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Originally founded as Select Comfort in 1987, Sleep Number is one of the country’s leading providers of airbed mattresses. Today, the company has a major brick-and-mortar and online presence. Sleep Number currently offers a handful of airbed mattress models. In this review, we’ll look at the two models in the brand’s Classic Series collection.
The c2 is Sleep Number’s most affordable mattress, as well as one of the company’s most popular models. This airbed is constructed with a polyfoam comfort layer over a support core with two adjustable air chambers. Adding or releasing air from each chamber can adjust how soft or firm the mattress feels. The c2’s given firmness range is medium firm to firm, falling between a 6 and 8 on the 1-10 firmness scale.
The c4 is the more expensive model in the Classic Series. This airbed shares a similar design as the c2, but its polyfoam comfort layer is 1 inch thicker. This provides a wider firmness range for the c4, which offers a feel between medium (5) and firm (7-8) depending on how much air is in its support chambers.
Both the c2 and c4 are both equipped with sensors that track time asleep and awake, sleep position changes, and other nightly patterns. You can access personal sleep data using the proprietary SleepIQ app on your smartphone or tablet device, though you’ll need a Wi-Fi connection in your bedroom. All Sleep Number airbeds are compatible with the SleepIQ app. In addition to the c2 and c4, these models include three airbeds in the Performance Series; three airbeds in the Innovation Series; and the m7 mattress in the Cooling Memory Foam Series. Each Sleep Number airbed offers a different firmness range.
If you’re interested in the c2 or c4, keep reading our Sleep Number Classic Series review to learn more about these models. Below, you’ll find current prices, construction details, performance ratings for both beds, and an overview of Sleep Number’s delivery, return, and warranty policies.
Choose the c2 if…
Choose the c4 if…
The c2 airbed is constructed with a 2-inch layer of gel-infused polyfoam. This material is fairly adaptive and will conform to your body, but it also feels more responsive than memory foam and creates a light bounce on the surface. The bed’s support core consists of two adjustable air chambers, one on each side. The dual-chamber design allows you to adjust the feel of each side of the mattress, making the bed ideal for couples with differing preferences. The c2’s cover is made from a blend or rayon and polypropylene, giving the fabric a smooth and breathable feel. Altogether, this mattress measures 8 inches thick, making it a low-profile model.
The c4 features a 3-inch comfort layer of gel-infused memory foam. Added thickness to this layer creates a wider firmness range for the adjustable air chambers. While the c2 can be set for a feel between medium firm (6) and firm (7-8), the c4 provides a range of medium (5) to firm (7-8). As a result, people who weigh less than 130 pounds will probably feel a bit more comfortable on the c4. The c4’s cover is made from a blend of polyester and polypropylene, but it offers the same smooth and cooling feel as the c2’s cover. The c4 measures 9 inches thick, and is also considered a low-profile mattress.
Both beds can be adjusted using the remote-controlled Firmness Control System. This system corresponds to air hoses connected to each chamber. The remote is equipped with arrow buttons to make the bed feel softer or firmer.
The c2 and c4 also feature built-in sensors to track your sleep patterns using the SleepIQ app. Each morning, you’ll be able to check up-to-date data regarding your REM cycles, time asleep and awake, position changes, breathing patterns, and other personal metrics. The app assigns a numerical score based on how well (or poorly) you’ve slept.
Except for some slight comfort layer thickness and firmness range differences, the c2 and c4 are quite similar. A full breakdown of each bed is listed below.
Rayon and polypropylene blend
2″ gel-infused polyfoam
6″ adjustable air chambers (x2)
Polyester and polypropylene blend
3″ gel-infused polyfoam
6″ adjustable air chambers (x2)
Polyester and polypropylene blend
3″ gel-infused polyfoam
6″ adjustable air chambers (x2)
The c2 airbed is constructed with a 2-inch layer of gel-infused polyfoam. This material is fairly adaptive and will conform to your body, but it also feels more responsive than memory foam and creates a light bounce on the surface. The bed’s support core consists of two adjustable air chambers, one on each side. The dual-chamber design allows you to adjust the feel of each side of the mattress, making the bed ideal for couples with differing preferences. The c2’s cover is made from a blend or rayon and polypropylene, giving the fabric a smooth and breathable feel. Altogether, this mattress measures 8 inches thick, making it a low-profile model.
The c4 features a 3-inch comfort layer of gel-infused memory foam. Added thickness to this layer creates a wider firmness range for the adjustable air chambers. While the c2 can be set for a feel between medium firm (6) and firm (7-8), the c4 provides a range of medium (5) to firm (7-8). As a result, people who weigh less than 130 pounds will probably feel a bit more comfortable on the c4. The c4’s cover is made from a blend of polyester and polypropylene, but it offers the same smooth and cooling feel as the c2’s cover. The c4 measures 9 inches thick, and is also considered a low-profile mattress.
Both beds can be adjusted using the remote-controlled Firmness Control System. This system corresponds to air hoses connected to each chamber. The remote is equipped with arrow buttons to make the bed feel softer or firmer.
The c2 and c4 also feature built-in sensors to track your sleep patterns using the SleepIQ app. Each morning, you’ll be able to check up-to-date data regarding your REM cycles, time asleep and awake, position changes, breathing patterns, and other personal metrics. The app assigns a numerical score based on how well (or poorly) you’ve slept.
| Sizes | Dimensions | Height | Weight | Price |
|---|---|---|---|---|
| Twin | 38"x 75" | 8-9" | - | $599-1,199 |
| Twin XL | 38"x 80" | 8-9" | - | $699-1,299 |
| Full | 54" x 75" | 8-9" | - | $799-1,349 |
| Queen | 60" x 80" | 8-9" | - | $999-1,499 |
| King | 76" x 80" | 8-9" | - | $1,499-1,999 |
| California King | 72" x 84" | 8-9" | - | $1,499-1,999 |
c2: 2/5, c4: 3/5
The c2’s comfort layer is constructed with 2 inches of polyfoam. This material conforms a bit to your body but it feels fairly responsive, resulting in a light bounce on the surface. The material may absorb some movement from sleepers, but this mattress does not eliminate much transfer.
The c4 provides slightly better motion isolation due to its thicker comfort layer and softer feel, but this mattress will not eliminate much more transfer. Additionally, Sleep Number mattresses can be somewhat loud due to their electrical components. The noise potential and below-average motion isolation means you and your partner may experience some sleep disruptions on either mattress.
The polyfoam used in the c2’s and c4’s comfort layers has some adaptive qualities and conforms to a noticeable extent, but it does not offer the deep body contour of memory foam. This may result in less-than-adequate pressure relief for side sleepers, who often need deep cushioning for the shoulders and hips for even spinal alignment.
That said, the customizable feel of these airbeds can result in less pressure for some individuals. The softer firmness levels of these mattresses – the c4, in particular – will contour more closely, which may alleviate pressure points for people who weigh less than 130 pounds. Firmer feels could potentially mean better reinforcement and less sagging for people who weigh more than 230 pounds, but some people in these weight groups will find the beds too short and lacking in support.
The c2 offers good perimeter support. You’ll notice some sinkage when getting on and off the mattress, and you may not feel comfortable sleeping near the edges – especially if you weigh more than 230 pounds – but the bed’s firmer overall feel prevents excessive sagging. The air chamber support core offers a bit of reinforcement, but not as much as the coil systems or latex found in the base layers of other mattresses.
The c4 has a softer feel and a thicker comfort layer, so you should expect more sinkage when sitting or sleeping along the edges of the mattress. This issue may worsen over time as the foam begins to deteriorate. Due to the low profiles of the c2 and c4, people who weigh more than 230 pounds may not feel comfortable getting in and out of either mattress.
c2: 2/5, c4: 3/5
The c2 offers good perimeter support. You’ll notice some sinkage when getting on and off the mattress, and you may not feel comfortable sleeping near the edges – especially if you weigh more than 230 pounds – but the bed’s firmer overall feel prevents excessive sagging. The air chamber support core offers a bit of reinforcement, but not as much as the coil systems or latex found in the base layers of other mattresses.
The c4 has a softer feel and a thicker comfort layer, so you should expect more sinkage when sitting or sleeping along the edges of the mattress. This issue may worsen over time as the foam begins to deteriorate. Due to the low profiles of the c2 and c4, people who weigh more than 230 pounds may not feel comfortable getting in and out of either mattress.
“Ease of movement” refers to how deeply a mattress sinks when you travel across the surface. If the comfort layer sinks too much, you’ll probably have a harder time getting in and out of bed. Both the c2 and c4 feature polyfoam comfort layers that feel more responsive and bouncy than memory foam. You may notice some sinkage when moving on the surface, but not as much as you would on a bed with a memory foam comfort layer.
That said, ease of movement for either mattress depends on the selected firmness level. The c2 is easier to move across with a firm feel than a medium firm, since the latter will conform more closely and sink more. Overall, the c2 is easier to move across than the c4, which can be set to an even softer feel.
c2: 2/5, c4: 3/5
For most couples, the ideal mattress for sex will pro
vide an even balance of conforming and responsiveness. A closer contour ensures deeper traction, which helps you and your partner maintain a fixed position, while a bouncy surface allows you to move and change positions rather easily.
By these standards, the c2 is better for sex than the c4. The c2 conforms a bit for added traction but won’t sink too deeply, so you and your partner can move freely. This mattress also has stronger edge support, allowing you to use the entire surface of the mattress (though you may feel some instability along the perimeter).
The c4 may not be as suitable for sex. This is especially true for the bed’s medium feel, which sinks more and can restrict movement for you and your partner. Weaker edge support may also confine you to the middle of the mattress. With a medium firm or firm feel, the c4 performs slightly better.
Most mattresses emit some initial odor when new, but models with polyfoam and/or memory foam layers tend to produce the strongest and longest-lasting smells. The c2 and c4 have foam layers, but odor potential is fairly low for these airbeds. This can largely be attributed to their support cores, which generate enough airflow to clear out unwanted odors rather quickly.
Additionally, Sleep Number mattresses are delivered via White Glove couriers and are not compressed into a box. Mattresses that are compressed for shipping often release chemical smells when you unbox them. Since the c2 and c4 have more time to air out, they are less likely to emit strong odor when they arrive at your residence.
Highlights:
Side Sleepers:
Side sleepers generally prefer mattresses with softer feels. This ensures ample cushioning for their shoulders and hips without sagging too much, which promotes even spinal alignment and can reduce pressure throughout the body.
The c2 can be adjusted anywhere between medium firm (6) and firm (7-8). This range is a bit lower than the average airbed, and can be attributed to the c2’s relatively thin comfort layer. Side sleepers who weigh between 130 and 230 pounds are most likely to find the c2 comfortable. Those who weigh less than 130 pounds may find the mattress too firm, regardless of the chosen firmness level. For side sleepers who weigh more than 230 pounds, the firmness may be sufficient but these individuals are likely to find the mattress a bit too short.
The c4 offers a wider range of firmness levels, including a medium feel on its softest setting. This makes the mattress better suited to side sleepers who weigh less than 130 pounds, in addition to those who weigh between 130 and 230 pounds. Side sleepers weighing more than 230 pounds may still find the mattress a bit too short, but its firmer levels should be reasonably comfortable.
Back Sleepers:
Back sleepers tend to require a firmer mattress feel than side sleepers. Their spines align naturally, so most prefer a more balanced feel that conforms a bit while keeping their body on an even plane and not sagging beneath the torso, lower back, or hips.
The c2 should offer enough reinforcement for back sleepers who weigh up to 230 pounds. Its firmness range ensures they won’t sink too deeply, but the foam conforms closely enough to alleviate pressure in different areas of the body. Back sleepers who weigh more than 230 pounds are likelier to sink too much between their shoulders and hips. When the body is not on an even plane, the potential for added aches, pains, and pressure points is much higher.
The c4’s softer range will be ideal for many back sleepers who weigh less than 130 pounds. Their bodies shouldn’t sink too much (if at all), resulting in even support from head to toe. Those who weigh 130 pounds or more may experience more sinking if the mattress is set to a medium feel, but its medium firm and firm feels may be more suitable.
Stomach Sleepers:
For most stomach sleepers, the most comfortable mattress provides enhanced support for the midsection and hips. People tend to carry more weight in these areas than elsewhere in their body and sleeping face-down can cause their body to sink too much beneath the surface, leading to added neck, shoulder, and lower back pain.
Neither the c2 nor the c4 are particularly well equipped for stomach sleepers. Although both beds can be set to firmer settings, stomach sleepers will probably still sink a bit due to the adaptive polyfoam comfort layers. We recommend a medium firm or firm feel for stomach sleepers weighing 130 pounds or more. Those who weigh less than 130 pounds will probably prefer the medium feel of the c4.
However, stomach sleepers are more susceptible to aches and pains than those who use other sleep positions. For this reason, it’s possible that a stomach sleeper may experience discomfort on either mattress due to issues with their normal position, rather than the mattress itself.
| Under 130 lbs. | 130-230 lbs. | Above 230 lbs. | |
|---|---|---|---|
| Side Sleepers | Fair | Good | Good |
| Back Sleepers | Good | Very Good | Very Good |
| Stomach Sleepers | Good | Very Good | Good |
| Under 130 lbs. | 130-230 lbs. | Above 230 lbs. | |
|---|---|---|---|
| Side Sleepers | Excellent | Excellent | Fair |
| Back Sleepers | Good | Fair | Fair |
| Stomach Sleepers | Good | Fair | Poor |
The c2 and c4 mattresses are exclusively sold through Sleep Number. Previously, both were sold on Amazon.com, but both of their Amazon.com pages have been discontinued. You may purchase your mattress online using Sleep Number’s website, or at one of the company’s 611 brick-and-mortar locations across the U.S.
Sleep Number ships mattresses to all 50 states, Puerto Rico, and the U.S. Virgin Islands.
All mattresses are shipped via White Glove delivery. This service includes scheduled delivery date and time, in-home assembly, and old mattress removal upon request. Delivery costs $199 for all customers, but those outside the contiguous U.S. pay an additional $200 for the mattress itself. Sleep Number does not offer standard ground shipping.
Since White Glove couriers deliver the mattresses, they will not be compressed for shipping. Once the delivery personnel are finished assembling the mattress, you will be able to sleep on it. Delivery also includes a brief tutorial about changing the firmness and addressing potential maintenance issues.
Sleep Number offers a 90-night sleep trial for the c2 and c4. This trial includes a mandatory break-in period of 30 nights. You won’t be able to return the mattress for a refund or exchange it for another model until after testing it out for at least 30 nights.
Sleep Number provides a full product refund for all returns within 90 nights, but the shipping charges are non-refundable.
The c2 and c4 each come with a 25-year warranty. These warranties are partially prorated, and divided into the following schedule:
The SleepIQ sensors and Firmness Control System remote are each covered under a separate two-year warranty. If you believe your mattress, SleepIQ sensors, or remote control have a defect, contact Sleep Number to initiate a warranty claim.
