In this review, we will be comparing 3020i and S15, two Passive Bookshelf speakers from Q Acoustics and Polk Audio. Let's have a brief look at the main features
of Q Acoustics 3020i and Polk S15 first before getting into our more
detailed comparison.
What size room are the Q Acoustics 3020i and Polk S15 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:
In the following sections, we will get into more detail in order to better understand how the Q Acoustics 3020i and Polk S15 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
Both 3020i and S15 are 2-way speakers.
| Driver |
Q Acoustics 3020i |
Polk S15 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.9-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
1 x 5.25-inch
|
3020i features a 0.9" decoupled Tweeter and 1 x 5" Coated paper Woofer with a Crossover frequency at 2400Hz and 2400Hz. On the other hand, the S15 features a 1" Terylene Dome Tweeter and 1 x 5.25" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz.
Frequency Response
3020i has a frequency range of 64-30k Hz whereas S15 has a frequency range of 50-40k Hz. With a minimum frequency of 46Hz, the 3020i can go slightly deeper then the S15's min frequency of 50Hz.
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 Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
High Frequency
Bookshelf Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
3020i is a 6 ohms speaker compared to the S15 which has a nominal impedance of 8 ohms.
On the other hand, they have the same sensitivity of 88 dBdB.
Sensitivity
Bookshelf Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
3020i can handle a max power of 100 watts RMS from the amp the whereas 3020i has a max power handling value of 75 watts RMS , 25 watts less than the S15.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
3020i features Pair of Binding Posts - Gold Plated type posts and S15 has a Pair of Binding Posts - Gold Plated type posts. None of these speakers feature bi-amping/bi-wiring.
Cabinet Type and Port Position
Both 3020i and S15 have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
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 Q Acoustics 3020i's and Polk S15's external dimensions. Q Acoustics 3020i has external dimensions of 278.0 x 170.0 x 282.0mm ( 10.9 x 6.6 x 11.1inch) whereas Polk S15 has external dimensions of 304.8 x 190.0 x 260.4mm ( 12.0 x 7.4 x 10.2inch) .
Q Acoustics 3020i is 20mm narrower and 26.8mm shorter than Polk S15 but it is also 21.6mm deeper.
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 Q Acoustics 3020i is approximately 479.4cm2 / 74.3inch2 and base area of the Polk S15 is approximately 494.8cm2 / 76.7inch2. The 3020i requires 3% less surface area than the S15 which gives it a small advantage 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 Q Acoustics 3020i weighs 4.80kg / 10.6lbs and the Polk S15 weighs 5.90kg / 13lbs. This makes the S15 23% heavier than the 3020i.
Here is a comparison of how 3020i and S15's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Q Acoustics 3020i?
Here are the items that are included inside the box of 3020i:
2 x 3020i bookshelf speakers 2 x Foam Bungs 2 x Speaker Grilles 1 x User Manual 1 x Handling Gloves 8 x Rubber Speaker Grips
What's in the Box of Polk S15?
Here are the items that come with the S15:
2 Bookshelf loudspeakers2 Grille (attached)8 Self-adhesive rubber feetWall-mount templateOwners ManualOnline Product Registration
 Low Frequency Response |
46 Hz
vs
50 Hz
|
Generates deeper bass |
 Height |
278mm
vs
304mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
479cm2 (170x282mm)
vs
494cm2 (190x260mm)
|
Takes less floor space |
 Max Input Power |
100 watts
vs
75 watts
|
Handle more power from your amplifier |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
| Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
 High Frequency Response |
40k Hz
vs
30k Hz
|
Generates higher frequency |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Price per pair* |
259USD
vs
399USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Q Acoustics 3020i |
Polk Audio Signature S15 |
| Brand |
Q Acoustics |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-75 watts |
20-100 watts |
| Sensitivity |
88 dB |
88 dB |
| Impedance |
6 ohms |
8 ohms |
| Impedance |
4 ohms |
n/a |
| Frequency Response |
64-30k Hz |
50-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5" |
5.25" |
| Woofer Composition |
Coated paper |
Mica-reinforced polypropylene |
| Woofer Surround Material |
Rubber |
Butyl rubber |
| Tweeter Size |
0.9" |
1" |
| Tweeter Type |
decoupled |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2400Hz and 2400Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
278.0mm (10.9") |
304.8mm (12") |
| Width |
170.0mm (6.7") |
190.0mm (7.5") |
| Depth |
282.0mm (11.1") |
260.4mm (10.3") |
| Weight |
4.80kg (10.6lbs) |
5.90kg (13lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
Meddite MDF |
| Available Colors |
Walnut, Black, White, Grey |
Black, Walnut, Brown Walnut |
| Mounting Bracket |
No |
Keyhole |
| Recommended Stand Height |
n/a |
24-30" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
4 Years |
5 Years |
| Labor Warranty |
4 Years |
5 Years |