In regard to mixing sealed and ported cabs.. I found a great post by the Master Himself .. Jim B.
From another thread.
From a pure technical stand point, given the 2 different roll off rates of the 2 designs in the low end (12db/octave - sealed vs. 24db/octave -ported) at some point down lower in their responses, there's going to be a gradual phase shift towards 90 degrees between the two. This, however, would be very low in frequency, typically below 40hz (based on the designs of the cabs in question) and it will be a gradual transition starting about an octave or so above this frequency. So what does this mean? The good news is they're still in phase with each other, but will only have a sum of 3db (90deg phase shift) vs. 6db (in phase)down low. But also given the sealed cabinet is rolling off half as fast, which means it will be higher in level when the phase shift is approaching 90 degrees between the 2 designs, it will most likely be a wash vs. 2 ported cabs whose responses are lower in level due to the steeper roll off rate(are you glad you asked yet? ;-} ).
The main reason I shy away from recommending these type of sealed/ported combos is mostly due to the typical sensitivity differences of the 2 designs. Sealed cabinets of a given size and configuration tend to be a good 3db less sensitive than a ported cab of similar size and configuration based on the type of woofers used in each design, which means the ported cab will tend to dominate the tonal spectrum of the mix of the 2 cabs. But that doesn't mean the additive characteristics of the 2 cabs are not desirable. That's up to the user. And BTW, this carries into also mixing cabs of the same design which have a 3db or more delta in sensitivity between the 2 cabs. In another thread (or maybe this thread) someone asked about mixing our NV115 with our NV212T. They're both sealed but I responded saying the NV212T will dominate the sound to a point you don't even realize the NV115 is there, until you disconnect the NV115 and realize it is making a contribution, it's just not calling any attention to itself.
In the case of our HG310, for instance, mixed with our HDN210, they use the same woofers and therefore it's really not an issue as described above from a tonal mix perspective. Same I believe would be for the HG410 and and HDN210's, as they also all use the same woofers and the mix would be cumulative.
Bottom line, if it sounds good and works for you, go for it!;-}