Yes. Here's the general approach.
1) In REW, measure the frequency response from each sub to each listening position using the REW acoustic timing reference feature. For N subs at M listening positions, that will be N * M measurements. Make sure all the filters in the miniDSP are cleared out, including disabling the crossover, and setting delays to 0 and attenuation to 0 dB before measuring. See the
measurements page of the MSO manual for detailed instructions on doing the measurements.
2) Export each of the measurements from REW as a text file using File, Export, Export measurement as text in REW. Use a .FRD extension for ease of use (it's the default extension for MSO file import), and limit the upper frequency value of the exported files to no larger than 400 Hz so the files are not too large and import into MSO quickly.
3) Import the measurement text files into MSO.
4) Set up your project similarly to how it's done in the tutorial, but use only PEQ filters, gain blocks and delay blocks in the sub channels you define. Start with 4 PEQ filters per channel. Don't use any low-pass filters. The tutorial uses low-pass filters, but it was set up to use the Geddes approach, which is unusual in that it avoids using the AVR crossover. You'll be using the low-pass filters that are built into your AVR.
5) Try running an optimization.
6) If you aren't satisfied with the results of the optimization, try different things and/or ask here for help.
7) Once you are satisfied with your optimization results, for each subwoofer channel in MSO, export a biquad text file. For N independently-controlled subs, that will be N biquad files. Keep track of which one belongs with which sub (and miniDSP channel).
8) Import each appropriate biquad text file into the correct output filter channel of the miniDSP. This is described in the 2x4 HD manual in the "Parametric EQ file import (REW integration)" section. This will set up all the filters in each channel in one shot. It doesn't set up attenuation or delay though.
9) Manually set the individual miniDSP channel delay and attenuation as specified in MSO for each miniDSP output channel.
10) Set the AVR sub distance and trim value as specified in the MSO filter report for the configuration.
11) After you're done, it's a good idea to measure your system with all the subs energized at once, for at least one listening position. You can export these measurements as text, then import them into MSO using MSO's File, Import Plot-Only Measurements command. You can then plot these measurements on the same graph as MSO's predictions, allowing for easy comparison. The measured results should agree with MSO's prediction very closely. If the don't, then something is wrong and that problem must be chased down.
