In this review, we will be comparing Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer and Monitor XT12, two Powered Subwoofer speakers from Aperion and Polk Audio. 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 Polk Monitor XT12 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.Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer and Polk Monitor XT12 have a totally different setup: the Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer features 2 x 15-inch drivers whereas the Monitor XT12 features 1 x 12-inch drivers.
Frequency Response
Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer has a frequency range of 17-180 Hz whereas Monitor XT12 has a frequency range of 24-160 Hz. With a minimum frequency of 17Hz, the Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer can go significantly deeper on the low side and provide stronger bass compared to the Monitor XT12's min frequency of 24Hz.
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
Both Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer and Polk Monitor XT12 have Bass Reflex type cabinets. 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.
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 Polk Monitor XT12'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 Polk Monitor XT12 has external dimensions of 418.0 x 408.0 x 485.0mm (16-7/16inch x 16-1/16inch x 19-1/16inch).
Polk Monitor XT12 is 143.2mm narrower and 681.8mm shorter than Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer but it is also 185.3mm 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.
Polk Monitor XT12 needs about 20% more floor or shelf area. Polk Monitor XT12 is 185mm deeper, so it stands that much further out from the wall. Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer is 682mm 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 Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2. The Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer requires 17% less surface area than the Monitor XT12 which gives it a small advantage 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 Polk Monitor XT12 weighs 17.73kg / 39lbs. This makes the Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer 303% heavier than the Monitor XT12.
Here is a comparison of how Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer and Monitor XT12'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
12 inches
|
Larger woofer |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
17 Hz
vs
24 Hz
|
Generates deeper bass |
 High Frequency Response |
180 Hz
vs
160 Hz
|
Generates higher frequency |
 Base Surface Area |
1651cm2
vs
1978cm2
|
Takes less floor space |
 Height |
418mm
vs
1099mm
|
Easier to fit in smaller spaces |
 Price per pair* |
399USD
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.
Polk Monitor XT12 needs about 20% more floor area. Polk Monitor XT12 stands 185mm further into the room. Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer is 682mm taller.
| General |
Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer |
Polk Monitor XT12 |
| Brand |
Aperion |
Polk Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1300 watts |
50 watts |
| Impedance |
4 ohms |
n/a |
| Frequency Response |
17-180 Hz |
24-160 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1300-watt RMS |
50-watt RMS |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
15" |
12" |
| Woofer Composition |
|
Bi-laminate paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-160 Hz |
n/a |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
1099.8mm (43.3") |
418.0mm (16.5") |
| Width |
551.2mm (21.7") |
408.0mm (16.1") |
| Depth |
299.7mm (11.8") |
485.0mm (19.1") |
| Weight |
71.53kg (157.4lbs) |
17.73kg (39lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
3 Years |
| Labor Warranty |
|
3 Years |
Two quite different sizes of subwoofer. Room volume decides this more than anything else on the page: a big driver in a small room is wasted, and a small one in a large room is worked to death.
| Area | Better | Why |
|---|
| Bass depth | A | Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer goes deeper - 17Hz against 24Hz. 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 50W RMS, about 14.1dB 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 12" is 3.13x the cone area, not the 1.77x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | evenly matched | Both are ported designs, so they roll off in much the same way. |
| Cabinet size | depends | Polk Monitor XT12 is about 54% 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 | Polk Monitor XT12 costs less - $399 against $4,499, about 91% less. |
A Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer B Polk Monitor XT12
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: Aperion Bravus III B215S Dual 15" Slim Cinema Powered Subwoofer measures better, Polk Monitor XT12 costs about 91% 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 $399 each, two Polk Monitor XT12 cost about $798 against $4,499 for one of the other, which is worth a thought. If placement is the constraint - a corner, behind a sofa, under a desk - Polk Monitor XT12 is the one that will actually go there, and a well-placed small subwoofer beats a badly-placed big one every time.
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.