In this review, we will be comparing Kube 15 MIE and Monitor XT12, two Powered Subwoofer speakers from KEF 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 KEF Kube 15 MIE and Polk Monitor XT12 first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the KEF Kube 15 MIE and Polk Monitor XT12 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 KEF Kube 15 MIEand Polk Monitor XT12 have a single woofer setup however the KEF Kube 15 MIE's woofer is 15-inch whereas the Polk Monitor XT12 features a 12-inch woofer.
Frequency Response
Kube 15 MIE has a frequency range of 20-140 Hz whereas Monitor XT12 has a frequency range of 24-160 Hz. With a minimum frequency of 20Hz, the Kube 15 MIE can go slightly deeper then 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
The KEF Kube 15 MIE 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
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 KEF Kube 15 MIE's and Polk Monitor XT12's external dimensions. KEF Kube 15 MIE has external dimensions of 519 x 500 x 515 mm ( 20.4 x 19.7 x 20.3 in) 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 ) .
KEF Kube 15 MIE is clearly the larger of the two speakers. Its body is 92mm wider, 101mm taller and 30mm deeper than Polk Monitor XT12.
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 KEF Kube 15 MIE is approximately 2575.0cm2 / 399.1inch2 and base area of the Polk Monitor XT12 is approximately 1978.8cm2 / 306.7inch2. The Kube 15 MIE requires 30% more surface area than the Monitor XT12 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 KEF Kube 15 MIE weighs 27.50kg / 60.5lbs and the Polk Monitor XT12 weighs 17.73kg / 39lbs. This makes the Kube 15 MIE 55% heavier than the Monitor XT12.
Here is a comparison of how Kube 15 MIE and Monitor XT12's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of KEF Kube 15 MIE?
Here are the items that are included inside the box of Kube 15 MIE:
Kube 15 MIE subwoofer Power cord Euroblock speaker level connector User manual and warranty information
What's in the Box of Polk Monitor XT12?
Here are the items that come with the Monitor XT12:
Black powered subwoofer6.5-feet AC power cordGrilleOwners ManualOnline registration card
 Woofer Size |
15 inches
vs
12 inches
|
Larger woofer |
| Low Frequency Response |
20 Hz
vs
24 Hz
|
Generates deeper bass |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
 High Frequency Response |
160k Hz
vs
140k Hz
|
Generates higher frequency |
 Height |
418mm
vs
519mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1978cm2 (408x485mm)
vs
2575cm2 (500x515mm)
|
Takes less floor space |
 Price per pair* |
399USD
vs
1399USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF Kube 15 MIE |
Polk Monitor XT12 |
| Brand |
KEF |
Polk Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
50 watts |
| Frequency Response |
20-140 Hz |
24-160 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
50-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
15" |
12" |
| Woofer Composition |
Polypropylene |
Bi-laminate paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
519.0mm (20.4") |
418.0mm (16.5") |
| Width |
500.0mm (19.7") |
408.0mm (16.1") |
| Depth |
515.0mm (20.3") |
485.0mm (19.1") |
| Weight |
27.50kg (60.5lbs) |
17.73kg (39lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 Years |