In this review, we will be comparing Monitor XT12 and A120P, two Powered Subwoofer speakers from Polk Audio and JBL. 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 Polk Monitor XT12 and JBL Stage A120P first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the Polk Monitor XT12 and JBL Stage A120P 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.Polk Monitor XT12and JBL Stage A120P have the same driver set up: Both subwoofers have 1 x 12" drivers.
Frequency Response
Monitor XT12 has a frequency range of 24-160 Hz whereas A120P has a frequency range of 32-150 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 A120P's min frequency of 32Hz.
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 Polk Monitor XT12 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 JBL Stage A120P have Bass reflex type enclosure.
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 Polk Monitor XT12's and JBL Stage A120P's external dimensions. 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 ) whereas JBL Stage A120P has external dimensions of 415.0 x 393.0 x 475.0mm ( 16-5/16 x 15-7/16 x 18-11/16inch) .
Polk Monitor XT12 is clearly the larger of the two speakers. Its body is 15mm wider, 3mm taller and 10mm deeper than JBL Stage A120P.
Below you can see the front view size comparison of Polk Monitor XT12 and JBL Stage A120P in scale.
Comparison image of Polk Monitor XT12 and JBL Stage A120P 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 Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2 and base area of the JBL Stage A120P is approximately 1866.8cm2 / 289.4inch2. The Monitor XT12 requires 6% more surface area than the A120P 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 Polk Monitor XT12 weighs 17.73kg / 39lbs and the JBL Stage A120P weighs 18.68kg / 41.1lbs. This makes the A120P 5% heavier than the Monitor XT12.
Here is a comparison of how Monitor XT12 and A120P's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of Polk Monitor XT12?
Here are the items that are included inside the box of Monitor XT12:
Black powered subwoofer6.5-feet AC power cordGrilleOwners ManualOnline registration card
What's in the Box of JBL Stage A120P?
Here are the items that come with the A120P:
Powered subwooferGrille6-feet AC power cord4 Spike feetOwners ManualWarranty CardImportant Safety Instructions
 Low Frequency Response |
24 Hz
vs
32 Hz
|
Generates deeper bass |
 High Frequency Response |
160k Hz
vs
150k Hz
|
Generates higher frequency |
 Height |
415mm
vs
418mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1866cm2
vs
1978cm2
|
Takes less floor space |
 Price per pair* |
300USD
vs
399USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Polk Monitor XT12 |
JBL Stage A120P |
| Brand |
Polk Audio |
JBL |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
50 watts |
250 watts |
| Frequency Response |
24-160 Hz |
32-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
50-watt RMS |
250-watt RMS |
| Watts Peak (Max) |
n/a |
500-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
12" |
| Woofer Composition |
Bi-laminate paper |
Polycellulose |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
418.0mm (16.5") |
415.0mm (16.3") |
| Width |
408.0mm (16.1") |
393.0mm (15.5") |
| Depth |
485.0mm (19.1") |
475.0mm (18.7") |
| Weight |
17.73kg (39lbs) |
18.68kg (41.1lbs) |
| Enclosure |
Bass Reflex |
Bass reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
1 Year |
| Labor Warranty |
3 Years |
1 Year |