In this review, we will be comparing ES20 and Sib-T, two Passive Bookshelf speakers from Polk Audio and Focal.
Let's have a brief look at the main features
of Polk ES20 and Focal Sib-T first before getting into our more
detailed comparison.
| Key Specs | Polk ES20 | Focal Sib-T |
|---|
| Brand | Polk Audio
United States · founded 1972 | Focal
France · founded 1979 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | .75" Dome |
|---|
| Woofer | 6.5" Mica-reinforced polypropylene | 5.125" Polyflex |
|---|
| Frequency response | 41-40k Hz | 80-20kHz |
|---|
| Sensitivity | 86 dB | 90 dB |
|---|
| Impedance | 8 ohms | 4 ohms |
|---|
| Power range | 20-125 watts | — |
|---|
| Weight | 7.73kg / 17lbs | 2.60kg / 5.7lbs |
|---|
| Dimensions (H x W x D) | 14-3/4" x 8-9/16" x 13-13/16"
375.0 x 218.0 x 351.0mm | 2-1/2" x 5-5/8" x 6-11/16"
64.0 x 143.0 x 170.0mm |
|---|
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 ES20 and Sib-T are 2-way speakers.
Polk ES20Focal Sib-T
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 ES20 |
Focal Sib-T |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
.75-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.125-inch
|
ES20 features a 1" Terylene Soft-Dome Tweeter and 1 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz. On the other hand, the Sib-T features a .75" Dome Tweeter and 1 x 5.125" Polyflex Woofer.
Frequency Response
ES20 has a frequency range of 41-40k Hz whereas Sib-T has a frequency range of 80-20kHz. With a minimum frequency of 41Hz, the ES20 can go significantly deeper on the low side and provide stronger bass compared to the Sib-T's min frequency of 80Hz.
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
ES20 is a 8 ohms speaker compared to the Sib-T which has a nominal impedance of 4 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the Sib-T can provide this impedance level.
These two speakers also have different sensitivity levels. ES20 sensitivity is rated at 86 dB and the Sib-T's is rated at 90 dB. This 4 dB difference makes the Focal Sib-T a more sensitive speaker compared to Polk ES20, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf Speakers
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
ES20 features Spring posts type posts and Sib-T has a Spring posts type posts. None of these speakers feature bi-amping/bi-wiring.
Focal Sib-T's Spring posts terminals
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 ES20's and Focal Sib-T's external dimensions. Polk ES20 has external dimensions of 375.0 x 218.0 x 351.0mm (14-3/4 x 8-9/16 x 13-13/16inch) whereas Focal Sib-T has external dimensions of 64.0 x 143.0 x 170.0mm (2-1/2 x 5-5/8 x 6-11/16inch).
Polk ES20 is clearly the larger of the two speakers. Its body is 75mm wider, 311mm taller and 181mm deeper than Focal Sib-T.
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 ES20 is approximately 765.2cm2 / 118.6inch2 and base area of the Focal Sib-T is approximately 243.1cm2 / 37.7inch2. The ES20 requires 215% more surface area than the Sib-T which gives it a small disadvantage on placement in tight spaces.
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 ES20 weighs 7.73kg / 17lbs and the Focal Sib-T weighs 2.60kg / 5.7lbs. This makes the ES20 197% heavier than the Sib-T.
Here is a comparison of how ES20 and Sib-T'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 ES20?
Here are the items that are included inside the box of ES20:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
What's in the Box of Focal Sib-T?
Here are the items that come with the Sib-T:
- One 100V/4-ohm commercial speaker
- Adjustable mounting bracket (installed)
- 3 Drywall anchors w/ 2 screws
- 5mm Allen key (attached to mounting bracket)
- User manual
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Woofer Size |
6.5 inches
vs
5.125 inches
|
Larger woofer |
|
Low Frequency Response |
41 Hz
vs
80 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
20k Hz
|
Generates higher frequency |
 Price per pair* |
399USD
vs
698USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
90 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Height |
64mm
vs
375mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
243cm2
vs
765cm2
|
Takes less floor space |
| General |
Polk Audio Signature Elite ES20 |
Focal Sib-T |
| Brand |
Polk Audio |
Focal |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Sensitivity |
86 dB |
90 dB |
| Impedance |
8 ohms |
4 ohms |
| Frequency Response |
41-40k Hz |
80-20kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
5.125" |
| Woofer Composition |
Mica-reinforced polypropylene |
Polyflex |
| Woofer Surround Material |
Butyl rubber |
n/a |
| Tweeter Size |
1" |
.75" |
| Tweeter Type |
Soft-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
n/a |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
375.0mm (14.8") |
64.0mm (2.5") |
| Width |
218.0mm (8.6") |
143.0mm (5.6") |
| Depth |
351.0mm (13.8") |
170.0mm (6.7") |
| Weight |
7.73kg (17lbs) |
2.60kg (5.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Wood-grain vinyl |
Plastic |
| Available Colors |
Black,White,Walnut |
White |
| Mounting Bracket |
No |
Yes |
| Recommended Stand Height |
22-26" |
2-1/2" |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - Focal Sib-T costs roughly 1.7x what Polk ES20 does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | A | Polk ES20 digs deeper - 41Hz against 80Hz. |
| Amplifier needs | B | Focal Sib-T is more sensitive (90dB vs 86dB), so it goes louder on the same amplifier. |
| Amplifier match | A | Polk ES20 is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Size | depends | Focal Sib-T is easier to place; Polk ES20 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Polk ES20 sits in a wider range (12 models), so a matched surround system is easier later. |
| Price | A | Polk ES20 is cheaper - $399 against $698, about 43% less; arguably a different class. |
A Polk ES20 B Focal Sib-T
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?
Polk ES20 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 80Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Polk ES20 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Focal Sib-T 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.