In this review, we will be comparing KUBE 10b and ProSub 800, two Powered Subwoofer speakers from KEF and Definitive Technology. 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 10b and Definitive ProSub 800 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 KEF KUBE 10band Definitive ProSub 800 have a single woofer setup however the KEF KUBE 10b's woofer is 10-inch whereas the Definitive ProSub 800 features a 8-inch woofer.
Frequency Response
KUBE 10b has a frequency range of 24-140 Hz whereas ProSub 800 has a frequency range of 20-150 Hz. With a minimum frequency of 20Hz, the ProSub 800 can go slightly deeper then the KUBE 10b's min frequency of 24Hz.
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 10b 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 Definitive ProSub 800 have Passive Radiator type enclosure. Passive Radiator type subwoofers sports a non-powered cone that moves in response to the main woofer to move air out in order to generate stronger bass in a smaller body compared to ported or sealed 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 KEF KUBE 10b's and Definitive ProSub 800's external dimensions. KEF KUBE 10b has external dimensions of 372.0 x 356.0 x 397.0mm (14-5/8 x 14 x 15-5/8inch) whereas Definitive ProSub 800 has external dimensions of 328.0 x 262.0 x 423.0mm (12-7/8 x 10-5/16 x 16-5/8inch).
Definitive ProSub 800 is 94mm narrower and 44mm shorter than KEF KUBE 10b but it is also 26mm deeper.
Below you can see the front view size comparison of KEF KUBE 10b and Definitive ProSub 800 in scale.
Comparison image of KEF KUBE 10b and Definitive ProSub 800 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 10b is approximately 1413.3cm2 / 219.1inch2 and base area of the Definitive ProSub 800 is approximately 1108.3cm2 / 171.8inch2. The KUBE 10b requires 28% more surface area than the ProSub 800 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 10b weighs 17.50kg / 38.5lbs and the Definitive ProSub 800 weighs 11.82kg / 26lbs. This makes the KUBE 10b 48% heavier than the ProSub 800.
Here is a comparison of how KUBE 10b and ProSub 800'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 10b?
Here are the items that are included inside the box of KUBE 10b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
What's in the Box of Definitive ProSub 800?
Here are the items that come with the ProSub 800:
- 8-inch Powered subwoofer
- Detachable grille (installed)
- 7-feet AC power cord
- Owners Manual
- Online Product Registration card
 Woofer Size |
10 inches
vs
8 inches
|
Larger woofer |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| Low Frequency Response |
20 Hz
vs
24 Hz
|
Generates deeper bass |
 High Frequency Response |
150 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
328mm
vs
372mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1108cm2
vs
1413cm2
|
Takes less floor space |
 Price per pair* |
399USD
vs
750USD
|
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.
KEF KUBE 10b needs about 28% more floor area. Definitive ProSub 800 stands 26mm further into the room. KEF KUBE 10b is 44mm taller.
| General |
KEF KUBE 10b |
Definitive Technology ProSub 800 |
| Brand |
KEF |
Definitive Technology |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
300 watts |
| Frequency Response |
24-140 Hz |
20-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
8" |
| Woofer Composition |
|
Polymer |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
40-150 Hz and 80 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
372.0mm (14.6") |
328.0mm (12.9") |
| Width |
356.0mm (14") |
262.0mm (10.3") |
| Depth |
397.0mm (15.6") |
423.0mm (16.7") |
| Weight |
17.50kg (38.5lbs) |
11.82kg (26lbs) |
| Enclosure |
Acoustic Suspension |
Passive Radiator |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 Years |
A sealed subwoofer against a passive radiator 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 | Definitive ProSub 800 goes deeper - 20Hz against 24Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | A | KEF KUBE 10b 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 | KEF KUBE 10b is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; Definitive ProSub 800 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet. 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 | B | Definitive ProSub 800 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. |
| Wireless option | depends | Only KEF KUBE 10b offers a wireless link (as a paid option). It decides where the sub can go if you cannot run a cable, and is worth nothing if you can. |
| Phase control | A | KEF KUBE 10b has a phase control. Without one, the only way to fix a cancellation at the crossover is to move the box. |
| Cabinet size | depends | Definitive ProSub 800 is about 31% 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 | B | Definitive ProSub 800 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 | B | Definitive ProSub 800 costs less - $399 against $750, about 47% less. |
A KEF KUBE 10b B Definitive ProSub 800
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?
Definitive ProSub 800 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, Definitive ProSub 800 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 10b is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, Definitive ProSub 800 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.