In this review, we will be comparing Airmotiv B2+ and S15, two Passive Bookshelf speakers from Emotiva and Polk Audio.
Let's have a brief look at the main features
of Emotiva Airmotiv B2+ and Polk S15 first before getting into our more
detailed comparison.
Emotiva Airmotiv B2+ Key Specs
- 2-way Design
- 25×32 mm" folded ribbon Tweeter
- 6.25" woven fiber cone Woofer
- 40-28k Hz Frequency Response
- 86 dB Sensitivity
- Impedance: 4ohms
- Power Range:Up to 125watts
- Weight:7.10kg
- Dimensions (H x W x D): 324.0" x 8-1/2" x 11-1/2"( 324.0 x 216.0 x 293.0mm )
Polk S15 Key Specs
- 2-way Design
- 1" Dome Tweeter
- 5.25" Mica-reinforced polypropylene Woofer
- 50-40k Hz Frequency Response
- 88 dB Sensitivity
- Impedance: 8ohms
- Power Range:20-100watts
- Weight:5.90kg
- Dimensions (H x W x D): 304.8" x 7.4" x 10.2"( 304.8 x 190.0 x 260.4mm )
What size room are the Emotiva Airmotiv B2+ 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* |
Emotiva Airmotiv B2+ |
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.)
In the following sections, we will get into more detail in order to better understand how the Emotiva Airmotiv B2+ 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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through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Airmotiv B2+ and S15 are 2-way speakers.
| Driver |
Emotiva Airmotiv B2+ |
Polk S15 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
25×32 mm-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.25-inch
|
1 x 5.25-inch
|
Airmotiv B2+ features a 25×32 mm" folded ribbon Tweeter and 1 x 6.25" woven fiber cone Woofer with a Crossover frequency at 2000Hz. 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
Airmotiv B2+ has a frequency range of 40-28k Hz whereas S15 has a frequency range of 50-40k Hz. With a minimum frequency of 40Hz, the Airmotiv B2+ can go significantly deeper on the low side and provide stronger bass compared to 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
Airmotiv B2+ is a 4 ohms speaker compared to the S15 which has a nominal impedance of 8 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 Airmotiv B2+ can provide this impedance level.
These two speakers also have different sensitivity levels. Airmotiv B2+ sensitivity is rated at 86 dB and the S15's is rated at 88 dB. This 2 dB difference makes the Polk S15 a more sensitive speaker compared to Emotiva Airmotiv B2+, 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. 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.
Airmotiv B2+ can handle a max power of 125 watts RMS from the amp the whereas S15 has a max power handling value of 100 watts RMS, 25 watts less than the Airmotiv B2+.
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
Airmotiv B2+ features Binding post posts which make bi-amping or bi-wiring possible. S15 has a Pair of Binding Posts - Gold Plated which doesn't feature bi-amping/bi-wiring.
Emotiva Airmotiv B2+'s Binding post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both Airmotiv B2+ 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.
Emotiva Airmotiv B2+ Port
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 Emotiva Airmotiv B2+'s and Polk S15's external dimensions. Emotiva Airmotiv B2+ has external dimensions of 324.0 x 216.0 x 293.0mm ( 12-3/4-inch x 8-1/2-inch x 11-1/2-inch) whereas Polk S15 has external dimensions of 304.8 x 190.0 x 260.4mm ( 12.0 x 7.4 x 10.2inch) .
Emotiva Airmotiv B2+ is clearly the larger of the two speakers. Its body is 26mm wider, 19.2mm taller and 32.6mm deeper than Polk S15.
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 B2+ is approximately 632.9cm2 / 98.1inch2 and base area of the Polk S15 is approximately 494.8cm2 / 76.7inch2. The Airmotiv B2+ requires 28% more surface area than the S15 which gives it a small disadvantage on placement in tight spaces.