I probably should have said it is not ideal to run two full range cabinets and Stevie aims for a no compromise approach.
Phil has explained better than I could, but if we ignore the issues Phil mentions, there are real benefits for the DIY builder.
These are weight, not using the compression driver and horn saves about 0.5Kg or over one pound weight.
Secondly, cost. A good comp driver and horn with cost £70+.
Two commercial cabinets may sound great but as we are building ourselves, the cost and weight saving make it more than worthwhile,