In this review, we will be comparing Gravis II and Monitor XT12, two Powered Subwoofer speakers from Sonus faber 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 Sonus faber Gravis II 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.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both Sonus faber Gravis IIand Polk Monitor XT12 have a single woofer setup however the Sonus faber Gravis II's woofer is 10-inch whereas the Polk Monitor XT12 features a 12-inch woofer.
Frequency Response
Gravis II has a frequency range of 25-120 Hz whereas Monitor XT12 has a frequency range of 24-160 Hz. With a minimum frequency of 24Hz, the Monitor XT12 can go slightly deeper then the Gravis II's min frequency of 25Hz.
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 Sonus faber Gravis II has a Passive Radiator type cabinet. Passive Radiator type subwoofers sports a non-powered cone that moves in response to the main woofer to move air out in order to generate stronger bass in a smaller body compared to ported or sealed designs. On the other hand the Polk Monitor XT12 have Bass Reflex type enclosure. 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 Sonus faber Gravis II's and Polk Monitor XT12's external dimensions. Sonus faber Gravis II has external dimensions of 407.0 x 358.0 x 435.0mm (16inch x 14-1/16inch x 17-1/8inch) 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 clearly the larger of the two speakers. Its body is 50mm wider, 11mm taller and 50mm deeper than Sonus faber Gravis II.
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 Sonus faber Gravis II is approximately 1557.3cm2 / 241.4inch2 and base area of the Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2. The Gravis II requires 21% 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 Sonus faber Gravis II weighs 21.50kg / 47.3lbs and the Polk Monitor XT12 weighs 17.73kg / 39lbs. This makes the Gravis II 21% heavier than the Monitor XT12.
Here is a comparison of how Gravis II and Monitor XT12's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of Sonus faber Gravis II?
Here are the items that are included inside the box of Gravis II:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- 33-feet Speakon cable
- Owners Manual
- Environmental Information
What's in the Box of Polk Monitor XT12?
Here are the items that come with the Monitor XT12:
- Black powered subwoofer
- 6.5-feet AC power cord
- Grille
- Owners Manual
- Online registration card
 Passive Radiator |
2 x 10-inch
vs
None
|
Increases the bass performance |
 Height |
407mm
vs
418mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1557cm2
vs
1978cm2
|
Takes less floor space |
 Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
25 Hz
|
Generates deeper bass |
 High Frequency Response |
160k Hz
vs
120k Hz
|
Generates higher frequency |
 Price per pair* |
399USD
vs
1499USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Sonus faber Gravis II |
Polk Monitor XT12 |
| Brand |
Sonus faber |
Polk Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
350 watts |
50 watts |
| Frequency Response |
25-120 Hz |
24-160 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
350-watt RMS |
50-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
12" |
| Woofer Composition |
Treated Paper |
Bi-laminate paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
407.0mm (16") |
418.0mm (16.5") |
| Width |
358.0mm (14.1") |
408.0mm (16.1") |
| Depth |
435.0mm (17.1") |
485.0mm (19.1") |
| Weight |
21.50kg (47.3lbs) |
17.73kg (39lbs) |
| Enclosure |
Passive Radiator |
Bass Reflex |
| Available Colors |
Piano Black,Matte White |
n/a |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Yr/3 Yr registered |
3 Years |
| Labor Warranty |
2 Yr/3 Yr registered |
3 Years |