by For couples who want independent head and foot articulation on a split king, the Amerisleep AS3 paired with the Amerisleep Adjustable Bed is our top pick. Its Bio-Pur foam compresses cleanly for articulation with no buckling, the medium 5/10 feel suits a wide range of sleepers, and buying the mattress and base together keeps the bundle under one 100-night trial and one 20-year warranty. If one partner needs a significantly firmer surface, a split king allows pairing an AS3 on one side with an AS2 on the other, which no single-sided king mattress lets you do.
Amerisleep AS3
9.3/10
- Bio-Pur open-cell foam flexes cleanly with head and foot articulation, no buckling at the bend zones
- HIVE 5-zone layer firms under the lumbar and softens at the shoulders, so zero-gravity positioning still keeps the spine supported
- Split king format means each partner has a fully independent surface, zero motion transfer, each side articulates on its own
- CertiPUR-US certified, made in the USA, free shipping
- All-foam means slightly less bounce than a hybrid for active couples
- Sleepers over 230 lb may prefer the firmer AS2 or the AS5 Hybrid for their side of the split king
The AS3 is built to flex. Its plant-based Bio-Pur foam moves cleanly through every angle the Amerisleep Adjustable Bed throws at it, and the HIVE zoning keeps the lumbar supported whether you are sleeping flat or sitting up in zero gravity. For couples, a split king gives each person a fully independent mattress and base, which is the cleanest solution to different position and firmness preferences.
Why a split king adjustable base changes how couples sleep
A standard king mattress, even a good one, forces two sleepers to compromise. One person wants zero-gravity elevation for back decompression; the other wants to sleep flat. One partner snores and needs head elevation; the other is a side sleeper who does not want any incline. A split king adjustable base system solves this at the hardware level: each side of the bed operates completely independently, so both sleepers get exactly the position they need without disturbing the other side.
The variable most buyers underestimate is the mattress itself. Not all foam mattresses articulate well. A foam that is too dense or too thick at the transition zones will buckle or pull away from the base at the hinge points, reducing contact area and comfort. The Amerisleep AS3 uses a Bio-Pur open-cell foam that compresses cleanly through the full 60-degree head and 40-degree foot range of the Amerisleep Adjustable Bed without delaminating or buckling, which is why it is the mattress Amerisleep pairs with their base by default.
Amerisleep Adjustable Bed specs: what the standard base includes
| Feature | Amerisleep Adjustable Bed | Amerisleep Adjustable Bed+ |
|---|---|---|
| Head articulation | Up to 60 degrees | Up to 60 degrees |
| Foot articulation | Up to 40 degrees | Up to 35-40 degrees |
| Zero-gravity preset | Yes, one-touch | Yes, one-touch |
| Head-elevation preset (reduces snoring) | Yes | Yes |
| Massage | No | Yes |
| USB ports | No | Yes |
| Under-bed lighting | No | Yes |
| App + voice control | No | Yes (Alexa / Google) |
| Remote | Wireless backlit | Wireless + app |
| Weight capacity | ~700 lb (sleeper + mattress) | ~700 lb (sleeper + mattress) |
| Warranty | 10-year limited (tiered) | 10-year limited (tiered) |
| Split king availability | Yes | Yes |
| Approx. price (split king) | From ~$1,100 | From ~$1,800+ |
The standard Amerisleep Adjustable Bed covers the two positions that matter most for most couples: zero-gravity (both knees and head elevated to decompress the lumbar) and head-elevation-only (for snoring or acid reflux). Massage and USB ports are Bed+ features only. If you are buying specifically for positional flexibility and lumbar support, the standard base delivers the core use case at a lower price.
How split king independent articulation actually works
A split king is two twin XL mattresses placed side by side on two separate adjustable base units, sharing the visual footprint of a standard king. Each base unit has its own motor, its own remote preset memory, and its own power circuit. When Partner A moves their side to zero-gravity, Partner B is completely undisturbed because there is no shared mechanical linkage between the two halves.
In practice this means:
- One partner can elevate their head to 45 degrees to read or watch TV; the other sleeps flat with zero disturbance.
- One partner can activate the head-elevation preset for snoring while the other sleeps in zero-gravity with knees elevated.
- Both partners can use their own zero-gravity preset simultaneously, with foot elevation angles adjusted to their respective body proportions.
- Motion transfer is effectively zero: two separate mattresses on two separate bases means there is no material connecting the two sides that could transmit movement.
The only practical trade-off is a gap that can open between the two twin XL mattresses when both are articulated simultaneously. A split king connector strap keeps the mattresses flush when both sides are flat, but a small gap between the two foam slabs is normal when one or both sides are elevated.
Why the AS3 Bio-Pur foam works on an adjustable base
For a mattress to perform on an adjustable base, it needs to flex at the head and foot hinge points without damage or permanent deformation. The Amerisleep AS3 qualifies for three reasons:
All-foam construction: There are no coils, no rigid layers, and no hard boundary between comfort and support materials that would resist the bend. Bio-Pur and the HIVE layer are both foam, so they flex uniformly through the articulation range.
Open-cell foam structure: Bio-Pur is designed to be breathable, which requires an open-cell structure. Open-cell foam is inherently more flexible than closed-cell foam, and the AS3 does not have a high-density base layer so rigid it fights the motor.
Thickness in the compatible range: Very thick mattresses (14 inches or more) can stress at the hinge zone. The AS3 profile sits within the range Amerisleep rates compatible with their base, so the articulation geometry stays correct through the full motion range.
For more detail on what the base itself delivers day to day, see our full Amerisleep Adjustable Bed Base review, where we cover motor performance, remote control feel, and long-term durability in depth.
How to buy the AS3 plus adjustable base bundle
Amerisleep sells the mattress and base as a bundle through their website, which is typically the most cost-effective route for both pieces. For a split king, you configure two twin XL mattresses and two twin XL adjustable base units. The total split king bundle price varies depending on current promotions, but typically lands in the $3,000 to $4,000 range before discount codes, with Amerisleep running regular site-wide promos that can reduce the combined price by several hundred dollars.
A few things to confirm before checkout:
- Twin XL x 2, not king: A split king is two twin XL units. Make sure both the mattress and the base are configured as twin XL.
- 100-night trial covers both: Amerisleep's 100-night trial applies to both the mattress and the base when purchased together, so you are not stuck if the system does not suit your bedroom.
- 20-year mattress warranty, 10-year base warranty: The AS3 carries the full 20-year split warranty. The base warranty is 10 years (tiered: parts and labor year 1, mechanical and electrical year 2, prorated frame metal years 3-10).
- Free shipping: Both pieces ship free to the continental US.
- Financing available: Amerisleep offers Klarna 0% APR pay-in-4 and monthly payment options for larger amounts. A split king bundle typically qualifies for the longer-term monthly plans.
For couples with very different firmness preferences, remember that a split king lets you order different models on each side, for example AS3 on one side and AS2 (medium-firm) on the other, both on the same adjustable base system. This is a genuine advantage that a single-piece king mattress cannot offer.
Zero-gravity positioning and lumbar decompression
Zero-gravity elevates both the head (roughly 25 to 30 degrees) and the knees (roughly 15 to 20 degrees) simultaneously, placing the spine in a position where gravitational load on the lumbar discs is minimized. NASA originally identified this position as the one that reduced g-force stress on astronauts during launch, and it has since become the standard preset on quality adjustable bases for people who experience lower back pain in bed.
On a split king system, each partner can activate their own zero-gravity preset independently. For a couple where one person has chronic lower back pain and the other sleeps fine flat, this means the person who needs lumbar decompression gets it every night while their partner is not forced into a position that does not suit them.
The HIVE 5-zone layer in the AS3 is relevant here: even in zero-gravity, the zone 3 segment remains firmer under the lumbar than the shoulder or hip zones, so you do not lose lumbar support just because the head and foot are elevated. This is a meaningful advantage over a uniform-feel foam, which can allow the lumbar to sag when the position changes the load distribution.
The Amerisleep AS3 on a split king adjustable base is the most complete solution for couples with different sleep positions or back pain needs. Independent dual articulation, zero-gravity presets on each side, and the HIVE-zoned lumbar support in the AS3 all work together. Buy the bundle on amerisleep.com on a 100-night trial.
Frequently asked questions
Does the Amerisleep AS3 work with an adjustable base?
Yes. The AS3 is fully compatible with adjustable bases. Amerisleep sells it bundled with their own adjustable bed base and rates it compatible with the full head-elevation and foot-elevation range of the base. The all-foam Bio-Pur construction flexes cleanly without buckling or delaminating at the hinge zones.
What is the difference between the Amerisleep Adjustable Bed and the Adjustable Bed+?
The standard Adjustable Bed includes wireless remote, zero-gravity preset, and head-elevation preset. The Bed+ adds massage, USB ports, under-bed lighting, and app and voice control (Alexa and Google). If you are buying for positional flexibility and back pain support, the standard base covers the core use case at a lower price. Massage and USB ports are Bed+ exclusive and are not available on the standard model.
Can each side of a split king adjustable base move independently?
Yes. A split king is two twin XL mattresses on two independent base units with separate motors and remotes. Each side operates completely independently, so one partner can be in zero-gravity while the other sleeps flat, with no mechanical connection between the two sides to transmit motion.
Can I put two different Amerisleep mattress models on a split king base?
Yes, and this is one of the main advantages of the format. You can pair an AS3 on one side (medium) with an AS2 (medium-firm) on the other for a couple with different firmness preferences. Each mattress and base unit is purchased as twin XL, so the model selection is fully independent on each side.
What is the warranty on the Amerisleep Adjustable Bed?
The Amerisleep Adjustable Bed carries a 10-year limited warranty with tiered coverage: year 1 covers parts and labor, year 2 covers mechanical and electrical components, and years 3 through 10 cover the metal frame on a prorated basis. The AS3 mattress itself carries a separate 20-year warranty covering manufacturing defects and sagging over 1.5 inches.