In this review, we will be comparing Motion 15 and RP-400M, two Passive Bookshelf speakers from MartinLogan and Klipsch.
Let's have a brief look at the main features
of MartinLogan 15 and Klipsch RP-400M first before getting into our more
detailed comparison.
| Key Specs | MartinLogan 15 | Klipsch RP-400M |
|---|
| Brand | MartinLogan
United States · founded 1982 | Klipsch
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1.0 x 1.4" Folded Motion | 1" Tractrix Horn |
|---|
| Woofer | 5.25" Aluminum | 4" Cerametallic |
|---|
| Frequency response | 60-25k Hz | 52-25k Hz |
|---|
| Sensitivity | 92 dB | 93 dB |
|---|
| Impedance | 5 ohms | 8 ohms |
|---|
| Power range | 20-200 watts | up to 50 watts |
|---|
| Weight | 5.40kg / 11.9lbs | 4.10kg / 9lbs |
|---|
| Dimensions (H x W x D) | 11.4" x 6.8" x 9.4"
290.0 x 173.0 x 240.0mm | 11.7" x 5.6" x 7.5"
298.0 x 144.0 x 191.0mm |
|---|
What size room are the MartinLogan 15 and Klipsch RP-400M 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* |
MartinLogan 15 |
Klipsch RP-400M |
| Near-field |
Poor |
Good |
| Small Room |
Average |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Poor |
| Very Large Room |
Poor |
No way |
(* 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.
Drivers
Both Motion 15 and RP-400M are 2-way speakers.
MartinLogan 15Klipsch RP-400M
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
MartinLogan 15 |
Klipsch RP-400M |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 4-inch
|
Motion 15 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 RP-400M features a 1" Tractrix Horn Tweeter and 1 x 4" Cerametallic Woofer with a Crossover frequency at 1500Hz.
Frequency Response
Motion 15 has a frequency range of 60-25k Hz whereas RP-400M has a frequency range of 52-25k Hz. With a minimum frequency of 52Hz, the RP-400M can go significantly deeper on the low side and provide stronger bass compared to the Motion 15's min frequency of 60Hz.
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
Motion 15 is a 5 ohms speaker compared to the RP-400M which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. Motion 15 sensitivity is rated at 92 dB and the RP-400M's is rated at 93 dB. This 1 dB difference makes the Klipsch RP-400M a more sensitive speaker compared to MartinLogan 15, 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.
Motion 15 can handle a max power of 200 watts RMS, whereas RP-400M has a max power handling value of 50 watts RMS, 150 watts less than the Motion 15.
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
Motion 15 features Single binding posts type posts and RP-400M has a Single binding posts type posts. None of these speakers feature bi-amping/bi-wiring.
Klipsch RP-400M's Single binding posts terminals
Cabinet Type and Port Position
Both Motion 15 and RP-400M 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.
Klipsch RP-400M Tractrix horn-shaped 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 MartinLogan 15's and Klipsch RP-400M's external dimensions. MartinLogan 15 has external dimensions of 290.0 x 173.0 x 240.0mm (11.4 x 6.8 x 9.4inch) whereas Klipsch RP-400M has external dimensions of 298.0 x 144.0 x 191.0mm (11.7 x 5.6 x 7.5inch).
Klipsch RP-400M is 29mm narrower and 49mm less deeper than MartinLogan 15 but it is also 8mm taller.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
MartinLogan 15 needs about 51% more floor or shelf area. MartinLogan 15 is 49mm deeper, so it stands that much further out from the wall.
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 15 is approximately 415.2cm2 / 64.4inch2 and base area of the Klipsch RP-400M is approximately 275.0cm2 / 42.6inch2. The Motion 15 requires 51% more surface area than the RP-400M 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 MartinLogan 15 weighs 5.40kg / 11.9lbs and the Klipsch RP-400M weighs 4.10kg / 9lbs. This makes the Motion 15 32% heavier than the RP-400M.
Here is a comparison of how Motion 15 and RP-400M'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 15?
Here are the items that are included inside the box of Motion 15:
- Bookshelf loudspeaker
- Grille
- 4 Rubber feet
- Users Manual
- Warranty/Registration Information
What's in the Box of Klipsch RP-400M?
Here are the items that come with the RP-400M:
- 2 Bookshelf loudspeakers
- 2 Grilles (installed)
- 8 Self-adhesive rubber feet
- User Manual
- Important Safety Instructions
- Warranty Information
 Max Input Power |
200 watts
vs
50 watts
|
Handle more power from your amplifier |
 Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
 Height |
290mm
vs
298mm
|
Easier to fit in smaller spaces |
 Sensitivity |
93 dB
vs
92 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
5 ohms
|
Less selective with amplifiers |
|
Low Frequency Response |
52 Hz
vs
60 Hz
|
Generates deeper bass |
 Mounting Bracket |
Yes
vs
No
|
Allows mounting on walls |
 Base Surface Area |
275cm2
vs
415cm2
|
Takes less floor space |
 Price per pair* |
399USD
vs
800USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Motion 15 |
Klipsch Reference Premiere RP-400M |
| Brand |
MartinLogan |
Klipsch |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-200 watts |
up to 50 watts |
| Sensitivity |
92 dB |
93 dB |
| Impedance |
5 ohms |
8 ohms |
| Frequency Response |
60-25k Hz |
52-25k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4" |
| Woofer Composition |
Aluminum |
Cerametallic |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1.0 x 1.4" |
1" |
| Tweeter Type |
Folded Motion |
Tractrix Horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2700Hz |
1500Hz |
| 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") |
298.0mm (11.7") |
| Width |
173.0mm (6.8") |
144.0mm (5.7") |
| Depth |
240.0mm (9.4") |
191.0mm (7.5") |
| Weight |
5.40kg (11.9lbs) |
4.10kg (9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Piano Lacquer |
MDF/Wood-grain vinyl |
| Available Colors |
Gloss Black, Matt White, Red Walnut |
Ebony, Walnut, Piano Black |
| Mounting Bracket |
No |
Keyhole |
| Recommended Stand Height |
24-30" |
28-30" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Yrs w/ Registration |
5 Years |
| Labor Warranty |
5 Yrs w/ Registration |
5 Years |
These sit in different price classes - MartinLogan 15 costs roughly 2x what Klipsch RP-400M does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | B | Klipsch RP-400M digs deeper - 52Hz against 60Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (92dB vs 93dB) - both want much the same power. |
| Amplifier match | B | Klipsch RP-400M is the easier load at 8 ohms. |
| Headroom | A | MartinLogan 15 takes more power (200W vs 50W) - more in hand in a big room. |
| Size | depends | Klipsch RP-400M is easier to place; MartinLogan 15 is bigger, which usually goes with fuller bass. Your room decides. |
| Price | B | Klipsch RP-400M is cheaper - $399 against $800, about 50% less; arguably a different class. |
A MartinLogan 15 B Klipsch RP-400M
depends neither is better in the abstract - it turns on your room, your system 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?
Klipsch RP-400M 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 60Hz anyway, so judge these on the other rows instead. Match it to your room: we rate MartinLogan 15 the better fit for a mid-size room and a large room, and Klipsch RP-400M for near-field listening and a small room.
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.