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Sleep Number Classic Series Mattress Review

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Written by

Lauren Fountain

author
sleep-number-c2-mattress-2

Ideal for:

  • Couples with different comfort preferences
  • Anyone searching for a highly adjustable bed
  • Side sleepers and those who weigh under 130 pounds

Considerations:

  • 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.
  • The dual-chamber design may create an uneven surface for sex.
Price Range:
$699 - $3,898
Mattress Type:
Airbed
Firmness:
Adjustable - Soft (3) to Firm (8)
Use this SleepFoundation.org link for the most current discount on Sleep Number mattresses

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.

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 Options

Mattress Type

Adjustable – Soft (3) to Firm (8)

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 Options

Mattress Type

Adjustable – Soft (3) to Firm (8)

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

Mattress Prices and 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
Scroll L - R for more details

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
Scroll L – R for more details

Discounts and Deals

Sleep Number

Use this SleepFoundation.org link for the most current discount on Sleep Number mattresses

Mattress Performance

Motion Isolation

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.

Pressure Relief

The airbeds in the Sleep Number Classic Series provide moderate pressure relief. This metric measures the degree to which a mattress contours to the shape of your body and redistributes its weight. Sleepers may have different pressure relief preferences depending on their body weight and sleep position.

Most of the pressure relief from the Classic Series models comes from their polyfoam comfort layers. The adjustable firmness also means that sleepers with different pressure relief needs can transform the surface as needed.

However, the Sleep Number Classic Series may not be ideal for sleepers who enjoy the deep contouring and additional pressure relief of a thicker comfort system.

Temperature Control

The Sleep Number Classic Series maintains a fairly neutral temperature during the night. The polyfoam comfort system is thick enough to provide moderate contouring without hugging so closely as to trap excessive heat. Additionally, a gel infusion in the polyfoam is designed to help the surface stay cooler by transferring heat away from the sleeper. This temperature control is on par with many airbeds and should satisfy most sleepers.

Edge Support

3/5 (c2)
2/5 (c4)

Edge support refers to how well the sides of a mattress support the weight of your body, which affects the amount of usable sleep space and the ease of getting into and out of bed.

The Sleep Number Classic Series models provide support along their perimeters. Hybrid and innerspring models frequently offer sturdier support, but the c2 and c4 have stronger edges than many all-foam and memory foam mattress models.

The c2 offers superior edge support to the c4 due to its slightly thinner polyfoam comfort system. Additionally, the firmer settings of the c2 and the c4 provide more support along the perimeter by limiting sinkage

Ease of Movement

Sleepers should find it fairly easy to move around on both the c2 and the c4, especially when using the firmer settings. Their polyfoam comfort layers relieve pressure and reduce motion transfer while responding quickly to changes in pressure so that sleepers are unlikely to feel trapped in the bed. This should make it easier to change positions as needed.

Sex

The dual-chamber design of the Sleep Number Classic series models is well-suited for customizing comfort for couples. However, this feature essentially splits the bed’s support core into two sections, creating a slight depression in the middle of the mattress that may not be ideal for sex. However, the firmer settings should allow couples to move on the bed relatively easily, which may facilitate amorous activity.

Off-Gassing

Off-gassing refers to the release of volatile organic compounds (VOCs) after unboxing your new mattress. VOCs are a byproduct of manufacturing. Although they aren’t generally considered harmful, they can give off a noticeable smell.

Synthetic materials, such as polyfoam and memory foam, tend to produce more odors than other mattress materials. Beds that have been compressed and boxed for shipping immediately after production are also more likely to emit an odor since they haven’t had time to air out.

Because of their air chamber cores, the models in the Sleep Number Classic Series are not prone to off-gassing.

That said, the c2 and the c4 contain polyfoam comfort layers, so you may notice a slight smell at first. However, any odor should be minor and short-lived, especially when compared to a foam-based mattress.

Sleeping Style and Body Weight

Sleep Number c2 Mattress

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.

Under 130 lbs. 130-230 lbs. Above 230 lbs.
Side Sleepers Excellent Excellent Fair
Back Sleepers Excellent Good Fair
Stomach Sleepers Excellent Good Fair
Scroll L - R for more details

Sleep Number c4 Hybrid Mattress

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.

Under 130 lbs. 130-230 lbs. Above 230 lbs.
Side Sleepers Excellent Excellent Good
Back Sleepers Excellent Good Good
Stomach Sleepers Excellent Good Good
Sleep Number

Use this SleepFoundation.org link for the most current discount on Sleep Number mattresses

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.