In this review, we will be comparing Monitor XT12 and A100P, 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 A100P 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 Polk Monitor XT12and JBL Stage A100P have a single woofer setup however the Polk Monitor XT12's woofer is 12-inch whereas the JBL Stage A100P features a 10-inch woofer.
Frequency Response
Monitor XT12 has a frequency range of 24-160 Hz whereas A100P has a frequency range of 35-150 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 A100P's min frequency of 35Hz.
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 A100P have Bass reflex type enclosure.
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 Polk Monitor XT12's and JBL Stage A100P'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 A100P has external dimensions of 359.0 x 337.0 x 435.0mm (14-1/8 x 13-1/4 x 17-1/8inch).
Polk Monitor XT12 is clearly the larger of the two speakers. Its body is 71mm wider, 59mm taller and 50mm deeper than JBL Stage A100P.
Below you can see the front view size comparison of Polk Monitor XT12 and JBL Stage A100P in scale.
Comparison image of Polk Monitor XT12 and JBL Stage A100P 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 A100P is approximately 1466.0cm2 / 227.2inch2. The Monitor XT12 requires 35% more surface area than the A100P 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 A100P weighs 13.66kg / 30.1lbs. This makes the Monitor XT12 30% heavier than the A100P.
Here is a comparison of how Monitor XT12 and A100P'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 subwoofer
- 6.5-feet AC power cord
- Grille
- Owners Manual
- Online registration card
What's in the Box of JBL Stage A100P?
Here are the items that come with the A100P:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- 4 Spike feet
- Owners Manual
- Warranty Card
- Important Safety Instructions
 Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
35 Hz
|
Generates deeper bass |
 High Frequency Response |
160 Hz
vs
150 Hz
|
Generates higher frequency |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Height |
359mm
vs
418mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1466cm2
vs
1978cm2
|
Takes less floor space |
 Price per pair* |
240USD
vs
399USD
|
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 35% more floor area. Polk Monitor XT12 stands 50mm further into the room. Polk Monitor XT12 is 59mm taller.
| General |
Polk Monitor XT12 |
JBL Stage A100P |
| Brand |
Polk Audio |
JBL |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
50 watts |
150 watts |
| Frequency Response |
24-160 Hz |
35-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
50-watt RMS |
150-watt RMS |
| Watts Peak (Max) |
n/a |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
10" |
| Woofer Composition |
Bi-laminate paper |
Polycellulose |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
rear |
Physical Specs |
|
|
| Height |
418.0mm (16.5") |
359.0mm (14.1") |
| Width |
408.0mm (16.1") |
337.0mm (13.3") |
| Depth |
485.0mm (19.1") |
435.0mm (17.1") |
| Weight |
17.73kg (39lbs) |
13.66kg (30.1lbs) |
| 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 |
Different price classes - Polk Monitor XT12 costs roughly 1.7x what JBL Stage A100P does. Before paying it, read the note below about two smaller subwoofers.
| Area | Better | Why |
|---|
| Bass depth | A | Polk Monitor XT12 goes deeper - 24Hz against 35Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | B | JBL Stage A100P has the bigger amplifier - 150W against 50W RMS, about 4.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Polk Monitor XT12 moves more air: 12" against 10" is 1.44x the cone area, not the 1.2x 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. |
| Speaker-level inputs | A | Polk Monitor XT12 takes a speaker-level connection as well as line level. That is what lets it work with an integrated amplifier or a vintage receiver that has no subwoofer output at all. |
| Cabinet size | depends | JBL Stage A100P is about 36% 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. |
| Warranty | A | Polk Monitor XT12 carries 3 years on parts against 1 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | B | JBL Stage A100P costs less - $240 against $399, about 40% less. |
A Polk Monitor XT12 B JBL Stage A100P
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: Polk Monitor XT12 measures better, JBL Stage A100P costs about 40% less. In a normal room, placement will make a bigger difference than the gap between these two. Check your amplifier first: if it has no subwoofer or preamp output, Polk Monitor XT12 is the only one of these two you can connect at all. 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 $240 each, two JBL Stage A100P cost about $480 against $399 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.