In this review, we will be comparing KUBE 8b and S8, two Powered Subwoofer speakers from KEF and Audioengine. Being Powered subwoofers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them. Let's have a brief look at the main features of KEF KUBE 8b and Audioengine S8 first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the KEF KUBE 8b and Audioengine S8 compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.KEF KUBE 8band Audioengine S8 have the same driver set up: Both subwoofers have 1 x 8" drivers.
Frequency Response
KUBE 8b has a frequency range of 34-140 Hz whereas S8 has a frequency range of 27-180 Hz. With a minimum frequency of 27Hz, the S8 can go significantly deeper on the low side and provide stronger bass compared to the KUBE 8b's min frequency of 34Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Subwoofer class in our database.
Low Frequency
Subwoofer Speakers
High Frequency
Subwoofer Speakers
Cabinet Type
The KEF KUBE 8b has a Acoustic Suspension type cabinet. Acoustic Suspension aka Sealed type subwoofers have enclosures that are sealed hence no ports or holes exists on the cabinet. Sealed designs helps to provide more accurate and tight bass responses compared to ported designs. On the other hand the Audioengine S8 have Bass Reflex type enclosure. Bass Reflex type subwoofers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed designs.
Physical Specs
Size of a speaker can sometimes become an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare KEF KUBE 8b's and Audioengine S8's external dimensions. KEF KUBE 8b has external dimensions of 294.0 x 296.0 x 339.0mm ( 11-9/16 x 11-5/8 x 13-5/16inch) whereas Audioengine S8 has external dimensions of 334.0 x 293.0 x 337.0mm ( 13-1/8 x 11-1/2 x 13-1/4inch) .
Audioengine S8 is 3mm narrower and 2mm less deeper than KEF KUBE 8b but it is also 40mm taller.
Below you can see the front view size comparison of KEF KUBE 8b and Audioengine S8 in scale.
Comparison image of KEF KUBE 8b and Audioengine S8 Size and External Dimensions
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2 and base area of the Audioengine S8 is approximately 987.4cm2 / 153.0inch2. The KUBE 8b requires 2% more surface area than the S8 which gives it a small disadvantage on placement in tight spaces.
Weight Comparison The weight of a subwoofer may become an important factor if you need to move and reposition the unit often to find the optimal positioning, also known as 'Subwoofer Crawling'. The KEF KUBE 8b weighs 11.36kg / 25lbs and the Audioengine S8 weighs 13.64kg / 30lbs. This makes the S8 20% heavier than the KUBE 8b.
Here is a comparison of how KUBE 8b and S8's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of KEF KUBE 8b?
Here are the items that are included inside the box of KUBE 8b:
Powered subwoofer6.5-feet AC power cordSpeaker-level input blockUser ManualImportant Safety InformationWarranty Information
What's in the Box of Audioengine S8?
Here are the items that come with the S8:
Powered subwoofer6-feet AC power cord6.5-feet Stereo RCA cable6.5-feet Stereo minijack audio cableCloth subwoofer bagCloth cable bagQuick Start GuideAudioengine brochure
 Height |
294mm
vs
334mm
|
Easier to fit in smaller spaces |
 Low Frequency Response |
27 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
180k Hz
vs
140k Hz
|
Generates higher frequency |
 Base Surface Area |
987cm2 (293x337mm)
vs
1003cm2 (296x339mm)
|
Takes less floor space |
 Price per pair* |
349USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF KUBE 8b |
Audioengine S8 |
| Brand |
KEF |
Audioengine |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
125 watts |
| Frequency Response |
34-140 Hz |
27-180 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
125-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
8" |
| Woofer Composition |
Not given |
Treated paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
front |
bottom |
Physical Specs |
|
|
| Height |
294.0mm (11.6") |
334.0mm (13.1") |
| Width |
296.0mm (11.7") |
293.0mm (11.5") |
| Depth |
339.0mm (13.3") |
337.0mm (13.3") |
| Weight |
11.36kg (25lbs) |
13.64kg (30lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 Years |