In this review, we will be comparing XT15 and XT20, two Passive Bookshelf speakers by Polk Audio.
Let's have a brief look at the main features
of Polk XT15 and Polk XT20 first before getting into our more
detailed comparison.
| Key Specs | Polk XT15 | Polk XT20 |
|---|
| Brand | Polk Audio
United States · founded 1972 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Soft-Dome |
|---|
| Woofer | 5.25" Bi-laminate paper | 6.5" Bi-laminate paper |
|---|
| Frequency response | 48-40k Hz | 38-40k Hz |
|---|
| Sensitivity | 86 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 30-150 watts | 30-200 watts |
|---|
| Weight | 4.09kg / 9lbs | 5.45kg / 12lbs |
|---|
| Dimensions (H x W x D) | 10-5/8" x 6-9/16" x 7-3/16"
270.0 x 167.0 x 183.0mm | 13-1/16" x 7-9/16" x 11-1/16"
332.0 x 193.0 x 281.0mm |
|---|
XT15 and XT20 are members of Polk Audio's Monitor XT series of speakers. Below you can find the loudspeakers from this series.
What size room are the Polk XT15 and Polk XT20 speakers good for?
The size of the room in which you are planning to use these loudspeakers is an important decision
factor. Here we have compared their suitability to various sizes of environments considering their size
and max power parameters:
| Listening Environment* |
Polk XT15 |
Polk XT20 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
Poor |
(* Approximate Room sizes: Small < 100sq. ft / 9 m2,
Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: >
400 sq. ft / 36 m2.
Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual
listening experience changes depending on floor height, room shape, surface materials, listening
position, speaker locations, etc.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
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Drivers
Both XT15 and XT20 are 2-way speakers.
Polk XT15Polk XT20
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Polk XT15 |
Polk XT20 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 6.5-inch
|
XT15 features a 1" Soft-Dome Tweeter and 1 x 5.25" Bi-laminate paper Woofer. On the other hand, the XT20 features a 1" Soft-Dome Tweeter and 1 x 6.5" Bi-laminate paper Woofer.
Frequency Response
XT15 has a frequency range of 48-40k Hz whereas XT20 has a frequency range of 38-40k Hz. With a minimum frequency of 38Hz, the XT20 can go significantly deeper on the low side and provide stronger bass compared to the XT15's min frequency of 48Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
XT15 and XT20 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. XT15 sensitivity is rated at 86 dB and the XT20's is at 87 dB. This 1 dB difference makes the Polk XT20 a more sensitive speaker compared to Polk XT15, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
XT20 can handle a max power of 200 watts RMS, whereas XT15 has a max power handling value of 150 watts RMS, 50 watts less than the XT20.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
Input Type and Bi-Amping / Bi-Wiring
XT15 features 5-Way post type posts and XT20 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
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 XT15's and Polk XT20's external dimensions. Polk XT15 has external dimensions of 270.0 x 167.0 x 183.0mm (10-5/8 x 6-9/16 x 7-3/16inch) whereas Polk XT20 has external dimensions of 332.0 x 193.0 x 281.0mm (13-1/16 x 7-9/16 x 11-1/16inch).
Polk XT20 is clearly the larger of the two speakers. Its body is 26mm wider, 62mm taller and 98mm deeper than Polk XT15.
Below you can see the front view size comparison of Polk XT15 and Polk XT20 in scale.
Comparison image of Polk XT15 and Polk XT20 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 XT15 is approximately 305.6cm2 / 47.4inch2 and base area of the Polk XT20 is approximately 542.3cm2 / 84.1inch2. The XT15 requires 44% less surface area than the XT20 which gives it a small advantage on placement in tight spaces.
Here is another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
Size Comparison image of Polk XT15 and Polk XT20 on a Media Console
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The Polk XT15 weighs 4.09kg / 9lbs and the Polk XT20 weighs 5.45kg / 12lbs. This makes the XT20 33% heavier than the XT15.
Here is a comparison of how XT15 and XT20's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Polk XT15?
Here are the items that are included inside the box of XT15:
- 2 Bookshelf loudspeakers
- 2 Grilles (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
What's in the Box of Polk XT20?
Here are the items that come with the XT20:
- 2 Bookshelf loudspeakers
- 2 Grilles (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
 Height |
270mm
vs
332mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
305cm2
vs
542cm2
|
Takes less floor space |
 Price per pair* |
199USD
vs
299USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
200 watts
vs
150 watts
|
Handle more power from your amplifier |
 Sensitivity |
87 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
38 Hz
vs
48 Hz
|
Generates deeper bass |
| General |
Polk Audio Monitor XT15 |
Polk Audio Monitor XT20 |
| Brand |
Polk Audio |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-150 watts |
30-200 watts |
| Sensitivity |
86 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
48-40k Hz |
38-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
Bi-laminate paper |
Bi-laminate paper |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
Physical Specs |
|
|
| Height |
270.0mm (10.6") |
332.0mm (13.1") |
| Width |
167.0mm (6.6") |
193.0mm (7.6") |
| Depth |
183.0mm (7.2") |
281.0mm (11.1") |
| Weight |
4.09kg (9lbs) |
5.45kg (12lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Vinyl |
MDF, Vinyl |
| Available Colors |
Black |
Black |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
28-32" |
24-28" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
Siblings in Polk Audio's Monitor XT series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | B | Polk XT20 digs deeper - 38Hz against 48Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (86dB vs 87dB) - both want much the same power. |
| Headroom | B | Polk XT20 takes more power (200W vs 150W) - more in hand in a big room. |
| Size | depends | Polk XT15 is easier to place; Polk XT20 is bigger, which usually goes with fuller bass. Your room decides. |
| Price | A | Polk XT15 is cheaper - $199 against $299, about 33% less. |
A Polk XT15 B Polk XT20
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 speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: Polk XT20 measures better, Polk XT15 costs about about 50% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 48Hz anyway, which makes the cheaper Polk XT15 much easier to justify. In a large or open-plan room, Polk XT20 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Polk XT15 is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.