Yep, 1 volt in will give you 1V out. If you don't change the gains inside, it is unity gain (no change)

Of course once you start dividing up the spectrum, each output is now a fraction of the full spectrum and thus lower in level. That will be very dependent on signal and crossover points, of course. Driving the DCX with a hot input helps keep the signal up out of the noise floor. The noise floor has been a big problem for folks using the DCX straight into power amps with no attenuation.

It really was not designed to be used that way - that's its major drawback for home Hi-Fi use.