Hi Graciesmom,
[quote]This time I would like to replace the topper with the best memory foam I can buy and combine it with a layer of latex. Perhaps 2 inches of sensus and 2 inch of latex. I want the quick sand feel but also support. My coil bed is supportive but I realized from past experience that too much memory foam isn’t a good thing, as it can cause posture problems. This was the case when I first received the 4 inch sensus as I sunk in too far before I bottomed out.
The question remains do I put e latex over the memory foam or vise versa and is a 2 :2 a good topper ratio?[/quote]
This is really a matter of personal preference and would be up to each person to decide which they preferred. As an example, I like this type of layering and my own personal preference would be to have the latex over the memory foam because I don’t particularly like the “quicksand” feeling and much prefer a more “on” the mattress, resilient, and “movement friendly” feel. It sounds though like your preferences are different than mine (and more in line with the more “typical” order of latex and memory foam layering) and you would likely do better with the memory foam on top. With only 2" of memory foam on top the latex would also contribute significantly to the feel and performance of this layering and even the layers below this would add their own effect as well.
If the density and type of memory foam and the ILD of the latex layering is chosen to match your body weight, sleeping positions, and preferences it could certainly be suitable IMO yes … but the devil is often in the details not just the type of materials themselves. Because of the resiliency and supportive qualities of of the latex, it would be less “risky” in terms of alignment than 4" of memory foam alone. I would choose a slightly firmer version of latex than would be typical if you were sleeping directly on it.
The difference in feel between different types of memory foam has little to do with its density and more to do with the specific “recipe” of chemicals that is used to make it. There is more information about this in post #9 here. Tempurpedic does have its own “feel” just like other types of memory foam but they are particularly poor value and if it was me I would look for memory foam that was in a similar density but had a firmer or denser “feel” than the Sensus. You are probably using “denser feel” as an indicator of how quickly the memory foam responds and you would probably be looking for memory foam with a slower response (and many of the newer memroy foams have a faster response because most people seem to prefer this). Of course if nothing else will do … then a Tempurpedic 2" layer may be worth the significantly higher cost for you even though the quality (density) would be no better.
The new Tempurpedic Weightless collection uses a similar type of layering with a relatively thinner layer of memory foam over a more resilient layer below it.
Some of the better online sources for toppers I’m aware of are listed in post #4 here and it may be well worth talking to some of them to see which memory foam they carry they believe would most closely match the Tempurpedic (although this would also depend on the thickness of the layers you are comparing and the other layers above and below it in the mix).
Overall I personally like the type of layering you are considering and if the surface of the Dux you are using it on is even and firm it could make a great choice.
Phoenix