In this review, we will be comparing PSW10 and KUBE 8b, 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 PSW10 and KEF KUBE 8b first before getting into our more detailed comparison.
The sections below take each area in turn: driver and amplifier, frequency response, physical size and connectivity.
Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both Polk PSW10and KEF KUBE 8b have a single woofer setup however the Polk PSW10's woofer is 10-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
PSW10 has a frequency range of 40-160 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 34Hz, the KUBE 8b can go significantly deeper on the low side and provide stronger bass compared to the PSW10's min frequency of 40Hz.
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 PSW10 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 8b 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
The size of a speaker can sometimes be 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 PSW10's and KEF KUBE 8b's external dimensions. Polk PSW10 has external dimensions of 366.0 x 356.0 x 412.0mm (14-3/8 x 14 x 16-3/16inch) whereas 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).
Polk PSW10 is clearly the larger of the two speakers. Its body is 60mm wider, 72mm taller and 73mm deeper than KEF KUBE 8b.
Below you can see the front view size comparison of Polk PSW10 and KEF KUBE 8b in scale.
Comparison image of Polk PSW10 and KEF KUBE 8b 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 Polk PSW10 is approximately 1466.7cm2 / 227.3inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The PSW10 requires 46% more surface area than the KUBE 8b 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 PSW10 weighs 11.82kg / 26lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the PSW10 4% heavier than the KUBE 8b.
Here is a comparison of how PSW10 and KUBE 8b'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 PSW10?
Here are the items that are included inside the box of PSW10:
- Black powered subwoofer
- Grille
- Owners Manual
- Online registration card
What's in the Box of KEF KUBE 8b?
Here are the items that come with the KUBE 8b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 Woofer Size |
10 inches
vs
8 inches
|
Larger woofer |
 High Frequency Response |
160 Hz
vs
140 Hz
|
Generates higher frequency |
 Price per pair* |
249USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
| Low Frequency Response |
34 Hz
vs
40 Hz
|
Generates deeper bass |
 Height |
294mm
vs
366mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
1466cm2
|
Takes less floor space |
Size, drawn to scale
Both subwoofers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same floor and pushed back to the same wall, so the bigger one visibly takes more of the room.
Polk PSW10 needs about 46% more floor area. Polk PSW10 stands 73mm further into the room. Polk PSW10 is 72mm taller.
| General |
Polk Audio PSW10 |
KEF KUBE 8b |
| Brand |
Polk Audio |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
50 watts |
300 watts |
| Frequency Response |
40-160 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
50-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
8" |
| Woofer Composition |
Polymer Composite |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
366.0mm (14.4") |
294.0mm (11.6") |
| Width |
356.0mm (14") |
296.0mm (11.7") |
| Depth |
412.0mm (16.2") |
339.0mm (13.3") |
| Weight |
11.82kg (26lbs) |
11.36kg (25lbs) |
| 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 |
A ported subwoofer against a sealed one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | B | KEF KUBE 8b goes deeper - 34Hz against 40Hz. A real difference, though most music has little content below 40Hz. |
| Amplifier power | B | KEF KUBE 8b has the bigger amplifier - 300W against 50W RMS, about 7.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Polk PSW10 moves more air: 10" against 8" is 1.56x the cone area, not the 1.25x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | Polk PSW10 is ported - a ported box gives more output low down for its size, at the cost of a steeper roll-off below tuning; KEF KUBE 8b is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Speaker-level inputs | A | Polk PSW10 takes a speaker-level connection as well as line level. That is what lets it work with an integrated amplifier or a vintage receiver that has no subwoofer output at all. |
| Cabinet size | depends | KEF KUBE 8b is about 45% smaller by volume. In a subwoofer that is a real trade rather than a preference: box volume is how you get output low down without a bigger amplifier. |
| Warranty | A | Polk PSW10 carries 3 years on parts against 2 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | A | Polk PSW10 costs less - $249 against $600, about 59% less. |
A Polk PSW10 B KEF KUBE 8b
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both subwoofers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Polk PSW10 has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is. Films or music? If this is mainly a home cinema, Polk PSW10 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 8b is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, Polk PSW10 is the only one of these two you can connect at all.
One thing outweighs everything above: where the subwoofer stands. Room modes can add or remove 10dB or more at a given seat, which is far larger than any difference on this page. Before spending more, try the sub in two or three positions - the crawl test, where you put it in the listening seat and crawl the room to find where the bass sounds best, costs nothing and usually beats an upgrade.