In this review, we will be comparing Airmotiv B1+ and ES15, two Passive Bookshelf speakers from Emotiva and Polk Audio.
Let's have a brief look at the main features
of Emotiva Airmotiv B1+ and Polk ES15 first before getting into our more
detailed comparison.
| Key Specs | Emotiva Airmotiv B1+ | Polk ES15 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 25×32 mm" folded ribbon | 1" Soft-Dome |
|---|
| Woofer | 5.25" woven fiber cone | 5.25" Mica-reinforced polypropylene |
|---|
| Frequency response | 48 Hz – 28 kHz | 44-40k Hz |
|---|
| Sensitivity | 86 dB | 85 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | Up to 70 watts | 20-100 watts |
|---|
| Weight | 4.00kg / 8.8lbs | 5.91kg / 13lbs |
|---|
| Dimensions (H x W x D) | 10-3/4" x 7-1/8" x 8-1/4"
274.0 x 181.0 x 210.0mm | 12-1/16" x 7-9/16" x 10-3/16"
307.0 x 193.0 x 259.0mm |
|---|
What size room are the Emotiva Airmotiv B1+ and Polk ES15 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* |
Emotiva Airmotiv B1+ |
Polk ES15 |
| Near-field |
Good |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
No way |
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.
**This post contains affiliate links, and we will be compensated if you make a purchase after clicking
through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Airmotiv B1+ and ES15 are 2-way speakers.
Emotiva Airmotiv B1+Polk ES15
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Emotiva Airmotiv B1+ |
Polk ES15 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
25×32 mm-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5.25-inch
|
Airmotiv B1+ features a 25×32 mm" folded ribbon Tweeter and 1 x 5.25" woven fiber cone Woofer with a Crossover frequency at 2000Hz. On the other hand, the ES15 features a 1" Terylene Soft-Dome Tweeter and 1 x 5.25" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Airmotiv B1+ has a frequency range of 48 Hz – 28 kHz whereas ES15 has a frequency range of 44-40k Hz. With a minimum frequency of 44Hz, the ES15 can go slightly deeper then the Airmotiv B1+'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
Airmotiv B1+ and ES15 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Airmotiv B1+ sensitivity is rated at 86 dB and the ES15's is at 85 dB. This 1 dB difference makes the Emotiva Airmotiv B1+ a more sensitive speaker compared to Polk ES15, 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.
ES15 can handle a max power of 100 watts RMS, whereas Airmotiv B1+ has a max power handling value of 70 watts RMS, 30 watts less than the ES15.
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.
Cabinet Type and Port Position
Both Airmotiv B1+ and ES15 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.
Emotiva Airmotiv B1+ Port
Polk ES15 Power Port 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 Emotiva Airmotiv B1+'s and Polk ES15's external dimensions. Emotiva Airmotiv B1+ has external dimensions of 274.0 x 181.0 x 210.0mm (10-3/4 x 7-1/8 x 8-1/4inch) whereas Polk ES15 has external dimensions of 307.0 x 193.0 x 259.0mm (12-1/16 x 7-9/16 x 10-3/16inch).
Polk ES15 is clearly the larger of the two speakers. Its body is 12mm wider, 33mm taller and 49mm deeper than Emotiva Airmotiv B1+.
Below you can see the front view size comparison of Emotiva Airmotiv B1+ and Polk ES15 in scale.
Comparison image of Emotiva Airmotiv B1+ and Polk ES15 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 Emotiva Airmotiv B1+ is approximately 380.1cm2 / 58.9inch2 and base area of the Polk ES15 is approximately 499.9cm2 / 77.5inch2. The Airmotiv B1+ requires 24% less surface area than the ES15 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 Emotiva Airmotiv B1+ and Polk ES15 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 Emotiva Airmotiv B1+ weighs 4.00kg / 8.8lbs and the Polk ES15 weighs 5.91kg / 13lbs. This makes the ES15 48% heavier than the Airmotiv B1+.
Here is a comparison of how Airmotiv B1+ and ES15'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 ES15?
Here are the items that come with the ES15:
- 2 Bookshelf loudspeakers
- 2 Grille (attached)
- 8 Self-adhesive rubber feet
- Wall-mount template
- Owners Manual
- Online Product Registration
 Sensitivity |
86 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Height |
274mm
vs
307mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
380cm2
vs
499cm2
|
Takes less floor space |
 Max Input Power |
100 watts
vs
70 watts
|
Handle more power from your amplifier |
 Low Frequency Response |
44 Hz
vs
48 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
28k Hz
|
Generates higher frequency |
| General |
Emotiva Airmotiv B1+ |
Polk Audio Signature Elite ES15 |
| Brand |
Emotiva |
Polk Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
Up to 70 watts |
20-100 watts |
| Sensitivity |
86 dB |
85 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
48 Hz – 28 kHz |
44-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5.25" |
| Woofer Composition |
woven fiber cone |
Mica-reinforced polypropylene |
| Woofer Surround Material |
SBR |
Butyl rubber |
| Tweeter Size |
25×32 mm" |
1" |
| Tweeter Type |
folded ribbon |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2000Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
274.0mm (10.8") |
307.0mm (12.1") |
| Width |
181.0mm (7.1") |
193.0mm (7.6") |
| Depth |
210.0mm (8.3") |
259.0mm (10.2") |
| Weight |
4.00kg (8.8lbs) |
5.91kg (13lbs) |
| Enclosure |
Bass reflex |
Bass Reflex |
| Finish |
HDF |
MDF, Wood-grain vinyl |
| Available Colors |
Black |
Black,White,Walnut |
| Mounting Bracket |
|
Keyhole |
| Recommended Stand Height |
n/a |
24-28" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
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 ES15 digs deeper - 44Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs |
evenly matched |
Similar sensitivity (86dB vs 85dB) - both want much the same power. |
| Headroom |
B |
Polk ES15 takes more power (100W vs 70W) - more in hand in a big room. |
| Size |
depends |
Emotiva Airmotiv B1+ is easier to place; Polk ES15 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability |
depends |
Neither adds bi-amping, a sub output or height drivers. Polk ES15 sits in a wider range (12 models), so a matched surround system is easier later. |
| Price |
evenly matched |
Much the same money ($299 vs $299 a pair). |
A Emotiva Airmotiv B1+
B Polk ES15
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 ES15 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. Match it to your room: we rate Emotiva Airmotiv B1+ the better fit for near-field listening; elsewhere the two are rated the same. In a large or open-plan room, Polk ES15 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Emotiva Airmotiv B1+ 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.