Hi Glenn,
This is some good feedback and is really helpful. It also “points” in the same direction as your previous testing.
This was not so much a recommendation as it was a suggestion to try very soft latex so you could have a sense of how the softest latex felt in comparison to memory foam which is about the same ILD but feels very different. If both firmer latex and softer latex has roughly the same pressure relief and both feel good to you … I would always choose the firmer. softer is only necessary if you need or prefer a deeper cradle (more sinking in). For most people … 19 ILD or even latex up to 24 ILD is good.
One of the difficulties with Dunlop is that it’s hard to know exactly what firmness you have. The range of 22-30 is all the way from soft to medium in Talalay and if you have a 22 ILD in one version and a 30 in another they will feel and perform very different. This kind of variability is part of the Dunlop process while Talalay has a more consistent ILD across the surface. This is also why actual testing is more accurate … especially with Dunlop … because the mattress you are testing may use firmer or softer Dunlop even if it is rated the same. Which part of the core a 3" layer was cut from (top or bottom) will also make a difference in the softness of a 3" Dunlop layer because the bottom 3" of a 6" core is firmer than the top even though their rating would be from the rating of the 6" core. What happens is that the full core is rated and then every thinner layer that is cut from it is rated as a thinner piece of the same ILD. Most people will notice an ILD difference of about 4 or so but some are more sensitive and the difference can also be more apparent over the course of a night.
My thoughts are also that only the heaviest people need more than 9" of latex unless there is a specific reason for it (such as some forms of zoning or progression). In this case … I don’t think there would be any real benefit even though they will feel a little different.
I will make a few assumptions about the Savvy Rest layers for ease of description and for the sake of comparisons even though they are “best guesses” and not necessarily accurate (for the reasons I just mentioned). These assumptions are that the “soft” Talalay they offer is N2 natural talalay which according to the Latex international website is 22 ILD on average. We’ll assume that the soft Dunlop is about 26 ILD on average, that the medium is about 35 on average, and that the firm is about 44.
So using the 3 layer Savvy Rest mattress with 3" of soft talalay over 3" of medium Dunlop over 3" of firm Dunlop as a reference …
This would be the rough equivalent of 2" of soft Talalay over a medium (28 ILD is usually called medium) 6" layer of Talalay in terms of both pressure relief and support (this is your wife’s side). This would be about as close as you could get to the Savvy Rest in terms of pressure relief with a mattress with a 6" + 2" construction in Talalay using the available materials. This is because the top inch or so of the 28 ILD (28 ILD means it takes 28 lbs to compress a 6" layer by 1.5") Talalay support core would be the equivalent of about 22 ILD in the first inch of compression (less weeight compresses it less) and would act as part of your comfort layer on top. When you compressed it further it would get firmer and act as part of the support system of your mattress. This is a progressive construction where the top part of the support layer acts as part of your comfort layer.
So what I would suggest (for you) is this …
Try sleeping on your wife’s side for a couple of nights (if you haven’t already) to see if the 2" of soft Talalay over the “soft” (actually medium 28 ILD) talalay support core is good for pressure relief and alignment. The type of feedback that would be valuable would be specific in terms of pressure relief and spinal alignment rather than more subjective feelings of soft or firm. This will tell us whether changing the support core on your side to 28 ILD talalay will solve the issue.
Your specific feedback on your wife’s side would help determine what may be next. I would think that you will not need more than 1" to 2" of soft Talalay on top of what you have if your wifes side isn’t suitable. 1" would give you 3" of soft latex similar to the Savvy Rest but there would also be a layer of ticking and quilting mixed in with this top 3" (in between the top 2" of your mattress and the 1" topper) which would firm it up a bit. This is why you may need 2" instead of the more “exact” duplication of the 3" Savvy Rest layer.
This may (or may not depending on your experience) need a firmer support layer underneath it for best alignment. I would think that this extra comfort layer may do best on the firmer latex on your side of the mattress (the comfort layer wouldn’t need any “help” any more) and you could even choose a firmer 6" layer underneath it if you needed even more support.
As far as possibilities for your wife … it would help to have her specific feedback (in terms of pressure relief and alignment) about your current mattress and the savvy rest. The medium Talalay over soft Dunlop over medium Dunlop would be the rough equivalent in talalay (using 3" layers) of soft over medium over firm. Because she is lighter … she may need an even softer topper in the range of 14 - 19 depending on what exactly she is experiencing on what you have and what you’ve tried.
So let me know the specifics of what happens when you sleep on your wife’s side for a couple of nights and also her specific feedback on the savvy rest and your current mattress in terms of pressure relief and alignment and then it will be much easier to decide what may be the best next step.
Phoenix