In this review, we will be comparing Motion 15i and Alpha P3, two Passive Bookshelf speakers from MartinLogan and PSB. Let's have a brief look at the main features
of MartinLogan 15i and PSB P3 first before getting into our more
detailed comparison.
What size room are the MartinLogan 15i and PSB P3 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 MartinLogan 15i and PSB P3 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 Motion 15i and Alpha P3 are 2-way speakers.
Driver |
MartinLogan 15i |
PSB P3 |
Driver Setup
|
2-way
|
2-way
|
Tweeter
|
1.0 x 1.4-inch
|
0.75-inch
|
Midrange
|
- |
- |
Woofer
|
1 x 5.25-inch
|
1 x 4.5-inch
|
Motion 15i features a 1.0 x 1.4" Folded Motion Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 2700Hz. On the other hand, the Alpha P3 features a 0.75" anodized aluminum Hard-Dome Tweeter and 1 x 4.5" Polypropylene Woofer with a Crossover frequency at 3000Hz.
Frequency Response
Motion 15i has a frequency range of 60-25k Hz whereas Alpha P3 has a frequency range of 57-21k Hz. With a minimum frequency of 57Hz, the Alpha P3 can go slightly deeper then the Motion 15i's min frequency of 60Hz.
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
Motion 15i is a 5 ohms speaker compared to the Alpha P3 which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. Motion 15i sensitivity is rated at 92 dB and the Alpha P3's is rated at 87 dB. This 5 dB difference makes the MartinLogan 15i a more sensitive speaker compared to PSB P3, 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.
Motion 15i can handle a max power of 200 watts RMS from the amp the whereas Alpha P3 has a max power handling value of 80 watts RMS, 120 watts less than the Motion 15i.
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
Motion 15i features 5-way post type posts and Alpha P3 has a 5-way post type posts. None of these speakers feature bi-amping/bi-wiring.
Cabinet Type and Port Position
Both Motion 15i and Alpha P3 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 MartinLogan 15i's and PSB P3's external dimensions. MartinLogan 15i has external dimensions of 290.0 x 173.0 x 240.0mm ( 11.4 x 6.8 x 9.4inch) whereas PSB P3 has external dimensions of 223.0 x 132.0 x 186.0mm ( 8-3/4 x 5-3/16 x 7-5/16inch) .
MartinLogan 15i is clearly the larger of the two speakers. Its body is 41mm wider, 67mm taller and 54mm deeper than PSB P3.
Below you can see the front view size comparison of MartinLogan 15i and PSB P3 in scale.
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 MartinLogan 15i is approximately 415.2cm2 / 64.4inch2 and base area of the PSB P3 is approximately 245.5cm2 / 38.1inch2. The Motion 15i requires 69% more surface area than the Alpha P3 which gives it a small disadvantage on placement in tight spaces.
Here is an another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
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 MartinLogan 15i weighs 5.40kg / 11.9lbs and the PSB P3 weighs 2.23kg / 4.9lbs. This makes the Motion 15i 142% heavier than the Alpha P3.
Here is a comparison of how Motion 15i and Alpha P3's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of MartinLogan 15i?
Here are the items that are included inside the box of Motion 15i:
Bookshelf loudspeaker Grille 4 Rubber feet Users Manual Warranty/Registration Information
What's in the Box of PSB P3?
Here are the items that come with the Alpha P3:
2 Bookshelf loudspeakers 2 Grilles 8 Self-adhesive rubber feet Quick Start Guide Warranty Card
Max Input Power |
200 watts
vs
80 watts
|
Handle more power from your amplifier |
Sensitivity |
92 dB
vs
87 dB
|
Play louder with same amount of amplification power |
Woofer Size |
5.25 inches
vs
4.5 inches
|
Larger woofer |
High Frequency Response |
25k Hz
vs
21k Hz
|
Generates higher frequency |
Nominal Impedance |
8 ohms
vs
5 ohms
|
Less selective with amplifiers |
Low Frequency Response |
57 Hz
vs
60 Hz
|
Generates deeper bass |
Height |
223mm
vs
290mm
|
Easier to fit in smaller spaces |
Base Surface Area |
245cm2 (132x186mm)
vs
415cm2 (173x240mm)
|
Takes less floor space |
Price per pair* |
279USD
vs
900USD
|
costs less (*prices may change depending on the seller, location and time) |
General |
MartinLogan Motion 15i |
PSB Alpha P3 |
Brand |
MartinLogan |
PSB |
Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
Power Range |
20-200 watts |
10-80 watts |
Sensitivity |
92 dB |
87 dB |
Impedance |
5 ohms |
8 ohms |
Impedance |
n/a |
4 ohms |
Frequency Response |
60-25k Hz |
57-21k Hz |
Drivers |
|
|
Woofer Quantity |
1 |
1 |
Woofer Size |
5.25" |
4.5" |
Woofer Composition |
Aluminum |
Polypropylene |
Woofer Surround Material |
Rubber |
Rubber |
Tweeter Size |
1.0 x 1.4" |
0.75" |
Tweeter Type |
Folded Motion |
Hard-Dome |
Aimable Tweeter |
No |
No |
Midrange Driver |
No |
No |
Crossover Frequency |
2700Hz |
3000Hz |
Firing Direction |
rear |
rear |
Suggested Break-in Period |
Allow 72 hours of break-in at 90 dB |
n/a |
Physical Specs |
|
|
Height |
290.0mm (11.4") |
223.0mm (8.8") |
Width |
173.0mm (6.8") |
132.0mm (5.2") |
Depth |
240.0mm (9.4") |
186.0mm (7.3") |
Weight |
5.40kg (11.9lbs) |
2.23kg (4.9lbs) |
Enclosure |
Bass Reflex |
Bass Reflex |
Finish |
MDF/Lacquer |
MDF, Wood-grain vinyl |
Available Colors |
Gloss Black, Matt White, Red Walnut |
Walnut,Black Ash |
Mounting Bracket |
No |
No |
Recommended Stand Height |
26-28" |
28-30" |
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 |