In this review, we will be comparing Flexus Sub 100 and Monitor XT12, two Powered Subwoofer speakers from Klipsch 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 Klipsch Flexus Sub 100 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.Both Klipsch Flexus Sub 100and Polk Monitor XT12 have a single woofer setup however the Klipsch Flexus Sub 100's woofer is 10-inch whereas the Polk Monitor XT12 features a 12-inch woofer.
Frequency Response
Flexus Sub 100 has a frequency range of 26-250 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 Flexus Sub 100's min frequency of 26Hz.
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 Klipsch Flexus Sub 100 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
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 Klipsch Flexus Sub 100's and Polk Monitor XT12's external dimensions. Klipsch Flexus Sub 100 has external dimensions of 340.0 x 335.0 x 349.0mm (13-3/8 x 13-3/16 x 13-3/4inch) 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 73mm wider, 78mm taller and 136mm deeper than Klipsch Flexus Sub 100.
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.
Polk Monitor XT12 needs about 69% more floor or shelf area. Polk Monitor XT12 is 136mm deeper, so it stands that much further out from the wall. Polk Monitor XT12 is 78mm 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 Klipsch Flexus Sub 100 is approximately 1169.2cm2 / 181.2inch2 and base area of the Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2. The Flexus Sub 100 requires 41% 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 Klipsch Flexus Sub 100 weighs 9.40kg / 20.7lbs and the Polk Monitor XT12 weighs 17.73kg / 39lbs. This makes the Monitor XT12 89% heavier than the Flexus Sub 100.
Here is a comparison of how Flexus Sub 100 and Monitor XT12's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 High Frequency Response |
250 Hz
vs
160 Hz
|
Generates higher frequency |
 Height |
340mm
vs
418mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1169cm2
vs
1978cm2
|
Takes less floor space |
 Price per pair* |
350USD
vs
399USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Yes
vs
No
|
Connect your subwoofer to your system wireless |
 Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
26 Hz
|
Generates deeper bass |
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 69% more floor area. Polk Monitor XT12 stands 136mm further into the room. Polk Monitor XT12 is 78mm taller.
| General |
Klipsch Flexus Sub 100 |
Polk Monitor XT12 |
| Brand |
Klipsch |
Polk Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
80 watts |
50 watts |
| Frequency Response |
26-250 Hz |
24-160 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
80-watt RMS |
50-watt RMS |
| Watts Peak (Max) |
160-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
12" |
| Woofer Composition |
Paper |
Bi-laminate paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
340.0mm (13.4") |
418.0mm (16.5") |
| Width |
335.0mm (13.2") |
408.0mm (16.1") |
| Depth |
349.0mm (13.7") |
485.0mm (19.1") |
| Weight |
9.40kg (20.7lbs) |
17.73kg (39lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
3 Years |
| Labor Warranty |
5 Years |
3 Years |
A sealed subwoofer against a ported one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | evenly matched | Effectively the same reach (26Hz vs 24Hz). |
| Amplifier power | A | Klipsch Flexus Sub 100 has the bigger amplifier - 80W against 50W RMS, about 2dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | 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 | depends | Klipsch Flexus Sub 100 is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; Polk Monitor XT12 is ported - a ported box gives more output low down for its size, at the cost of a steeper roll-off below tuning. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Wireless option | depends | Only Klipsch Flexus Sub 100 offers a wireless link. It decides where the sub can go if you cannot run a cable, and is worth nothing if you can. |
| Cabinet size | depends | Klipsch Flexus Sub 100 is about 52% 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 | Klipsch Flexus Sub 100 carries 5 years on parts against 3 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | A | Klipsch Flexus Sub 100 costs less - $350 against $399, about 12% less. |
A Klipsch Flexus Sub 100 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?
Klipsch Flexus Sub 100 has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is. Films or music? If this is mainly a home cinema, Polk Monitor XT12 will hit harder for the money; if it is mainly for music in a normal-sized room, Klipsch Flexus Sub 100 is usually the easier one to make sound right. If placement is the constraint - a corner, behind a sofa, under a desk - Klipsch Flexus Sub 100 is the one that will actually go there, and a well-placed small subwoofer beats a badly-placed big one every time.
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.