To help you a little, your spacing/dimension/size numbers are confusing without knowing if you are giving us the correct value, to compound the confusion work in generic units not cm. When giving “Size” the param “Spacing” is meaningless, only when you give the grid “Width/Length/Height - Dimensions” does the “Spacing” param come into play.
Assuming “Size” is the actual size that is a pretty dense grid. At a 618x630x678 you are looking at some Ram allocation roughly of 12gb per frame (less all your other system requirements, Max itself, and whatever other programs you have running) So if on a win7/10 machine I would guess you are going to peak around 18-22gb usage during the sim (just a guess).
This workflow can be confusing, in Wavelet the “Grid Detail Scale” param is a multiplier, were as “Spacing” its associated value in the base sim is a divisor.
So by performing a Wavelet pass on that “Size” you are looking to multiply you current density by 2.2. You are squaring you’re density giving you final a “Size” of 1360x1386x1492. Your ram requirement will exceed 120+gb in its peak frame usage. By my guess you won’t even have enough ram to Render a frame let alone simulate it.
The best solution is too buy more ram, as you obviously want to achieve a level of detail beyond your machine capabilities 
Apart from that decreasing the density of your wavelet sim will bring down the required amount of memory. You are going to be able to get much more out of it in your current build. In all honesty you should get as high a detail sim as you can out of the initial sim and forget Wavelet or decrease your base simulation by half then try a Wavelet.
