In this review, we will be comparing Monitor XT12 and SB-4000, two Powered Subwoofer speakers from Polk Audio and SVS. 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 SVS SB-4000 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 SVS SB-4000 have a single woofer setup however the Polk Monitor XT12's woofer is 12-inch whereas the SVS SB-4000 features a 13.5-inch woofer.
Frequency Response
Monitor XT12 has a frequency range of 24-160 Hz whereas SB-4000 has a frequency range of 19-310 Hz. With a minimum frequency of 19Hz, the SB-4000 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
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 SVS SB-4000 have Acoustic Suspension type enclosure. 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.
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 SVS SB-4000'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 SVS SB-4000 has external dimensions of 466.0 x 453.0 x 532.0mm (18-5/16 x 17-13/16 x 20-15/16inch).
SVS SB-4000 is clearly the larger of the two speakers. Its body is 45mm wider, 48mm taller and 47mm deeper than Polk Monitor XT12.
Below you can see the front view size comparison of Polk Monitor XT12 and SVS SB-4000 in scale.
Comparison image of Polk Monitor XT12 and SVS SB-4000 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 SVS SB-4000 is approximately 2410.0cm2 / 373.6inch2. The Monitor XT12 requires 18% less surface area than the SB-4000 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 SVS SB-4000 weighs 46.50kg / 102.3lbs. This makes the SB-4000 162% heavier than the Monitor XT12.
Here is a comparison of how Monitor XT12 and SB-4000'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 SVS SB-4000?
Here are the items that come with the SB-4000:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- Remote control
- 4 Elastomer feet
- Owners Manual
- Important Safety Instructions
 Height |
418mm
vs
466mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1978cm2
vs
2410cm2
|
Takes less floor space |
 Price per pair* |
399USD
vs
1800USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
13.5 inches
vs
12 inches
|
Larger woofer |
| Low Frequency Response |
19 Hz
vs
24 Hz
|
Generates deeper bass |
 High Frequency Response |
310 Hz
vs
160 Hz
|
Generates higher frequency |
 App-Based Control |
iOS,Android
vs
None
|
Control the speaker via an app |
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.
SVS SB-4000 needs about 22% more floor area. SVS SB-4000 stands 47mm further into the room. SVS SB-4000 is 48mm taller.
| General |
Polk Monitor XT12 |
SVS SB-4000 |
| Brand |
Polk Audio |
SVS |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
50 watts |
1200 watts |
| Frequency Response |
24-160 Hz |
19-310 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
50-watt RMS |
1200-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
13.5" |
| Woofer Composition |
Bi-laminate paper |
Composite/Glass Fiber |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
418.0mm (16.5") |
466.0mm (18.3") |
| Width |
408.0mm (16.1") |
453.0mm (17.8") |
| Depth |
485.0mm (19.1") |
532.0mm (20.9") |
| Weight |
17.73kg (39lbs) |
46.50kg (102.3lbs) |
| Enclosure |
Bass Reflex |
Acoustic Suspension |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
5 Years |
| Labor Warranty |
3 Years |
5 Years |
A ported subwoofer against a sealed 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 | B | SVS SB-4000 goes deeper - 19Hz against 24Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | B | SVS SB-4000 has the bigger amplifier - 1200W against 50W RMS, about 13.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | SVS SB-4000 moves more air: 13.5" against 12" is 1.27x the cone area, not the 1.13x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | 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; SVS SB-4000 is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| 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 | Polk Monitor XT12 is about 26% 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 | B | SVS SB-4000 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 | Polk Monitor XT12 costs less - $399 against $1,800, about 78% less. |
A Polk Monitor XT12 B SVS SB-4000
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: SVS SB-4000 measures better, Polk Monitor XT12 costs about 78% less. In a normal room, placement will make a bigger difference than the gap between these two. 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, SVS SB-4000 is usually the easier one to make sound right. 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.
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.