In this review, we will be comparing Alpha S8 and KUBE 10b, two Powered Subwoofer speakers from PSB and KEF. 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 PSB Alpha S8 and KEF KUBE 10b first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the PSB Alpha S8 and KEF KUBE 10b 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.Both PSB Alpha S8and KEF KUBE 10b have a single woofer setup however the PSB Alpha S8's woofer is 8-inch whereas the KEF KUBE 10b features a 10-inch woofer.
Frequency Response
Alpha S8 has a frequency range of 35-150 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 24Hz, the KUBE 10b can go significantly deeper on the low side and provide stronger bass compared to the Alpha S8's min frequency of 35Hz.
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 PSB Alpha S8 has a Bass Reflex type cabinet. 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. On the other hand the KEF KUBE 10b have Acoustic Suspension type enclosure. 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.
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 PSB Alpha S8's and KEF KUBE 10b's external dimensions. PSB Alpha S8 has external dimensions of 318.0 x 293.0 x 413.0mm ( 12-1/2 x 11-1/2 x 16-1/4inch) whereas KEF KUBE 10b has external dimensions of 372.0 x 356.0 x 397.0mm ( 14-5/8 x 14 x 15-5/8inch) .
PSB Alpha S8 is 63mm narrower and 54mm shorter than KEF KUBE 10b but it is also 16mm deeper.
Below you can see the front view size comparison of PSB Alpha S8 and KEF KUBE 10b in scale.
Comparison image of PSB Alpha S8 and KEF KUBE 10b 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 PSB Alpha S8 is approximately 1210.1cm2 / 187.6inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The Alpha S8 requires 14% less surface area than the KUBE 10b which gives it a small advantage 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 PSB Alpha S8 weighs 9.55kg / 21lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the KUBE 10b 83% heavier than the Alpha S8.
Here is a comparison of how Alpha S8 and KUBE 10b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of PSB Alpha S8?
Here are the items that are included inside the box of Alpha S8:
Powered subwooferGrille5-feet AC power cord4 Rubber feet4 Spike feet4 Hex-nutsQuick Start GuideImportant Safety InstructionsWarranty Information
What's in the Box of KEF KUBE 10b?
Here are the items that come with the KUBE 10b:
Powered subwoofer6.5-feet AC power cordSpeaker-level input blockUser ManualImportant Safety InformationWarranty Information
 High Frequency Response |
150k Hz
vs
140k Hz
|
Generates higher frequency |
 Height |
318mm
vs
372mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1210cm2 (293x413mm)
vs
1413cm2 (356x397mm)
|
Takes less floor space |
 Price per pair* |
549USD
vs
750USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
10 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
35 Hz
|
Generates deeper bass |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| General |
PSB Alpha S8 |
KEF KUBE 10b |
| Brand |
PSB |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
150 watts |
300 watts |
| Frequency Response |
35-150 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
150-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
10" |
| Woofer Composition |
Polypropylene |
Not given |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
318.0mm (12.5") |
372.0mm (14.6") |
| Width |
293.0mm (11.5") |
356.0mm (14") |
| Depth |
413.0mm (16.3") |
397.0mm (15.6") |
| Weight |
9.55kg (21lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Bass Reflex |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
1 Year |
2 Years |
| Labor Warranty |
1 Year |
2 Years |