In this review, we will be comparing R6 Meta and Motion XT C100, two Passive Center Channel speakers from KEF and MartinLogan.
Let's have a brief look at the main features
of KEF R6 Meta and MartinLogan Motion XT C100 first before getting into our more
detailed comparison.
| Key Specs | KEF R6 Meta | MartinLogan Motion XT C100 |
|---|
| Design | 3-way | 2-way |
|---|
| Uni-Q driver | 12th Generation Uni-Q | — |
|---|
| Tweeter | 1" Hard-Dome | 1.25 x 2.4" Folded Motion XT |
|---|
| Midrange | 5" | — |
|---|
| Woofer | 2 x 6.5" Hybrid Aluminum | 2 x 6.5" Aluminum |
|---|
| Frequency response | 65-28k Hz | 42-25k Hz |
|---|
| Sensitivity | 88 dB | 93 dB |
|---|
| Impedance | 4 ohms | 5 ohms |
|---|
| Power range | 15-250 watts | 20-300 watts |
|---|
| Weight | 17.82kg / 39.2lbs | 15.40kg / 33.9lbs |
|---|
| Dimensions (H x W x D) | 7-15/16" x 24-5/8" x 13-5/16"
202.0 x 626.0 x 339.0mm | 8" x 24" x 14-1/2"
203 x 610 x 368mm |
|---|
What size room are the KEF R6 Meta and MartinLogan Motion XT C100 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* |
KEF R6 Meta |
MartinLogan Motion XT C100 |
| Near-field |
Poor |
Poor |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Good |
Good |
| Large Room |
Good |
Good |
| Very Large Room |
Average |
Average |
(* 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.
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Drivers
One of the fundamental differences between these two speakers is that R6 Meta is a 3-way design whereas the Motion XT C100 is a 2-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
KEF R6 MetaMartinLogan Motion XT C100
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
KEF R6 Meta |
MartinLogan Motion XT C100 |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1-inch
|
1.25 x 2.4-inch
|
|
Midrange
|
1 x 5-inch |
- |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
R6 Meta features a 1" Aluminum with MAT absorber Hard-Dome Tweeter, a 5" Midrange and 2 x 6.5" Hybrid Aluminum Woofer with a Crossover frequency at 500Hz and 2400Hz. On the other hand, the Motion XT C100 features a 1.25 x 2.4" Folded Motion XT Tweeter and 2 x 6.5" Aluminum Woofer with a Crossover frequency at 1300Hz and 2500Hz.
Frequency Response
R6 Meta has a frequency range of 65-28k Hz whereas Motion XT C100 has a frequency range of 42-25k Hz. With a minimum frequency of 42Hz, the Motion XT C100 can go significantly deeper on the low side and provide stronger bass compared to the R6 Meta's min frequency of 65Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Center Channel class in our database.
Low Frequency
Center Channel 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
R6 Meta is a 4 ohms speaker compared to the Motion XT C100 which has a nominal impedance of 5 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 R6 Meta can provide this impedance level.
These two speakers also have different sensitivity levels. R6 Meta sensitivity is rated at 88 dB and the Motion XT C100's is rated at 93 dB. This 5 dB difference makes the MartinLogan Motion XT C100 a more sensitive speaker compared to KEF R6 Meta, hence will play louder with the same amount of watts.
Sensitivity
Center Channel 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 XT C100 can handle a max power of 300 watts RMS, whereas R6 Meta has a max power handling value of 250 watts RMS, 50 watts less than the Motion XT C100.
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.
MartinLogan Motion XT C100
Input Type and Bi-Amping / Bi-Wiring
Both R6 Meta and Motion XT C100 features dual binding post speaker terminals for bi-amping or bi-wiring.
KEF R6 Meta's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring
MartinLogan Motion XT C100's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring
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 KEF R6 Meta's and MartinLogan Motion XT C100's external dimensions. KEF R6 Meta has external dimensions of 202.0 x 626.0 x 339.0mm (7-15/16-inch x 24-5/8-inch x 13-5/16-inch) whereas MartinLogan Motion XT C100 has external dimensions of 203 x 610 x 368mm (8inch x 24inch x 14-1/2inch).
KEF R6 Meta is 1mm shorter and 29mm less deeper than MartinLogan Motion XT C100 but it is also 16mm wider.
Below you can see the front view size comparison of KEF R6 Meta and MartinLogan Motion XT C100 in scale.
Comparison image of KEF R6 Meta and MartinLogan Motion XT C100 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 KEF R6 Meta is approximately 2122.1cm2 / 328.9inch2 and base area of the MartinLogan Motion XT C100 is approximately 2244.8cm2 / 347.9inch2. The R6 Meta requires 5% less surface area than the Motion XT C100 which gives it a small advantage 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 KEF R6 Meta weighs 17.82kg / 39.2lbs and the MartinLogan Motion XT C100 weighs 15.40kg / 33.9lbs. This makes the R6 Meta 16% heavier than the Motion XT C100.
Here is a comparison of how R6 Meta and Motion XT C100's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
MartinLogan Motion XT C100
What's in the Box of KEF R6 Meta?
Here are the items that are included inside the box of R6 Meta:
- 1 R2 Meta
- 1 microfiber grille
- Rubber feet
- User manual and warranty information
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
 Height |
202mm
vs
203mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
2122cm2
vs
2244cm2
|
Takes less floor space |
 Price per pair* |
1999USD
vs
2998USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
300 watts
vs
250 watts
|
Handle more power from your amplifier |
 Sensitivity |
93 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
5 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Low Frequency Response |
42 Hz
vs
65 Hz
|
Generates deeper bass |
| General |
KEF R6 Meta |
MartinLogan Motion® XT C100 |
| Brand |
KEF |
MartinLogan |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
15-250 watts |
20-300 watts |
| Sensitivity |
88 dB |
93 dB |
| Impedance |
4 ohms |
5 ohms |
| Impedance |
3.2 ohms |
n/a |
| Frequency Response |
65-28k Hz |
42-25k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Hybrid Aluminum |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1.25 x 2.4" |
| Tweeter Type |
Hard-Dome |
Folded Motion XT |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5" |
No |
| Crossover Frequency |
500Hz and 2400Hz |
1300Hz and 2500Hz |
| Firing Direction |
n/a |
rear |
| Suggested Break-in Period |
n/a |
Allow 72 hours of break-in |
Physical Specs |
|
|
| Height |
202.0mm (8") |
203.0mm (8") |
| Width |
626.0mm (24.6") |
610.0mm (24") |
| Depth |
339.0mm (13.3") |
368.0mm (14.5") |
| Weight |
17.82kg (39.2lbs) |
15.40kg (33.9lbs) |
| Enclosure |
Sealed |
Bass Reflex |
| Finish |
n/a |
MDF/Wood veneer |
| Available Colors |
Black Gloss, White Gloss, Walnut |
Gloss Black, Walnut, and Satin White |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 years |
5 Years |
| Labor Warranty |
5 years |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass |
B |
MartinLogan Motion XT C100 digs deeper - 42Hz against 65Hz. |
| Amplifier needs |
B |
MartinLogan Motion XT C100 is more sensitive (93dB vs 88dB), so it goes louder on the same amplifier. |
| Amplifier match |
B |
MartinLogan Motion XT C100 is the easier load at 5 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom |
evenly matched |
Similar power handling (250W vs 300W). |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Cabinet |
depends |
Sealed vs Ported. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Expandability |
depends |
KEF R6 Meta: bi-amping; MartinLogan Motion XT C100: bi-amping. |
| Price |
A |
KEF R6 Meta is cheaper - $1,999 against $2,998, about 33% less. |
A KEF R6 Meta
B MartinLogan Motion XT C100
depends neither is better in the abstract - it turns on your room, placement 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?
The usual trade-off: MartinLogan Motion XT C100 measures better, KEF R6 Meta costs about 33% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 65Hz anyway, which makes the cheaper KEF R6 Meta much easier to justify. If your amplifier is modest, vintage or valve-based, MartinLogan Motion XT C100 is the safer partner - the other will want more current or more watts to sound its best.
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.