In this review, we will be comparing Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer and KF92, two Powered Subwoofer speakers from Aperion 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 Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 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.Both Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwooferand KEF KF92 have a double woofer setup however the Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer's woofer is 15-inch whereas the KEF KF92 features a 9-inch woofer.
Frequency Response
Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer has a frequency range of 17-180 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 Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer's min frequency of 17Hz.
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
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer
High Frequency
Subwoofer Speakers
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer
Cabinet Type
The Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 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.
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 Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer's and KEF KF92's external dimensions. Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer has external dimensions of 1099.8 x 551.2 x 299.7mm (43.3 x 21.7 x 11.8inch) whereas KEF KF92 has external dimensions of 353.0 x 331.0 x 362.0mm (13-7/8 x 13 x 14-1/4inch).
KEF KF92 is 220.2mm narrower and 746.8mm shorter than Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer but it is also 62.3mm deeper.
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.
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer needs about 38% more floor or shelf area. KEF KF92 is 62mm deeper, so it stands that much further out from the wall. Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer is 747mm 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 Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer is approximately 1651.9cm2 / 256.0inch2 and base area of the KEF KF92 is approximately 1198.2cm2 / 185.7inch2. The Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer requires 38% 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 Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer weighs 71.53kg / 157.4lbs and the KEF KF92 weighs 20.05kg / 44.1lbs. This makes the Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 257% heavier than the KF92.
Here is a comparison of how Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer and KF92's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer
 Woofer Size |
15 inches
vs
9 inches
|
Larger woofer |
| Low Frequency Response |
11 Hz
vs
17 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
180 Hz
|
Generates higher frequency |
 Height |
353mm
vs
1099mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1198cm2
vs
1651cm2
|
Takes less floor space |
 Price per pair* |
2000USD
vs
4499USD
|
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.
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer needs about 38% more floor area. KEF KF92 stands 62mm further into the room. Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer is 747mm taller.
| General |
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer |
KEF KF92 |
| Brand |
Aperion |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1300 watts |
1000 watts |
| Impedance |
4 ohms |
n/a |
| Frequency Response |
17-180 Hz |
11-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1300-watt RMS |
1000-watt RMS |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
15" |
9" |
| Woofer Composition |
|
Hybrid aluminum |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-160 Hz |
n/a |
Physical Specs |
|
|
| Height |
1099.8mm (43.3") |
353.0mm (13.9") |
| Width |
551.2mm (21.7") |
331.0mm (13") |
| Depth |
299.7mm (11.8") |
362.0mm (14.3") |
| Weight |
71.53kg (157.4lbs) |
20.05kg (44.1lbs) |
| Enclosure |
Bass Reflex |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
2 Years |
| Labor Warranty |
|
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 17Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer has the bigger amplifier - 1300W against 1000W RMS, about 1.1dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer moves more air: 2 x 15" against 2 x 9" is 2.78x the cone area, not the 1.67x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 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. |
| Cabinet size | depends | KEF KF92 is about 77% 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. |
| Price | B | KEF KF92 costs less - $2,000 against $4,499, about 56% less. |
A Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 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?
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer is ahead, but on only 1 of the measured areas, and it costs about 125% more. KEF KF92 is the sensible buy unless your room is large enough to need the extra. Films or music? If this is mainly a home cinema, Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 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. 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 $2,000 each, two KEF KF92 cost about $4,000 against $4,499 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.