Correct me if I’m wrong, but I would say the OP needs to clarify what he means by ’active’ subwoofers. Does that mean ’powered’ with their own amps inside, or actually simply ’active’ like any other speaker, or, non-passive.
If they are actually ’powered’. I don’t think it would matter how you hooked them up, as the subs internal amp will take the incoming signal and power that sub. Thus, I cannot see how you could change the volume with a preamp or integrated without a dedicated sub out/LFE volume control option.
If they are truly ’active’ subs, then yea, I guess you should/could be able to control their volume/gain separately with a preamp or integrated depending on out options.
@oldhvymec I just recently decommissioned my ZPre3, as I just ’stepped up’ in the world of preamps. Great little pre though, served me wonderfully. It, the Zpre3, has a single sub out, and also a mono out. I think both are fixed. And, no seperate sub volume control on that pre. I think you have to get up to the New 200 series to get that. It also has both R/L fixed and variable control outs.