In this review, we will be comparing Monitor XT12 and SPL-150, two Powered Subwoofer speakers from Polk Audio and Klipsch. 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 Klipsch SPL-150 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 Klipsch SPL-150 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 Polk Monitor XT12and Klipsch SPL-150 have a single woofer setup however the Polk Monitor XT12's woofer is 12-inch whereas the Klipsch SPL-150 features a 15-inch woofer.
Frequency Response
Monitor XT12 has a frequency range of 24-160 Hz whereas SPL-150 has a frequency range of 18-125 Hz. With a minimum frequency of 18Hz, the SPL-150 can go significantly deeper on the low side and provide stronger bass compared to the Monitor XT12's min frequency of 24Hz.
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 Polk Monitor XT12 and Klipsch SPL-150 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
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 Klipsch SPL-150'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 Klipsch SPL-150 has external dimensions of 547.0 x 496.0 x 604.0mm ( 21-1/2 x 19-1/2 x 23-3/4inch) .
Klipsch SPL-150 is clearly the larger of the two speakers. Its body is 88mm wider, 129mm taller and 119mm deeper than Polk Monitor XT12.
Below you can see the front view size comparison of Polk Monitor XT12 and Klipsch SPL-150 in scale.
Comparison image of Polk Monitor XT12 and Klipsch SPL-150 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 Klipsch SPL-150 is approximately 2995.8cm2 / 464.3inch2. The Monitor XT12 requires 34% less surface area than the SPL-150 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 Polk Monitor XT12 weighs 17.73kg / 39lbs and the Klipsch SPL-150 weighs 34.27kg / 75.4lbs. This makes the SPL-150 93% heavier than the Monitor XT12.
Here is a comparison of how Monitor XT12 and SPL-150'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 Klipsch SPL-150?
Here are the items that come with the SPL-150:
Powered subGrille6.5-feet AC power cordUser ManualImportant Safety InstructionsWarranty Information
 High Frequency Response |
160k Hz
vs
125k Hz
|
Generates higher frequency |
 Height |
418mm
vs
547mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1978cm2 (408x485mm)
vs
2995cm2 (496x604mm)
|
Takes less floor space |
 Price per pair* |
399USD
vs
1399USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
15 inches
vs
12 inches
|
Larger woofer |
| Low Frequency Response |
18 Hz
vs
24 Hz
|
Generates deeper bass |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
| General |
Polk Monitor XT12 |
Klipsch SPL-150 |
| Brand |
Polk Audio |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
50 watts |
400 watts |
| Frequency Response |
24-160 Hz |
18-125 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
50-watt RMS |
400-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
15" |
| Woofer Composition |
Bi-laminate paper |
Cerametallic |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
418.0mm (16.5") |
547.0mm (21.5") |
| Width |
408.0mm (16.1") |
496.0mm (19.5") |
| Depth |
485.0mm (19.1") |
604.0mm (23.8") |
| Weight |
17.73kg (39lbs) |
34.27kg (75.4lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
2 Years |
| Labor Warranty |
3 Years |
2 Years |