In this review, we will be comparing Descend DN8 and KUBE 8b, two Powered Subwoofer speakers from Definitive Technology 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 Definitive DN8 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.Definitive DN8and KEF KUBE 8b have the same driver set up: Both subwoofers have 1 x 8" drivers.
Frequency Response
Descend DN8 has a frequency range of 35-200 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 34Hz, the KUBE 8b can go slightly deeper then the Descend DN8'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 Definitive DN8 has a Passive Radiator type cabinet. 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. 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 Definitive DN8's and KEF KUBE 8b's external dimensions. Definitive DN8 has external dimensions of 332.0 x 307.0 x 361.0mm (13-1/16inch x 12-1/16inch x 14-3/16inch) 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).
Definitive DN8 is clearly the larger of the two speakers. Its body is 11mm wider, 38mm taller and 22mm deeper than KEF KUBE 8b.
Below you can see the front view size comparison of Definitive DN8 and KEF KUBE 8b in scale.
Comparison image of Definitive DN8 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 Definitive DN8 is approximately 1108.3cm2 / 171.8inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The Descend DN8 requires 10% 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 Definitive DN8 weighs 12.41kg / 27.3lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the Descend DN8 9% heavier than the KUBE 8b.
Here is a comparison of how Descend DN8 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 Definitive DN8?
Here are the items that are included inside the box of Descend DN8:
- Powered subwoofer
- 6-feet AC power cord
- Owners Manual
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
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 Passive Radiator |
2 x 8-inch
vs
None
|
Increases the bass performance |
 Price per pair* |
499USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
 Low Frequency Response |
34 Hz
vs
35 Hz
|
Generates deeper bass |
 Height |
294mm
vs
332mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
1108cm2
|
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.
Definitive DN8 needs about 10% more floor area. Definitive DN8 stands 22mm further into the room. Definitive DN8 is 38mm taller.
| General |
Definitive Technology Descend DN8 |
KEF KUBE 8b |
| Brand |
Definitive Technology |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
200 watts |
300 watts |
| Frequency Response |
35-200 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
200-watt RMS |
300-watt RMS |
| Watts Peak (Max) |
500-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
8" |
| Woofer Composition |
Polypropylene |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
332.0mm (13.1") |
294.0mm (11.6") |
| Width |
307.0mm (12.1") |
296.0mm (11.7") |
| Depth |
361.0mm (14.2") |
339.0mm (13.3") |
| Weight |
12.41kg (27.3lbs) |
11.36kg (25lbs) |
| Enclosure |
Passive Radiator |
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
2 Years |
| Labor Warranty |
3 Years |
2 Years |
A passive radiator 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 | evenly matched | Effectively the same reach (35Hz vs 34Hz). |
| Amplifier power | B | KEF KUBE 8b 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 (8" against 8"). |
| Enclosure | depends | Definitive DN8 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; 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 | Definitive DN8 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 20% 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 | Definitive DN8 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 | Definitive DN8 costs less - $499 against $600, about 17% less. |
A Definitive DN8 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?
Definitive DN8 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 DN8 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, Definitive DN8 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.