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MartinLogan Motion XT B100 vs Buchardt S400 MKII Comparison

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MartinLogan Motion XT B100

Passive Bookshelf | 45-25k Hz

MartinLogan Motion® XT B100
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Buchardt S400 MKII

Passive Bookshelf | 33-40k HZ

Buchardt S400 MKII
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MartinLogan Motion XT B100 MartinLogan Motion X...
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Buchardt S400 MKII Buchardt S400 MKII
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MartinLogan Motion X...
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Buchardt S400 MKII
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MartinLogan Motion XT B100 vs Buchardt S400 MKII Speaker Comparison

In this review, we will be comparing Motion XT B100 and S400 MKII, two Passive Bookshelf speakers from MartinLogan and Buchardt.

Let's have a brief look at the main features of MartinLogan Motion XT B100 and Buchardt S400 MKII first before getting into our more detailed comparison.

MartinLogan Motion XT B100 Key Specs

  • 2-way Design
  • 1.25 x 2.4" Folded Motion XT Tweeter
  • 6.5" Kevlar Woofer
  • 45-25k Hz Frequency Response
  • 93 dB Sensitivity
  • Impedance: 4ohms
  • Power Range:20-250watts
  • Weight:9.30kg
  • Dimensions (H x W x D): 368.0" x 8" x 12-1/2"( 368 x 203 x 318mm )

Buchardt S400 MKII Key Specs

  • 2-way Design
  • 0.74" aluminum waveguide Tweeter
  • 6" paper Woofer
  • 33-40k HZ Frequency Response
  • 88 dB Sensitivity
  • Impedance: 4ohms
  • Power Range:40-200watts
  • Weight:7.50kg
  • Dimensions (H x W x D): 365.0" x 7" x 11"( 365.0 x 180.0 x 280.0mm )

What size room are the MartinLogan Motion XT B100 and Buchardt S400 MKII 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 Motion XT B100 Buchardt S400 MKII
Near-field Poor Poor
Small Room Poor Average
Mid-size Room Good Good
Large Room Good Average
Very Large Room Average Poor

(* 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 Motion XT B100 and Buchardt S400 MKII compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.


**This post contains affiliate links, and I will be compensated if you make a purchase after clicking through my links. As an Amazon Associate I earn from qualifying purchases.


Drivers

Both Motion XT B100 and S400 MKII are 2-way speakers.

Driver MartinLogan Motion XT B100 Buchardt S400 MKII
Driver Setup 2-way 2-way
Tweeter 1.25 x 2.4-inch 0.74-inch
Midrange - -
Woofer 1 x 6.5-inch 1 x 6-inch

Motion XT B100 features a 1.25 x 2.4" Folded Motion XT Tweeter and 1 x 6.5" Kevlar Woofer with a Crossover frequency at 2600Hz. On the other hand, the S400 MKII features a 0.74" fine weave soft fabric textile aluminum waveguide Tweeter and 1 x 6" paper Woofer with a Crossover frequency at 1800Hz.

Frequency Response

Motion XT B100 has a frequency range of 45-25k Hz whereas S400 MKII has a frequency range of 33-40k HZ. With a minimum frequency of 33Hz, the S400 MKII can go significantly deeper on the low side and provide stronger bass compared to the Motion XT B100's min frequency of 45Hz.

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

Motion XT B100
S400 MKII
Min
Average
Max
High Frequency

Bookshelf Speakers

MartinLogan Motion XT B100
Buchardt S400 MKII
Min
Average
Max

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 XT B100 and S400 MKII have the same Impedance of 4 ohms but where they differ is the sensitivity levels. Motion XT B100 sensitivity is rated at 93 dB and the S400 MKII's is at 88 dB. This 5 dB difference makes the MartinLogan Motion XT B100 a more sensitive speaker compared to Buchardt S400 MKII, hence will play louder with the same amount of watts.

One thing to keep in mind that the lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit comared to higher impedance speakers especially at high volume levels, so make sure the amp you pair with the Motion XT B100 and the Motion XT B100 can provide this impedance level.

Sensitivity

Bookshelf Speakers

Motion XT B100
S400 MKII
Min
Average
Max

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 XT B100 can handle a max power of 250 watts RMS from the amp the whereas S400 MKII has a max power handling value of 200 watts RMS, 50 watts less than the Motion XT B100.

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.

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 Motion XT B100's and Buchardt S400 MKII's external dimensions. MartinLogan Motion XT B100 has external dimensions of 368 x 203 x 318mm ( 14-1/2-inch x 8inch x 12-1/2inch ) whereas Buchardt S400 MKII has external dimensions of 365.0 x 180.0 x 280.0mm ( 14.4 x 7 x 11inch) .

MartinLogan Motion XT B100 is clearly the larger of the two speakers. Its body is 23mm wider, 3mm taller and 38mm deeper than Buchardt S400 MKII.

Below you can see the front view size comparison of MartinLogan Motion XT B100 and Buchardt S400 MKII in scale.

MartinLogan Motion XT B100 vs Buchardt S400 MKII Size Comparison - Front View
Comparison image of MartinLogan Motion XT B100 and Buchardt S400 MKII 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 Motion XT B100 is approximately 645.5cm2 / 100.1inch2 and base area of the Buchardt S400 MKII is approximately 504.0cm2 / 78.1inch2. The Motion XT B100 requires 28% more surface area than the S400 MKII 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:

MartinLogan Motion XT B100 vs Buchardt S400 MKII Size Comparison on a Media Console
Size Comparison image of MartinLogan Motion XT B100 and Buchardt S400 MKII 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 MartinLogan Motion XT B100 weighs 9.30kg / 20.5lbs and the Buchardt S400 MKII weighs 7.50kg / 16.5lbs. This makes the Motion XT B100 24% heavier than the S400 MKII.

Here is a comparison of how Motion XT B100 and S400 MKII's weights compare with the average, max and min weights in Passive Bookshelf class.

Weight
All Bookshelf Speakers
MartinLogan Motion XT B100
Buchardt S400 MKII
Min
Average
Max

Reasons to choose MartinLogan Motion® XT B100 over Buchardt S400 MKII
Max Input Power 250 watts vs 200 watts Handle more power from your amplifier
Sensitivity 93 dB vs 88 dB Play louder with same amount of amplification power
Woofer Size 6.5 inches vs 6 inches Larger woofer
Price per pair* 1598USD vs 2200USD costs less (*prices may change depending on the seller, location and time)

Reasons to choose Buchardt S400 MKII over MartinLogan Motion® XT B100

Low Frequency Response 33 Hz vs 45 Hz Generates deeper bass
High Frequency Response 40k Hz vs 25k Hz Generates higher frequency
Passive Radiator one 5x8-inch vs None Increases the bass performance
Height 365mm vs 368mm Easier to fit in smaller spaces
Base Surface Area 504cm2 vs 645cm2 Takes less floor space
MartinLogan Motion XT B100 vs Buchardt S400 MKII Specs Table
Detailed comparison of specifications
General MartinLogan Motion® XT B100 Buchardt S400 MKII
Brand MartinLogan Buchardt
Speaker Type Bookshelf speakers Bookshelf speakers
Power Range 20-250 watts 40-200 watts
Sensitivity 93 dB 88 dB
Impedance 4 ohms 4 ohms
Frequency Response 45-25k Hz 33-40k HZ
Drivers
Woofer Quantity 1 1
Woofer Size 6.5" 6"
Woofer Composition Kevlar paper
Woofer Surround Material Rubber n/a
Tweeter Size 1.25 x 2.4" 0.74"
Tweeter Type Folded Motion XT aluminum waveguide
Aimable Tweeter No No
Midrange Driver No No
Crossover Frequency 2600Hz 1800Hz
Firing Direction rear n/a
Suggested Break-in Period Allow 72 hours of break-in n/a
Physical Specs
Height 368.0mm (14.5") 365.0mm (14.4")
Width 203.0mm (8") 180.0mm (7.1")
Depth 318.0mm (12.5") 280.0mm (11")
Weight 9.30kg (20.5lbs) 7.50kg (16.5lbs)
Enclosure Bass Reflex Passive Radiator
Finish MDF/Wood veneer n/a
Available Colors Gloss Black, Walnut, and Satin White Black, White, Walnut, Rosewood, Light Oak
Mounting Bracket No No
Recommended Stand Height 24-28" n/a
Grille Yes Yes
Moisture Resistancy No No
Connections
Biamp Inputs Yes n/a
Other
Parts Warranty 5 Years 10 years
Labor Warranty 5 Years 10 years

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