In this review, we will be comparing KUBE 8b and Sub 3, two Powered Subwoofer speakers from KEF and Dynaudio. 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 8b and Dynaudio Sub 3 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 8band Dynaudio Sub 3 have a single woofer setup however the KEF KUBE 8b's woofer is 8-inch whereas the Dynaudio Sub 3 features a 9.5-inch woofer.
Frequency Response
KUBE 8b has a frequency range of 34-140 Hz whereas Sub 3 has a frequency range of 22-175 Hz. With a minimum frequency of 22Hz, the Sub 3 can go significantly deeper on the low side and provide stronger bass compared to the KUBE 8b's min frequency of 34Hz.
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 KEF KUBE 8b and Dynaudio Sub 3 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 KEF KUBE 8b's and Dynaudio Sub 3's external dimensions. 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) whereas Dynaudio Sub 3 has external dimensions of 277.0 x 269.0 x 366.0mm (10-7/8 x 10-9/16 x 14-3/8inch).
Dynaudio Sub 3 is 27mm narrower and 17mm shorter than KEF KUBE 8b but it is also 27mm deeper.
Below you can see the front view size comparison of KEF KUBE 8b and Dynaudio Sub 3 in scale.
Comparison image of KEF KUBE 8b and Dynaudio Sub 3 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 8b is approximately 1003.4cm2 / 155.5inch2 and base area of the Dynaudio Sub 3 is approximately 984.5cm2 / 152.6inch2. The KUBE 8b requires 2% more surface area than the Sub 3 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 8b weighs 11.36kg / 25lbs and the Dynaudio Sub 3 weighs 10.50kg / 23.1lbs. This makes the KUBE 8b 8% heavier than the Sub 3.
Here is a comparison of how KUBE 8b and Sub 3'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 8b?
Here are the items that are included inside the box of KUBE 8b:
- 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 Dynaudio Sub 3?
Here are the items that come with the Sub 3:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- Owners Manual
- Quick Start Guide
- Warranty Extension Card
 Price per pair* |
600USD
vs
1399USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
9.5 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
22 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
175 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
277mm
vs
294mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
984cm2
vs
1003cm2
|
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.
Near-identical footprints. Dynaudio Sub 3 stands 27mm further into the room. KEF KUBE 8b is 17mm taller.
| General |
KEF KUBE 8b |
Dynaudio Sub 3 |
| Brand |
KEF |
Dynaudio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
300 watts |
| Frequency Response |
34-140 Hz |
22-175 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
9.5" |
| Woofer Composition |
|
Magnesium Silicate Polymer |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
50-150Hz and 60Hz/80Hz/FlatHz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
294.0mm (11.6") |
277.0mm (10.9") |
| Width |
296.0mm (11.7") |
269.0mm (10.6") |
| Depth |
339.0mm (13.3") |
366.0mm (14.4") |
| Weight |
11.36kg (25lbs) |
10.50kg (23.1lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 Years |
Different price classes - Dynaudio Sub 3 costs roughly 2.3x what KEF KUBE 8b does. Before paying it, read the note below about two smaller subwoofers.
| Area | Better | Why |
|---|
| Bass depth | B | Dynaudio Sub 3 goes deeper - 22Hz against 34Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | B | Dynaudio Sub 3 moves more air: 9.5" against 8" is 1.41x the cone area, not the 1.19x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | evenly matched | Both are sealed designs, so they roll off in much the same way. |
| Warranty | B | Dynaudio Sub 3 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 | KEF KUBE 8b costs less - $600 against $1,399, about 57% less. |
A KEF KUBE 8b B Dynaudio Sub 3
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?
The usual trade-off: Dynaudio Sub 3 measures better, KEF KUBE 8b costs about 57% less. In a normal room, placement will make a bigger difference than the gap between these two. Two small subwoofers beat one big one in most rooms - a pair evens out the room modes in a way no single box can, whatever its specs. At $600 each, two KEF KUBE 8b cost about $1,200 against $1,399 for one of the other, which is worth a thought.
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.