Mogwai 'Atomic' (2016-2LP "Nuclear Sun" orange vinyl)
Saw them perform this live alongside the documentary on Sunday night at the Edinburgh Playhouse. Awesome music/performance & an excellent, although at times quite harrowing film. Still, a most enjoyable ( if not cheery ) way to celebrate the big 5 O
Yes, that'll work fine as a starting point. What you may find, however, is that the noise (hiss) may become noticeable as the Signal-noise ratio of the DCX will be measured relative to a +24dB output, and so probably around 20dB higher than your power amps need for full output. This will make the S/N ratio 20dB worse than it need be. I ended up with 16dB attenuators in the cables between the DCX output and the power amp inputs. Bear in mind also that as there's no passive crossover, any hiss coming from the power amps themselves will not be attenuated by any crossover, so will be present in each driver, so it's a good idea to use power amps that have particularly low hum and hiss if you're using sensitive drivers.
However, you can't attenuate the input of the power amps too much, as then your pre-amp will struggle to drive the DCX fully before the preamp clips. Fortunately, the DCX has very good gain adjustments on the input and outputs in DSP, so matching is not too difficult.
The message from all this is for an active system to work, the gain, headroom and noise through the whole system, from input right through to loudspeaker output has to be correctly ranged so that the individual stages all work at their optimum level, without wasting headroom, or risking early clipping.
Anyway, that's all for further down the road. What you're proposing is a good way to start.
it's quite easy to do an initial setup. The confusing bit is on the outputs, 1 left low, 2 left hi, 3 left low, 4 left hi
you can then adjust each output to crossover the bads/mid to your tweeters.
After reading Serge's advice I've now added 11 dB of gain on the inputs and then got -11 dB on the outputs still letting the preamp control the overall volume. The increase in detail from a 0 dB gain on the inputs is quite noticeable .