In this review, we will be comparing QX-12SUB MKII and Monitor XT12, two Powered Subwoofer speakers from Mission 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 Mission QX-12SUB MKII 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.Mission QX-12SUB MKIIand Polk Monitor XT12 have the same driver set up: Both subwoofers have 1 x 12" drivers.
Frequency Response
QX-12SUB MKII has a frequency range of 35-120 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 QX-12SUB MKII'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
Both Mission QX-12SUB MKII 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 Mission QX-12SUB MKII's and Polk Monitor XT12's external dimensions. Mission QX-12SUB MKII has external dimensions of 478.0 x 400.0 x 465.0mm (18-13/16 x 15-3/4 x 18-5/16inch) 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).
Mission QX-12SUB MKII is 8mm narrower and 20mm less deeper than Polk Monitor XT12 but it is also 60mm taller.
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.
Near-identical footprints. Polk Monitor XT12 is 20mm deeper, so it stands that much further out from the wall. Mission QX-12SUB MKII is 60mm 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 Mission QX-12SUB MKII is approximately 1860.0cm2 / 288.3inch2 and base area of the Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2. The QX-12SUB MKII requires 6% 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 Mission QX-12SUB MKII weighs 23.00kg / 50.6lbs and the Polk Monitor XT12 weighs 17.73kg / 39lbs. This makes the QX-12SUB MKII 30% heavier than the Monitor XT12.
Here is a comparison of how QX-12SUB MKII and Monitor XT12's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Base Surface Area |
1860cm2
vs
1978cm2
|
Takes less floor space |
 Low Frequency Response |
24 Hz
vs
35 Hz
|
Generates deeper bass |
 High Frequency Response |
160 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
418mm
vs
478mm
|
Easier to fit in smaller spaces |
 Price per pair* |
399USD
vs
699USD
|
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.
Near-identical footprints. Polk Monitor XT12 stands 20mm further into the room. Mission QX-12SUB MKII is 60mm taller.
| General |
Mission QX-12SUB MKII |
Polk Monitor XT12 |
| Brand |
Mission |
Polk Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
50 watts |
| Frequency Response |
35-120 Hz |
24-160 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
50-watt RMS |
| Watts Peak (Max) |
450-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
12" |
| Woofer Composition |
Paper |
Bi-laminate paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
30 - 150 Hz |
n/a |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
478.0mm (18.8") |
418.0mm (16.5") |
| Width |
400.0mm (15.7") |
408.0mm (16.1") |
| Depth |
465.0mm (18.3") |
485.0mm (19.1") |
| Weight |
23.00kg (50.6lbs) |
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 |
Different price classes - Mission QX-12SUB MKII costs roughly 1.8x what Polk Monitor XT12 does. Before paying it, read the note below about two smaller subwoofers.
| Area | Better | Why |
|---|
| Bass depth | B | 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 | A | Mission QX-12SUB MKII has the bigger amplifier - 300W against 50W RMS, about 7.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | evenly matched | Near-identical radiating area (12" against 12"). |
| Enclosure | evenly matched | Both are ported designs, so they roll off in much the same way. |
| Price | B | Polk Monitor XT12 costs less - $399 against $699, about 43% less. |
A Mission QX-12SUB MKII 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?
Neither runs away with it - they trade advantages. Let your room size and where the box can actually stand settle it. 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 $699 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.