In this review, we will be comparing SW-15 and KUBE 8b, two Powered Subwoofer speakers from Wharfedale 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 Wharfedale SW-15 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 Wharfedale SW-15and KEF KUBE 8b have a single woofer setup however the Wharfedale SW-15's woofer is 15-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
SW-15 has a frequency range of 30-120 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 30Hz, the SW-15 can go slightly deeper then 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
The Wharfedale SW-15 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.
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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 Wharfedale SW-15's and KEF KUBE 8b's external dimensions. Wharfedale SW-15 has external dimensions of 570.0 x 493.0 x 615.0mm (22-7/16inch x 19-3/8inch x 24-3/16inch) 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).
Wharfedale SW-15 is clearly the larger of the two speakers. Its body is 197mm wider, 276mm taller and 276mm deeper than KEF KUBE 8b.
Size, drawn to scale
Both speakers 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 surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Wharfedale SW-15 needs about 202% more floor or shelf area. Wharfedale SW-15 is 276mm deeper, so it stands that much further out from the wall. Wharfedale SW-15 is 276mm taller.
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 Wharfedale SW-15 is approximately 3032.0cm2 / 470.0inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The SW-15 requires 202% 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 Wharfedale SW-15 weighs 31.57kg / 69.5lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the SW-15 178% heavier than the KUBE 8b.
Here is a comparison of how SW-15 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 Wharfedale SW-15?
Here are the items that are included inside the box of SW-15:
- Powered subwoofer
- Grille
- 6.5-feet AC power cord
- User-feets 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
 Woofer Size |
15 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
30 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
140 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
294mm
vs
570mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
3032cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
1199USD
|
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.
Wharfedale SW-15 needs about 202% more floor area. Wharfedale SW-15 stands 276mm further into the room. Wharfedale SW-15 is 276mm taller.
| General |
Wharfedale SW-15 |
KEF KUBE 8b |
| Brand |
Wharfedale |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
400 watts |
300 watts |
| Frequency Response |
30-120 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
400-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
15" |
8" |
| Woofer Composition |
Paper |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
570.0mm (22.4") |
294.0mm (11.6") |
| Width |
493.0mm (19.4") |
296.0mm (11.7") |
| Depth |
615.0mm (24.2") |
339.0mm (13.3") |
| Weight |
31.57kg (69.5lbs) |
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 | A | Wharfedale SW-15 goes deeper - 30Hz against 34Hz. A real difference, though most music has little content below 34Hz. |
| Amplifier power | A | Wharfedale SW-15 has the bigger amplifier - 400W against 300W RMS, about 1.2dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Wharfedale SW-15 moves more air: 15" against 8" is 3.52x the cone area, not the 1.88x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | Wharfedale SW-15 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. |
| Cabinet size | depends | KEF KUBE 8b is about 83% 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 | Wharfedale SW-15 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 | KEF KUBE 8b costs less - $600 against $1,199, about 50% less. |
A Wharfedale SW-15 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?
The usual trade-off: Wharfedale SW-15 measures better, KEF KUBE 8b costs about 50% less. In a normal room, placement will make a bigger difference than the gap between these two. Films or music? If this is mainly a home cinema, Wharfedale SW-15 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. 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 $1,199 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.