You can't just add "db's" together. If you could then if you had 2 cabinets that each one could do 130dB-then you would be able to produce 260dB. NOT QUITE!
I have no opinion about the LMS-so don't ask.
But let's say for argument that you can get a 4dB increase. Then by replacing ALL of the drivers in the same number of cabinets-you would net a 4dB increase-TOTAL.
Since each cabinet would have a "realative" difference of 4dB-then ALL the cabinets would have the same relative difference-4dB.
As a side-there are A LOT of factors that go into driver choice-cabinet shape/size etc. Everything is a matter of compromise. For example we have had to currently (hopefully not forever) discontinue our TH50-because the driver manufacturer would no longer make the driver. It was expensive-large and heavy. It was discontinued because not enough people were buying them.
Like- for example-I wonder how many people would not have bought the DTS10 kits if they were twice as expensive? (I don't know the relative difference in price of the drivers-just throwing a number out there).
For some people it is all about ultimate performance-for others it is about economy of realistic performance. And for others it is all about cheap.
If you want the "ultimate" then just buy a Danley Matterhorn and back it up to your house. OH-NOW money and size start to be an issue???????
What is expensive for some people is not expensive for others. What is just OK performance for some people is spectacular for others-it just depends.
See there ARE limitations