In this review, we will be comparing Gravis I 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 I and Polk Monitor XT12 first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the Sonus faber Gravis I and Polk Monitor XT12 compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
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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 Iand Polk Monitor XT12 have a single woofer setup however the Sonus faber Gravis I's woofer is 8-inch whereas the Polk Monitor XT12 features a 12-inch woofer.
Frequency Response
Gravis I has a frequency range of 30-120 Hz whereas Monitor XT12 has a frequency range of 24-160 Hz. With a minimum frequency of 24Hz, the Monitor XT12 can go significantly deeper on the low side and provide stronger bass compared to the Gravis I'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 Sonus faber Gravis I has a Acoustic Suspension type cabinet. 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. 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
Size of a speaker can sometimes become 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 I's and Polk Monitor XT12's external dimensions. Sonus faber Gravis I has external dimensions of 337.0 x 286.0 x 340.0mm ( 13-1/4inch x 11-1/4inch x 13-3/8inch ) 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 122mm wider, 81mm taller and 145mm deeper than Sonus faber Gravis I.
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 I is approximately 972.4cm2 / 150.7inch2 and base area of the Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2. The Gravis I requires 51% 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 I weighs 14.55kg / 32lbs and the Polk Monitor XT12 weighs 17.73kg / 39lbs. This makes the Monitor XT12 22% heavier than the Gravis I.
Here is a comparison of how Gravis I 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 I?
Here are the items that are included inside the box of Gravis I:
Powered subwoofer6-feet AC power cord33-feet Speakon cableOwners ManualEnvironmental Information
What's in the Box of Polk Monitor XT12?
Here are the items that come with the Monitor XT12:
Black powered subwoofer6.5-feet AC power cordGrilleOwners ManualOnline registration card
 Height |
337mm
vs
418mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
972cm2
vs
1978cm2
|
Takes less floor space |
 Driver Setup |
1-way
vs
-way
|
Have a dedicated mid-range driver |
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
30 Hz
|
Generates deeper bass |
 High Frequency Response |
160k Hz
vs
120k Hz
|
Generates higher frequency |
 Price per pair* |
399USD
vs
999USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Sonus faber Gravis I |
Polk Monitor XT12 |
| Brand |
Sonus Faber |
Polk Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
150 watts |
50 watts |
| Frequency Response |
30-120 Hz |
24-160 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
150-watt RMS |
50-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
Treated Paper |
Bi-laminate paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
bottom |
front |
Physical Specs |
|
|
| Height |
337.0mm (13.3") |
418.0mm (16.5") |
| Width |
286.0mm (11.3") |
408.0mm (16.1") |
| Depth |
340.0mm (13.4") |
485.0mm (19.1") |
| Weight |
14.55kg (32lbs) |
17.73kg (39lbs) |
| Enclosure |
Acoustic Suspension |
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 |