In this review, we will be comparing SW-15 and KF92, 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 KF92 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.Wharfedale SW-15 and KEF KF92 have a totally different setup: the Wharfedale SW-15 features 1 x 15-inch drivers whereas the KF92 features 2 x 9-inch drivers.
Frequency Response
SW-15 has a frequency range of 30-120 Hz whereas KF92 has a frequency range of 11-200 Hz. With a minimum frequency of 11Hz, the KF92 can go significantly deeper on the low side and provide stronger bass compared to the SW-15's min frequency of 30Hz.
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 KF92 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.
New
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 KF92'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 KF92 has external dimensions of 353.0 x 331.0 x 362.0mm (13-7/8 x 13 x 14-1/4inch).
Wharfedale SW-15 is clearly the larger of the two speakers. Its body is 162mm wider, 217mm taller and 253mm deeper than KEF KF92.
Below you can see the front view size comparison of Wharfedale SW-15 and KEF KF92 in scale.
Comparison image of Wharfedale SW-15 and KEF KF92 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 Wharfedale SW-15 is approximately 3032.0cm2 / 470.0inch2 and base area of the KEF KF92 is approximately 1198.2cm2 / 185.7inch2. The SW-15 requires 153% more surface area than the KF92 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 KF92 weighs 20.05kg / 44.1lbs. This makes the SW-15 57% heavier than the KF92.
Here is a comparison of how SW-15 and KF92'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 KF92?
Here are the items that come with the KF92:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 Woofer Size |
15 inches
vs
9 inches
|
Larger woofer |
 Price per pair* |
1199USD
vs
2000USD
|
costs less (*prices may change depending on the seller, location and time) |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
11 Hz
vs
30 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
353mm
vs
570mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1198cm2
vs
3032cm2
|
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.
Wharfedale SW-15 needs about 153% more floor area. Wharfedale SW-15 stands 253mm further into the room. Wharfedale SW-15 is 217mm taller.
| General |
Wharfedale SW-15 |
KEF KF92 |
| Brand |
Wharfedale |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
400 watts |
1000 watts |
| Frequency Response |
30-120 Hz |
11-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
400-watt RMS |
1000-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
15" |
9" |
| Woofer Composition |
Paper |
Hybrid aluminum |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
n/a |
Physical Specs |
|
|
| Height |
570.0mm (22.4") |
353.0mm (13.9") |
| Width |
493.0mm (19.4") |
331.0mm (13") |
| Depth |
615.0mm (24.2") |
362.0mm (14.3") |
| Weight |
31.57kg (69.5lbs) |
20.05kg (44.1lbs) |
| 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 | B | KEF KF92 goes deeper - 11Hz against 30Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | B | KEF KF92 has the bigger amplifier - 1000W against 400W RMS, about 4dB 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 2 x 9" is 1.39x the cone area, not the 1.18x 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 KF92 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 | B | KEF KF92 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 KF92 is about 76% 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 | A | Wharfedale SW-15 costs less - $1,199 against $2,000, about 40% less. |
A Wharfedale SW-15 B KEF KF92
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 KF92 is ahead, but on only 1 of the measured areas, and it costs about 67% more. Wharfedale SW-15 is the sensible buy unless your room is large enough to need the extra. 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 KF92 is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, KEF KF92 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.