Mattress Forum

While I agree that the top 2 layers create most of the effect ... I couldn't disagree with him more about the bottom layer having little effect. The laws of physics and "order of compression" completely contradict this as well as your own testing with 6" on the floor. The reason 2 sided mattresses like this work (including my own) is because it uses the laws of physics to advantage rather than disadvantage. A thin soft layer will rapidly compress and only allow a little "sinking down" (because it is softer and thinner) before the thicker middle layer of a 2 sided mattress "takes over". I don't like to disagree with anyone so strongly but in this case ... and with your one sided construction ... I'm sorry to say I have to.

So it sounds like you disagree with putting the firm talalay on top of the medium dunlop.

Since I've "black and white" disagreed enough for one day ... I'll just say I don't believe it's optimal.

On the other hand it sort of sounds like you like the idea of the medium dunlop on top of the firm talalay? Or are you saying just get the firm dunlop? (And I assume layer soft over med-dunlop over firm-dunlop?)

My preference would be the firm Dunlop if it was on the bottom. For the first 25% they would be the same firmness but after than the Dunlop (if it had the same 25% ILD) would be firmer and since firmness is what you need on the bottom ... why use Talalay when it would have no advantage? The only advantage of the Talalay would be if the bottom layer compressed less than 25% which is the only "level of compression" where it may be firmer than the Dunlop (it starts off firmer and ends up softer ... in other words the response curves "cross" as compression gets deeper). The firmer it is the more it will "encourage" the upper 2 layers to "interact" to your advantage.

As I said I just tested the "dunlop" vs "talalay" and think I prefer the feel of talalay. I've tried soft over medium over firm all dunlop and that didn't work. I'm sort of curious to try soft over med over firm all talalay (which I could do if I get the firm talalay layer). And I could always swap a medium dunlop back in if its not firm enough...

"Feel" is a very different thing and can mean many things. Some of the "feel" comes from what is on top and some of it comes from what is underneath. For example how an innerspring reacts can create a different feel even it it's ability to provide comfort and support is the same as a different material. If the feel you mean would really come from the lowest layer of talalay and if it was important enough to you ...  then yes it would make sense to use Talalay over Dunlop even at a "tradeoff" of pressure relief and/or support. I guess what I am trying to get to is whether the "feel" you mean is coming from the upper 3" (in which case using Dunlop in the lower layers would make no difference since the top is already Talalay) or if the "feel" you are meaning is coming from the deeper layers (in which case you would be trading the "feel" for something else).

The risk in using a middle medium Talalay over a medium Dunlop is that you would sink in further than a Dunlop of the same ILD. If you went firmer with the middle talalay layer to compensate for this then it wouldn't work as well as a comfort layer.

If you know what you are "trading" (feel/comfort/support) ... then it's easier to "visualize" what each layer change can lead to.

Phoenix.

PS: I believe it is in the "misunderstanding" of the differences between Dunlop and Talalay that many of the "battles" about which is "better" come from. They are different and these differences can be used either to advantage or disadvantage. Those who by "accident or design" get to the best pressure relief and support with one easily come to believe that it is better. Those who do the same with the other believe the opposite. Both can lead to a "perfect design" in terms of pressure relief and comfort with unlimited choices in layer thickness and ILD so the only "built in" advantage of one or the other is in how it feels (the "intangibles) and this is a matter of preference not "better or worse". There is not even as much difference between the two as there are differences between latex in general and other constructions ... although the difference in "feel" is certainly noticeable. I also prefer the "feel" of Talalay however I would not trade this feel for pressure relief or support.

"Feel" is a very different thing and can mean many things. Some of the "feel" comes from what is on top and some of it comes from what is underneath.... I guess what I am trying to get to is whether the "feel" you mean is coming from the upper 3" (in which case using Dunlop in the lower layers would make no difference since the top is already Talalay) or if the "feel" you are meaning is coming from the deeper layers (in which case you would be trading the "feel" for something else).

Well I liked the feel of soft talalay over 2 medium talalays better than I liked soft talalay over 2 medium dunlops. So I would say the difference is coming from the dunlop "pushing back" more from the bottom 2 layers. 

The risk in using a middle medium Talalay over a medium Dunlop is that you would sink in further than a Dunlop of the same ILD. If you went firmer with the middle talalay layer to compensate for this then it wouldn't work as well as a comfort layer.

I don't think I ever suggested this. The question is do I get a firm dunlop or talalay. In either case I would probably try soft over med over firm. If it didn't feel firm enough I think I would also try soft over firm over medium. I can also try swapping the medium between dunlop and talalay to see if that makes a difference. 

I'm really just trying to be specific about what you think would work best, and what the backup plan would be if it doesn't work. Sounds like buy the firm dunlop (from now on I'm just gonna type d for dunlop and t for talalay) and layer soft-t over med-d over firm-d. And if thats not firm enough try soft-t over firm-d over med-d. If its too firm try the med-t in the middle over firm-d. Correct?

I don't think I ever suggested this. (referring to using medium talalay)

When you said "I'm sort of curious to try soft over med over firm all talalay (which I could do if I get the firm talalay layer)" in the previous post I took it to mean that if you went in the direction of a firm Talalay on the bottom that you could "try" an all Talalay construction and that this possibility was attractive (which I certainly understand). This is why I commented on what the medium Talalay in the middle could lead to. I thought that the "temptation" of testing an all talalay construction may become a big part of a decision to buy firm Talalay instead of firm Dunlop so I thought I'd comment on what it could lead to so that you would know what you were trading.

Am I just misreading everyone today????

In any case, yes I do believe that firm Dunlop would be a better choice than firm Talalay (assuming they both had the same ILD). If the firmest Dunlop you could get was say 36 and the firmest Talalay was say 44, then Talalay would be the better choice IMO.

The first choice as you mentioned would be Firm Dunlop under medium Dunlop under soft Talalay.

The backup plan would be exactly as you suggested ...exchanging the two bottom layers and then possibly adding a thin layer of talalay to the mix (softer over or firmer under the 3" talalay) to "deepen" your cradle as I think that this configuration may need a "little more" comfort since the firm Dunlop in the middle wouldn't give you as much "soft thickness" as the medium.

The only reason I would change this is if I could buy firm enough Talalay that it would give the same benefits as the firmest Dunlop I could find ... or that the "lessening" of benefits would be worth "trading" for the ability to try all Talalay because of it's preferred "feel".

Phoenix

No, I just reread what you wrote and got it, so that ones on me lol. 

So OK  I will order the firm dunlop. But since the soft-t over med-d over med-d wasn't "soft enough" (in terms of comfort layer) than I also know that changing the bottom piece to firm won't help the top feel softer. So I really feel like I should also order another layer of thin talalay, or a good wool topper (although I see from other posts that you don't feel that wool really softens things). So I guess just a 1" or maybe 1.5" layer of soft (22ILD) talalay might work? Does it make sense to order that from Sleepez at the same time? And do you think 1" is enough?

Actually it would make a difference because of "order of compression". In medium d over medium d ... the lower layer is doing half the compressing when what you want is the middle layer to compress as much as possible before the lower layer "kicks in". It's the initial compression of the middle layer that will help form a cradle and become part of your comfort layer and if the bottom is too soft it won't do this. This is one of those situations that seems "counterintuitive" until an "aha" happens.

So I really feel like I should also order another layer of thin talalay, or a good wool topper (although I see from other posts that you don't feel that wool really softens things). So I guess just a 1" or maybe 1.5" layer of soft (22ILD) talalay might work? Does it make sense to order that from Sleepez at the same time? And do you think 1" is enough?

You may need a thin layer of soft talalay to add to this but with this layering (the top part of the middle dunlop is "acting soft") you may not need it. It may also be helpful to wait until this is tested so that it's easier to tell what is needed in the "final adjustments" so that they too can be more accurate. If you do need this then the odds are overwhelming that 1" would be enough but what remains to be seen is if it should be slightly firmer (in between the soft talalay and medium Dunlop) and go under the soft Talalay or if it should be softer than the upper talalay and go over it. How the initial setup feels with a wool mattress pad on top may affect this choice as well (a wool pad in general is not as "point elastic" as the underlying talalay and lessens how far you can sink in to a soft layer ... moreso as it compresses). Some pads do this less (like the thin Dormier) because  they are thinner and have a more elastic backing. Some thicker pads with a less elastic backing would do this more ... even though they may initially "feel" softer.

So ... for the sake of better choices in the last inch if it is needed ... I would wait till after you received this one.

Phoenix

All right, I am ordering the firm dunlop right after this. I will wait until I get it to see if I need more latex.

For the record, I do have a wool pad, but its thin wool with a stiff, rough backing, and I think it firms the bed quite a bit. So I dont use it.

Thanks again. You've been amazingly patient and nice about all this. If you are ever back in the Seattle / Redmond / Bellevue area you should let me buy you dinner as a thank you!

Steve

With pleasure . I have every intention of being there as much as I can since that is where my "heart" and other half (known in another thread as "Latex" lol) lives and it drives me nuts that a "border" can keep us apart as much as it does.

You've been just as patient.

Phoenix

Underneath the soft Talalay it may initially feel firmer (unmelted) but as heat reached it it could add to your cradle over time.

All of this would depend on how much it reacts to heat (visco) and how much it reacts to pressure (elastic).

Ice will melt with pressure for example not just heat ... and different memory foam formulations have different properties.

Phoenix

PS: there is an actual science behind all of this called Rheology and in the case of viscoelasticity it can get pretty complicated. With memory foam there is a property called creep which makes it especially difficult to predict in middle layers. This creep and it's low elasticity are what gives memory foam the small amount of "support" it does have and why you don't sink "all the way through it" as you would with honey. Enough to say that memory foam is "creepy" ... in more ways than one (laughing).

I just ordered the dunlop from Sleepez. Altho I keep thinking now how funny it is that this is essentially a progressive layering, when all along I think you were more favoring the differential layering for me. Thats why I thought I should buy 2 firm pieces, so I could do 4-4.5" soft over 6" firm (differential). So I sure hope this progressive scheme works! 

Steve