Motion isolation is a measure of how well a mattress absorbs vibrations and prevents them from transferring across the surface of the bed. The better motion isolation a mattress has, the less movement you’ll feel when your partner gets in and out of bed or changes sleep positions during the night.
The Sleep Number Classic Series minimizes motion transfer. The airbed design of the c2 and c4 gives these beds a slight bounce, but the polyfoam comfort layers limit the spread of vibrations. However, an airbed model with a thicker comfort system may perform better in this category.
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Sleep Number Classic Series Mattress Review – Test Lab Ratings
Senior Product Editor
Methodology
Up-to-Date
Overall Rating
7.5
$999 from Sleep Number (queen)
Price Range: $699 – $3,898
Mattress Type: Airbed
Firmness Options: Adjustable – Soft (3) to Firm (8)
At a Glance
An airbed that allows the user to adjust the firmness of each side from soft to very firm. This is a great option for couples with different firmness preferences, and is relatively cheap for an airbed.
Ratings Summary
Motion Isolation
6/10
Edge Support
6/10
Temperature Control
6/10
Ease of Movement
6/10
Off Gassing
7.5/10
Pressure Relief
6/10
Pros
-
Adjustable firmness
-
Each side can be adjusted seperately—great for couples
-
Relatively affordable for an airbed
Cons
-
Delivery costs extra
-
While more affordable than many airbeds, models in the Sleep Number Classic Series are still more expensive than most more traditional alternatives
Table of Contents
Sleep Number, a well-known maker of airbeds, gets its name from the 1 to 100 scale it uses to represent firmness levels. Its mattresses are adjustable and allow users to fine-tune the firmness and comfort of their sleep surfaces.
The company produces high-quality, versatile models in a wide range of price-points. The Sleep Number Classic Series consists of two airbed mattress models, the c2 and the c4. Both use the company’s air chamber design that can be adjusted from a soft firmness level up to firm.
The c2 is more budget-friendly and features a 2-inch polyfoam comfort layer to add cushioning. The more c4 has a thicker, 3-inch comfort layer for extra plushness and pressure relief. We’ll break down what you need to know about both the Sleep Number c2 and the c4, covering everything from their construction and performance to Sleep Number’s customer service policies.
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Sleeping Style and Body Weight
Sleep Number c2 (Classic Series)
Sleeper Type
Side Sleepers
Back Sleepers
Stomach Sleepers
Side Sleepers
Its adjustable air chamber support core makes the c2 comfortable for many side sleepers.
Sleeping on your side concentrates your body weight along that side, placing a great deal of pressure on your shoulders and hips. A mattress that’s too soft can cause your shoulders and hips to sag into the bed’s surface, forcing the spine out of alignment. However, a mattress that’s too firm does not offer enough cushioning and can create painful pressure points. Most side sleepers do well with a mattress that’s medium to medium firm.
The adjustable design of the c2 allows side sleepers to determine the right level of support for them, while the 2-inch polyfoam comfort layer cushions their hips and shoulders. Most side sleepers under 230 pounds should be able to find an exceptionally comfortable setting. However, those who weigh over 230 pounds could sink through the comfort layer and press against the air chamber core, reducing the cushioning effect.
Back Sleepers
Sleeping on your back creates pressure in the lumbar area. A mattress that’s too soft allows the hips to sink into the mattress excessively, disrupting spinal alignment and potentially causing back pain. However, a mattress that’s too firm causes the hips to sit on top of the bed, creating a gap between the lower spine and mattress surface.
The Sleep Number c2 contains an air chamber support core that’s highly adjustable. With the ability to switch between soft, firm, and anywhere in between, the c2 provides a comfortable sleep surface for most back sleepers. The 2-inch polyfoam comfort layer provides exceptional pressure relief for back sleepers who weigh less than 130 pounds, but sleepers who weigh over 230 pounds may need a thicker comfort system for optimal cushioning.
Stomach Sleepers
Stomach sleepers are at a greater risk of back pain. Without enough support, your midsection can sink into your mattress, creating an unnatural U shape in the spine. Although stomach sleepers require a firmer sleep surface to maintain a good posture, most also prefer some cushioning.
The Sleep Number c2 offers the right amount of support and cushioning for many stomach sleepers. Since it is adjustable, stomach sleepers can fine-tune the firmness of the sleep surface to support their midsections and prevent back pain. With a 2-inch polyfoam comfort layer, the c2 also provides a moderate amount of cushioning for sleepers who weigh up to 230 pounds. Those who weigh over 230 pounds could sink in against the core, so they may prefer a bed with a thicker comfort layer.
Sleep Number c4 (Classic Series)
Sleeper Type
Side Sleepers
Back Sleepers
Stomach Sleepers
Side Sleepers
Like the c2, the c4 provides exceptional comfort for most side sleepers. Side sleepers tend to place a high amount of pressure on their hips and shoulders, requiring a balance between support and pressure relief to maintain spinal alignment and comfort throughout the night.
The c4 allows side sleepers to adjust their bed’s firmness from soft to firm to find the comfort level that suits their sleep style, comfort preferences, and body weight. A 3-inch polyfoam comfort layer adds extra cushioning compared to the c2. This additional inch of polyfoam enhances the pressure relief and helps prevent sleepers who weigh over 230 pounds from pressing against the support core.
Back Sleepers
Sleeping on your back puts pressure on your lower spine. The right balance of support and contouring can minimize discomfort by promoting good alignment.
The Sleep Number c4 is a strong option for back sleepers. The bed’s adjustable support core allows back sleepers to choose the best firmness level to support their back and suit their comfort preferences. Additionally, the thicker comfort layer of the c4 can provide extra cushioning for back sleepers who weigh more than 230 pounds, reducing the likelihood that they’ll press directly against the air chamber system.
Stomach Sleepers
Sleeping on your stomach concentrates much of your body weight onto your midsection and puts you at greater risk for back pain. A firmer mattress helps support the stomach and keep the spine aligned, while a moderate amount of cushioning may enhance the perceived comfort.
The c4 has a good balance of features to meet the unique needs of stomach sleepers. You can adjust the bed’s support core up to a firm setting to limit midsection sinkage. Additionally, the bed’s 3-inch polyfoam comfort layer gently cushions the body. While both the c2 and c4 can provide the support stomach sleepers need, those who weigh over 230 pounds may find the c4 more comfortable since its thicker comfort layer should reduce the sensation of pressing against the core.
Mattress Performance
In addition to the hands-on feedback from our team, we conduct a number of quantitative tests in our Test Lab. The below ratings are based on the experience of our testers.
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Sleep Number Classic Series Mattress Review Breakdown
The Sleep Number Classic Series is a line of airbeds consisting of the Sleep Number c2 and the Sleep Number c4. Not to be confused with temporary inflatable air mattresses, airbeds like the c2 and the c4 feature support cores that contain air-filled chambers. By adding or removing air from these chambers, you can fine-tune the bed’s firmness. With the ability to adjust anywhere between a soft (3) and firm (8), the c2 and the c4 are highly versatile.
Both models have separate air chambers on each side of the bed so that partners can select their own firmness preferences. You can adjust your Sleep Number Classic Series comfort settings via Sleep Number’s SleepIQ app or with a Sleep Number remote that is sold separately. In addition to their air chamber support cores, the c2 and the c4 both contain a soft outer cover and a gel-infused polyfoam comfort layer to enhance pressure relief.
The Sleep Number c2 and c4 can both be used with a Sleep Number FlexFit Adjustable Base. The adjustable base allows you to make additional changes to your sleep surface, all controlled by the SleepIQ app or Sleep Number remote. Different FlexFit models offer varying features, including raising or lowering the head and foot of your bed, underbed lighting, and foot warming.
Sleep Number also offers split king, FlexTop king, and FlexTop California king mattress sizes so that each sleeper can adjust their position settings independently. These specialty sizes must be purchased with a Sleep Number adjustable base.
The c2 and the c4 are similar in terms of their general designs and support cores. However, the beds have some important differences. The c4 is the more expensive of the two models with a thicker comfort system for extra cushioning and contouring.
Sleep Number c2 Mattress
|
Firmness |
Adjustable – Soft (3) to Firm (8) |
|---|---|
|
Mattress Type |
Airbed |
|
Construction |
The c2 features a polyfoam comfort layer atop an adjustable support core of dual air chambers. Cover Material:Poly Blend Comfort Layer:2″ Gel-Infused Polyfoam Support Core:Air Chambers |
Sleep Number c4 Mattress
|
Firmness |
Adjustable – Soft (3) to Firm (8) |
|---|---|
|
Mattress Type |
Airbed |
|
Construction |
The c4 is an adjustable mattress with a thick polyfoam comfort layer and a support core composed of dual air chambers. Cover Material:Poly Blend Comfort Layer:3″ Gel-Infused Polyfoam Support Core:Air Chambers |
Sleep Number Classic Series Mattress Sizing
The Sleep Number Classic Series includes two models, the c2 and the c4. When compared to other airbeds available on the market, the Sleep Number Classic Series is relatively affordable. Although the c2 and c4 do not qualify as budget models, their prices are more in line with high-quality hybrid or memory foam mattresses. The c2 has a lower price-point than the c4. This is due primarily to the c4’s thicker comfort layer and additional inch of height.
Each Sleep Number Classic Series model comes in several size options outside of the standard twin through California king to better combine with an adjustable base. This includes the FlexTop king and FlexTop California king, which allow you and your sleep partner to raise or lower the head on each side of the mattress. Similarly, the split king option enables you to independently adjust both the head and the foot of each side of your bed.
Sleep Number has several adjustable base models that you can control with the SleepIQ app. All options come with underbed lighting and some level of adjustability, while more advanced models include a wider range of adjustable positions. The most expensive adjustable base by the company also includes a foot-warming feature.
Sleep Number c2 Mattress
| Sizes | Dimensions | Height | Weight | Price |
|---|---|---|---|---|
| Twin | 38″ x 75″ | 8″ | N/A | $699 |
| Twin XL | 38″ x 80″ | 8″ | N/A | $799 |
| Full | 54″ x 75″ | 8″ | N/A | $899 |
| Queen | 60″ x 80″ | 8″ | 52 lbs. | $1,099 |
| King | 76″ x 80″ | 8″ | N/A | $1,599 |
| California King | 72″ x 84″ | 8″ | N/A | $1,599 |
| Split King | 38″ x 80″ (2 pcs.) | 8″ | N/A | $3,898 |
| FlexTop King | 76″ x 80″ | 8″ | N/A | $3,898 |
| FlexTop California King | 72″ x 84″ | 8″ | N/A | $3,898 |
Sleep Number c4 Mattress
| Sizes | Dimensions | Height | Weight | Price |
|---|---|---|---|---|
| Twin | 38” x 75” | 9” | N/A | $1,399 |
| Twin XL | 38” x 80” | 9” | N/A | $1,499 |
| Full | 54” x 75” | 9” | N/A | $1,549 |
| Queen | 60” x 80” | 9” | 61 lbs. | $1,699 |
| King | 76” x 80” | 9” | N/A | $2,199 |
| California King | 72” x 84” | 9” | N/A | $2,199 |
| Split King | 38” x 80” (2 pcs.) | 9” | N/A | $4,498 |
| FlexTop King | 76” x 80” | 9” | N/A | $4,498 |
| FlexTop California King | 72” x 84” | 9” | N/A | $4,498 |
Trial, Warranty, and Shipping Policies
Availability
The Sleep Number Classic Series is available both in stores and online. For sleepers who prefer the in-person shopping experience, Sleep Number operates a large network of over 600 locations across the United States. You can check the company’s website to find a Sleep Number store near you.
If you’re looking to buy online, you can purchase the Sleep Number Classic Series directly through the company’s website.
Shipping
Sleep Number ships to all 50 states. The company doesn’t currently offer international shipping for mattresses.
Although some products on the Sleep Number website qualify for UPS shipping, Sleep Number ships its mattresses using a premium delivery service in select areas. The company charges a flat fee of $199 for premium shipping and delivery. Additional charges may apply for orders outside the main service area.
On delivery day, a Sleep Number technician will bring your mattress, set it up in your room of choice, and remove your old mattress and any packaging materials. An adult must be present for delivery.
Additional Services
Sleep Number mattresses include in-home delivery, assembly, and old mattress removal for a flat fee of $199. Additional charges may apply for addresses outside of the company's main service areas.
Sleep Trial
Sleep Number mattresses come with a 100-night sleep trial, which begins the day your new mattress arrives. Sleep Number requires a 30-day break-in period for you to adjust to your new mattress. If you're not satisfied after 30 days, you can exchange it for another model or return it for a refund of the purchase price. Return shipping fees apply.
Warranty
The models in the Sleep Number Classic Series are protected by the company’s 15-year limited warranty. The warranty begins on the date of purchase and protects your mattress against defects in materials or workmanship under conditions of normal use.
For the first year, the mattress is protected by a full warranty. Sleep Number will repair, replace, or refund your mattress or its components if it confirms a qualifying defect.
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Lauren is a Certified Sleep Science Coach with extensive experience researching and testing a wide variety of sleep products.