Looking for opinions on coil firmnesses. Ive noticed brands like aireloom, or other luxury brands use very firm coils, while having a significant amounf of materials on top.
I do not understand how the assembly works together in this way. It seems like all of the layers do the work because they’re pressed up against a very firm spring base that does not compress at all.
Is it generally better to maximize the function of a mattress by constructing it with slightly flexible coils, and using a moderate amount of comfort material, leaving the total height at around 12"? Or to use firm coils, thus having to increase the amount of comfort layers and having a taller total height?
You hit on a fundamental structural debate in mattress design, and your observation is correct.
When brands like Aireloom use a rigid coil base, the upper comfort layers do the work for pressure relief. The firm spring base underneath acts as an unyielding floor. Manufacturers build them this way to provide progressive resistance for spinal alignment, to support the weight of heavy materials like wool or latex, and to create a cradled sensation. The tradeoff is that a thick 14-inch profile requires a lot of materials that can trap heat or pack down over time if they are not top-tier quality. Most people don’t need a 14"+ mattress.
Conversely, using a responsive, flexible coil system with a moderate comfort layer while keeping the bed around 12 inches more efficiently maximizes mattress mechanics. In this setup, the steel springs and the comfort layers work together. The pocketed coils compress to cushion your shoulders and hips, so you do not need six inches of padding on top to achieve comfort. This design improves breathability and reduces the risk of body impressions over time.
Neither philosophy is universally superior, but they suit different sleepers. The firm coil with deep comfort layers works well if you prefer a traditional, deep-quilted luxury feel. The flexible coil with a moderate top layer is effective if you want active, responsive contouring and a cooler, resilient bed.
Great observation, and @NikkiTMU covered it with great info.
I’m a believer that the base layer is the heart of the build, and everything above it should complement it. Personally, I don’t see much benefit in using a premium pocket spring unit if you’re going to bury it under an excessive amount of comfort material, other than making the mattress compressible so it can be roll-packed and shipped in a box, something theopen coils can’t do.
As the comfort layers get thicker, they begin to mask many of the characteristics that make pocket springs desirable, such as their contouring and independent response. The springs are still providing support, but their spring isolation is much less noticeable. In my view, a well balanced design lets the comfort layers relieve pressure while still allowing the pocket springs to do what they were designed to do.
I’ve always looked at mattress construction the same way you’d approach building a house or structure. The foundation determines how well everything above it performs. A strong, well-engineered support core gives the comfort layers a stable platform to do their job consistently, regardless of whether the sleeper is lighter, heavier, or somewhere in between. Likewise, the same goes for the comfort layers above the supporting spring support, whether soft, med, firm, plush or hard.
That said, the foundation shouldn’t be mistaken for the entire comfort system. The more logical and thoughtful designs create synergy between the support core and the comfort materials rather than asking one component to do all the work. If the coil unit is overly rigid, the comfort layers have to carry almost the entire burden of pressure relief. If the comfort package is excessively thick, it can mask many of the benefits of a premium pocketed coil, such as contouring, responsiveness, and independent movement. Regardless, the support layer is where it all begins and sets the tone for the rest of the build and what it can handle.
For me, I like to go with a balanced sweet spot. I want a robust support system that can maintain alignment over the long term, paired with just enough quality comfort material to provide pressure relief while still allowing the support core to contribute to the overall feel. When each layer is allowed to do what it was designed to do, the result is a mattress that’s more efficient, more durable, and often more comfortable than one that relies heavily on any single component.
Just my take on it, although we are all basically saying the same thing.