After lusting over 710, 810, 910, 980, 1290, etc. for over 10 years, I finally got around to pulling the trigger a couple weeks ago on a pair of L980s I had a lead on for a few months. For the past couple days, I was adding my impressions to an old thread on AK, then asked about the biamp feature. That's probably not the target audience there, so I figured I'd post here, likely to get a more accurate and comprehensive response.
I've read just about every thread I could find on the biamping feature of these larger ADS models, and there is not an overwhelming consensus one way or the other.
I have become confused by reading reports from those who say they added an electronic crossover (dbx/Rane/Ashley/etc.) and the speakers woke up. Others have said adding the electronic crossover ruined the speaker's balance, sounding awful, and they went back to stock full range inputs.
What I came away with from all these threads, is that the E-crossover is a deal-breaker for technical reasons, due to the slope imbalance that results on the high pass circuit. For example, the stock slope is 12 dB for both high and low pass. Adding a 12 dB E-crossover adds another 12 (or whatever its designed slope is) to the high pass circuit, but the woofer is only using the e-crossover's 12 or whatever dB, and that affects how the woofer to mid crossover point blends.
For those who love the sound of biamping these, do you not hear that technical imbalance? Is it not audible to human ears? Most of those opposed to the e-crossover say it is audible. Are we splitting hairs again as we so often do?