovers. )
OK - I just downloaded the manual from JBL, and I see they show both bi-wire and "bi-amp" operation. This is in the second pic. It looks like I'd still need an active crossover for true bi-amp, since without one, I'd still be sending full frequencies to both the LF and MF/HF sections of the internal crossovers. And with the internal crossovers in such a circuit, wouldn't there be an additive effect of the crossovers if an active crossover were still used??
I haven't hooked them up yet, but without an active crossover ahead of the amps, I don't see a real sonic advantage to using 4 amps, since all speaker leads would be carrying the same frequencies.
Am I missing something here? With the internal crossovers, is it technically a bad idea to run an active crossover for true bi-amping?
'Any suggestions much appreciated!
Also - a couple pics of the units at the end.
Thanks - John