In this review, we will be comparing Motion 35XTi and LS50, two Passive Bookshelf speakers from MartinLogan and KEF.
Let's have a brief look at the main features
of MartinLogan 35XTi and KEF LS50 first before getting into our more
detailed comparison.
MartinLogan 35XTi Key Specs
- 2-way Design
- 1.25 x 2.4" Folded Motion XT Tweeter
- 6.5" Aluminum Woofer
- 50-25k Hz Frequency Response
- 92 dB Sensitivity
- Impedance: 4ohms
- Power Range:20-250watts
- Weight:8.40kg
- Dimensions (H x W x D): 343.0" x 7.5" x 11.8"( 343.0 x 192.0 x 300.0mm )
KEF LS50 Key Specs
- 2-way Design
- 11th Generation Uni-Q Driver
- 1" Vented dome Tweeter
- 5.25" Magnesium/aluminum alloy Woofer
- 79-28k Hz Frequency Response
- 85 dB Sensitivity
- Impedance: 8ohms
- Power Range:25-100watts
- Weight:7.20kg
- Dimensions (H x W x D): 302.0" x 7.8" x 10.9"( 302.0 x 200.0 x 278.0mm )
What size room are the MartinLogan 35XTi and KEF LS50 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 35XTi |
KEF LS50 |
| Near-field |
Poor |
Average |
| Small Room |
Poor |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Good |
Poor |
| Very Large Room |
Average |
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 MartinLogan 35XTi and KEF LS50 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 Motion 35XTi and LS50 are 2-way speakers.
| Driver |
MartinLogan 35XTi |
KEF LS50 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.25 x 2.4-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.25-inch
|
Motion 35XTi features a 1.25 x 2.4" Folded Motion XT Tweeter and 1 x 6.5" Aluminum Woofer with a Crossover frequency at 2200Hz. On the other hand, the LS50 features a 1" Aluminum Vented dome Tweeter and 1 x 5.25" Magnesium/aluminum alloy Woofer with a Crossover frequency at 2200Hz.
Frequency Response
Motion 35XTi has a frequency range of 50-25k Hz whereas LS50 has a frequency range of 79-28k Hz. With a minimum frequency of 50Hz, the Motion 35XTi can go significantly deeper on the low side and provide stronger bass compared to the LS50's min frequency of 79Hz.
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 35XTi is a 4 ohms speaker compared to the LS50 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 Motion 35XTi can provide this impedance level.
These two speakers also have different sensitivity levels. Motion 35XTi sensitivity is rated at 92 dB and the LS50's is rated at 85 dB. This 7 dB difference makes the MartinLogan 35XTi a more sensitive speaker compared to KEF LS50, 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 35XTi can handle a max power of 250 watts RMS from the amp the whereas LS50 has a max power handling value of 100 watts RMS, 150 watts less than the Motion 35XTi.
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 35XTi features Custom 5-way bi-wire tool-less binding posts posts which make bi-amping or bi-wiring possible. LS50 has a Post which doesn't feature bi-amping/bi-wiring.
MartinLogan 35XTi's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring
KEF LS50's Post terminals
Cabinet Type and Port Position
Both Motion 35XTi and LS50 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 35XTi's and KEF LS50's external dimensions. MartinLogan 35XTi has external dimensions of 343.0 x 192.0 x 300.0mm ( 13.5 x 7.5 x 11.8inch) whereas KEF LS50 has external dimensions of 302.0 x 200.0 x 278.0mm ( 11.8 x 7.8 x 10.9inch) .
KEF LS50 is 41mm shorter and 22mm less deeper than MartinLogan 35XTi but it is also 8mm wider.
Below you can see the front view size comparison of MartinLogan 35XTi and KEF LS50 in scale.
Comparison image of MartinLogan 35XTi and KEF LS50 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 MartinLogan 35XTi is approximately 576.0cm2 / 89.3inch2 and base area of the KEF LS50 is approximately 556.0cm2 / 86.2inch2. The Motion 35XTi requires 4% more surface area than the LS50 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:
Size Comparison image of MartinLogan 35XTi and KEF LS50 on a Media Console