In this review, we will be comparing SubSeries 250 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 SubSeries 250 and KEF KUBE 10b 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.PSB SubSeries 250and KEF KUBE 10b have the same driver set up: Both subwoofers have 1 x 10" drivers.
Frequency Response
SubSeries 250 has a frequency range of 25-150 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 24Hz, the KUBE 10b can go slightly deeper then the SubSeries 250's min frequency of 25Hz.
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
Both PSB SubSeries 250 and KEF KUBE 10b have Acoustic Suspension type cabinets. 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 PSB SubSeries 250's and KEF KUBE 10b's external dimensions. PSB SubSeries 250 has external dimensions of 362.0 x 348.0 x 397.0mm (14-1/4 x 13-11/16 x 15-5/8inch) 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).
Below you can see the front view size comparison of PSB SubSeries 250 and KEF KUBE 10b in scale.
Comparison image of PSB SubSeries 250 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 SubSeries 250 is approximately 1381.6cm2 / 214.1inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The SubSeries 250 requires 2% 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 SubSeries 250 weighs 19.09kg / 42lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the SubSeries 250 9% heavier than the KUBE 10b.
Here is a comparison of how SubSeries 250 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 SubSeries 250?
Here are the items that are included inside the box of SubSeries 250:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- Quick Start Guide
- Important Safety Instructions
- Warranty Information
What's in the Box of KEF KUBE 10b?
Here are the items that come with the KUBE 10b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 High Frequency Response |
150 Hz
vs
140 Hz
|
Generates higher frequency |
 Base Surface Area |
1381cm2
vs
1413cm2
|
Takes less floor space |
 Low Frequency Response |
24 Hz
vs
25 Hz
|
Generates deeper bass |
 Price per pair* |
750USD
vs
999USD
|
costs less (*prices may change depending on the seller, location and time) |
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.
Near-identical footprints.
| General |
PSB SubSeries 250 |
KEF KUBE 10b |
| Brand |
PSB |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
200 watts |
300 watts |
| Frequency Response |
25-150 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
200-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
10" |
| Woofer Composition |
Polypropylene |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
50-150 Hz and 80 Hz |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
372.0mm (14.6") |
372.0mm (14.6") |
| Width |
348.0mm (13.7") |
356.0mm (14") |
| Depth |
397.0mm (15.6") |
397.0mm (15.6") |
| Weight |
19.09kg (42lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
1 Year |
2 Years |
| Labor Warranty |
1 Year |
2 Years |
No single best subwoofer here. Your room, where the box can physically go, and whether this is mainly for films or mainly for music will settle it long before the specs do.
| Area | Better | Why |
|---|
| Bass depth | evenly matched | Effectively the same reach (25Hz vs 24Hz). |
| Amplifier power | B | KEF KUBE 10b has the bigger amplifier - 300W against 200W RMS, about 1.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | evenly matched | Near-identical radiating area (10" against 10"). |
| Enclosure | evenly matched | Both are sealed designs, so they roll off in much the same way. |
| Speaker-level inputs | A | PSB SubSeries 250 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. |
| Warranty | B | KEF KUBE 10b carries 2 years on parts against 1 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | B | KEF KUBE 10b costs less - $750 against $999, about 25% less. |
A PSB SubSeries 250 B KEF KUBE 10b
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?
KEF KUBE 10b has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is. Check your amplifier first: if it has no subwoofer or preamp output, PSB SubSeries 250 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.