In this review, we will be comparing D320 and S15, two Passive Bookshelf speakers from Wharfedale and Polk Audio.
Let's have a brief look at the main features
of Wharfedale D320 and Polk S15 first before getting into our more
detailed comparison.
| Key Specs | Wharfedale D320 | Polk S15 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Dome |
|---|
| Woofer | 5" Woven Kevlar | 5.25" Mica-reinforced polypropylene |
|---|
| Frequency response | 56-20k Hz | 50-40k Hz |
|---|
| Sensitivity | 87 dB | 88 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 25-100 watts | 20-100 watts |
|---|
| Weight | 6.02kg / 13.2lbs | 5.90kg / 13lbs |
|---|
| Dimensions (H x W x D) | 12-5/8" x 7-1/8" x 10-7/8"
321.0 x 181.0 x 277.0mm | 12.0" x 7.4" x 10.2"
304.8 x 190.0 x 260.4mm |
|---|
What size room are the Wharfedale D320 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:
| Listening Environment* |
Wharfedale D320 |
Polk S15 |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
Bad |
(* 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 D320 and S15 are 2-way speakers.
Wharfedale D320Polk S15
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Wharfedale D320 |
Polk S15 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
1 x 5.25-inch
|
D320 features a 1" Soft-Dome Tweeter and 1 x 5" Woven Kevlar Woofer. 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
D320 has a frequency range of 56-20k Hz whereas S15 has a frequency range of 50-40k Hz. With a minimum frequency of 50Hz, the S15 can go significantly deeper on the low side and provide stronger bass compared to the D320's min frequency of 56Hz.
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
D320 and S15 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. D320 sensitivity is rated at 87 dB and the S15's is at 88 dB. This 1 dB difference makes the Polk S15 a more sensitive speaker compared to Wharfedale D320, 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.
Both handle the same maximum of 100 watts RMS, though D320 is rated 25-100 watts and S15 20-100 watts.
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
D320 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.
Wharfedale D320's Post terminals
Cabinet Type and Port Position
D320 has a bottom firing port whereas S15 has a rear firing ports. Wharfedale D320's bottom-firing port gives more flexibility in placement in regards to proximity to walls compared to Polk S15 with its rear-firing port.
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 Wharfedale D320's and Polk S15's external dimensions. Wharfedale D320 has external dimensions of 321.0 x 181.0 x 277.0mm (12-5/8 x 7-1/8 x 10-7/8inch) whereas Polk S15 has external dimensions of 304.8 x 190.0 x 260.4mm (12.0 x 7.4 x 10.2inch).
Polk S15 is 16.2mm shorter and 16.6mm less deeper than Wharfedale D320 but it is also 9mm wider.
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 Wharfedale D320 is approximately 501.4cm2 / 77.7inch2 and base area of the Polk S15 is approximately 494.8cm2 / 76.7inch2. The D320 requires 1% more surface area than the S15 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 Wharfedale D320 weighs 6.02kg / 13.2lbs and the Polk S15 weighs 5.90kg / 13lbs. This makes the D320 2% heavier than the S15.
Here is a comparison of how D320 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 Wharfedale D320?
Here are the items that are included inside the box of D320:
- 2 Bookshelf loudspeakers
- 2 Tweeter grilles (pre-installed)
- 2 Woofer grilles (pre-installed)
- User-feets Manual
- Installation Guide
What's in the Box of Polk S15?
Here are the items that come with the S15:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Wall-mount template
- Owners Manual
- Online Product Registration
 Price per pair* |
249USD
vs
259USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
88 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
|
Low Frequency Response |
50 Hz
vs
56 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
20k Hz
|
Generates higher frequency |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Height |
304mm
vs
321mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
494cm2
vs
501cm2
|
Takes less floor space |
| General |
Wharfedale D320 |
Polk Audio Signature S15 |
| Brand |
Wharfedale |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-100 watts |
20-100 watts |
| Sensitivity |
87 dB |
88 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
3.8 ohms |
n/a |
| Frequency Response |
56-20k Hz |
50-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5" |
5.25" |
| Woofer Composition |
Woven Kevlar |
Mica-reinforced polypropylene |
| Woofer Surround Material |
Foamed Polyether |
Butyl rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
bottom |
rear |
Physical Specs |
|
|
| Height |
321.0mm (12.6") |
304.8mm (12") |
| Width |
181.0mm (7.1") |
190.0mm (7.5") |
| Depth |
277.0mm (10.9") |
260.4mm (10.3") |
| Weight |
6.02kg (13.2lbs) |
5.90kg (13lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
Meddite MDF |
| Available Colors |
Rosewood, Black, White, Walnut |
Black, Walnut, Brown Walnut |
| Mounting Bracket |
No |
Keyhole |
| Recommended Stand Height |
22-24" |
24-30" |
| 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 |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass |
B |
Polk S15 digs deeper - 50Hz against 56Hz. A subwoofer would even that out. |
| Amplifier needs |
evenly matched |
Similar sensitivity (87dB vs 88dB) - both want much the same power. |
| Headroom |
evenly matched |
Similar power handling (100W vs 100W). |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Price |
evenly matched |
Much the same money ($249 vs $259 a pair). |
A Wharfedale D320
B Polk S15
depends neither is better in the abstract - it turns on your room, placement 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 S15 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 56Hz anyway, so judge these on the other rows instead.
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.