Audio Control makes good stuff at reasonable cost. In particular, their "Richter Scale" equalizer/analyser covers the range below 150 Hz, (which is probably where you need it) and includes a crossover should you wish to biamp, or subwoof.
Analog Domain EQs
Anyone have any recommendations regarding equalizers that fully operate in the analog domain? I'm looking to do some room correction, but I don't want a digital component in my tubed-component chain. Ideally, the unit would have single ended inputs (as my system doesn't have XLR connections and I would prefer not to use RCA-XLR converters).