In this review, we will be comparing Elite ES8 and KUBE 10b, two Powered Subwoofer speakers from Polk Audio 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 Polk Signature Elite ES8 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 Polk Signature Elite ES8 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 Polk Signature Elite ES8and KEF KUBE 10b have a single woofer setup however the Polk Signature Elite ES8's woofer is 8-inch whereas the KEF KUBE 10b features a 10-inch woofer.
Frequency Response
Elite ES8 has a frequency range of 32-180 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 Elite ES8's min frequency of 32Hz.
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 Polk Signature Elite ES8 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.
Polk Signature Elite ES8 Port
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 Polk Signature Elite ES8's and KEF KUBE 10b's external dimensions. Polk Signature Elite ES8 has external dimensions of 385.0 x 326.0 x 437.0mm ( 15-1/8inch x 12-13/16inch x 17-3/16inch ) 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) .
KEF KUBE 10b is 13mm shorter and 40mm less deeper than Polk Signature Elite ES8 but it is also 30mm wider.
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 Polk Signature Elite ES8 is approximately 1424.6cm2 / 220.8inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The Elite ES8 requires 1% more surface area than the KUBE 10b 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 Polk Signature Elite ES8 weighs 17.73kg / 39lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the Elite ES8 1% heavier than the KUBE 10b.
Here is a comparison of how Elite ES8 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 Polk Signature Elite ES8?
Here are the items that are included inside the box of Elite ES8:
Powered subwooferGrille6-feet AC power cordOwners ManualOnline Product Registration sheet
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 |
180k Hz
vs
140k Hz
|
Generates higher frequency |
 Price per pair* |
449USD
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
32 Hz
|
Generates deeper bass |
 Height |
372mm
vs
385mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1413cm2 (356x397mm)
vs
1424cm2 (326x437mm)
|
Takes less floor space |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| General |
Polk Signature Elite ES8 |
KEF KUBE 10b |
| Brand |
Polk Audio |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
100 watts |
300 watts |
| Frequency Response |
32-180 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
100-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
10" |
| Woofer Composition |
Mineral-filled 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 |
385.0mm (15.2") |
372.0mm (14.6") |
| Width |
326.0mm (12.8") |
356.0mm (14") |
| Depth |
437.0mm (17.2") |
397.0mm (15.6") |
| Weight |
17.73kg (39lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Bass Reflex |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
2 Years |
| Labor Warranty |
3 Years |
2 Years |