In this review, we will be comparing Motion F20 and R7, two Passive Floor-standing speakers from MartinLogan and KEF.
Let's have a brief look at the main features
of MartinLogan Motion F20 and KEF R7 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Motion F20 | KEF R7 |
|---|
| Design | 3-way | 3-way |
|---|
| Uni-Q driver | — | 12th Generation Uni-Q |
|---|
| Tweeter | 1.0 x 1.4" Folded Motion Ribbon | 1" Dome |
|---|
| Midrange | 5.5" | 5" |
|---|
| Woofer | 2 x 5.5" Aluminum | 2 x 6.5" Hybrid Aluminum |
|---|
| Frequency response | 35-25k Hz | 48-28k Hz |
|---|
| Sensitivity | 92 dB | 88 dB |
|---|
| Impedance | 4 ohms | 8 ohms |
|---|
| Power range | 20-300 watts | 15-250 watts |
|---|
| Weight | 27.20kg / 59.8lbs | 31.40kg / 69.1lbs |
|---|
| Dimensions (H x W x D) | 44-3/4" x 11-3/4" x 14-1/4"
1127 x 298 x 362mm | 43-13/16" x 8" x 15-5/16"
1113.0 x 200.0 x 389.0mm |
|---|
What size room are the MartinLogan Motion F20 and KEF R7 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 F20 |
KEF R7 |
| Near-field |
Bad |
Bad |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Average |
Average |
| 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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through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Motion F20 and R7 are 3-way speakers.
MartinLogan Motion F20KEF R7
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
MartinLogan Motion F20 |
KEF R7 |
|
Driver Setup
|
3-way
|
3-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1-inch
|
|
Midrange
|
1 x 5.5-inch |
1 x 5-inch |
|
Woofer
|
2 x 5.5-inch
|
2 x 6.5-inch
|
Motion F20 features a 1.0 x 1.4" Folded Motion Ribbon Tweeter, a 5.5" Midrange and 2 x 5.5" Aluminum Woofer with a Crossover frequency at 230Hz and 2600Hz. On the other hand, the R7 features a 1" aluminum Dome Tweeter, a 5" Midrange and 2 x 6.5" Hybrid Aluminum Woofer with a Crossover frequency at 400Hz and 2900Hz.
Frequency Response
Motion F20 has a frequency range of 35-25k Hz whereas R7 has a frequency range of 48-28k Hz. With a minimum frequency of 35Hz, the Motion F20 can go significantly deeper on the low side and provide stronger bass compared to the R7's min frequency of 48Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing 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 F20 is a 4 ohms speaker compared to the R7 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 F20 can provide this impedance level.
These two speakers also have different sensitivity levels. Motion F20 sensitivity is rated at 92 dB and the R7's is rated at 88 dB. This 4 dB difference makes the MartinLogan Motion F20 a more sensitive speaker compared to KEF R7, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing 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 F20 can handle a max power of 300 watts RMS, whereas R7 has a max power handling value of 250 watts RMS, 50 watts less than the Motion F20.
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
Both Motion F20 and R7 features dual binding post speaker terminals for bi-amping or bi-wiring.
MartinLogan Motion F20's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring
KEF R7's Binding post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Motion F20 has a bottom firing port whereas R7 has a rear firing ports. MartinLogan Motion F20's bottom-firing port gives more flexibility in placement in regards to proximity to walls compared to KEF R7 with its rear-firing 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 Motion F20's and KEF R7's external dimensions. MartinLogan Motion F20 has external dimensions of 1127 x 298 x 362mm (44-3/4inch x 11-3/4inch x 14-1/4inch) whereas KEF R7 has external dimensions of 1113.0 x 200.0 x 389.0mm (43-13/16 x 8 x 15-5/16inch).
KEF R7 is 98mm narrower and 14mm shorter than MartinLogan Motion F20 but it is also 27mm deeper.
Below you can see the front view size comparison of MartinLogan Motion F20 and KEF R7 in scale.
Comparison image of MartinLogan Motion F20 and KEF R7 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 F20 is approximately 1078.8cm2 / 167.2inch2 and base area of the KEF R7 is approximately 778.0cm2 / 120.6inch2. The Motion F20 requires 39% more surface area than the R7 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 Motion F20 weighs 27.20kg / 59.8lbs and the KEF R7 weighs 31.40kg / 69.1lbs. This makes the R7 15% heavier than the Motion F20.
Here is a comparison of how Motion F20 and R7's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
What's in the Box of KEF R7?
Here are the items that come with the R7:
- Floorstanding loudspeaker
- Grille
- 2 Foam port plugs
- 4 Outrigger feet
- 4 Spikes
- 4 Protective discs
- 4 Screws
- 4 Washers
- Wrench
- Hex-key
- User Manual
- Warranty Information
 Max Input Power |
300 watts
vs
250 watts
|
Handle more power from your amplifier |
 Sensitivity |
92 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
35 Hz
vs
48 Hz
|
Generates deeper bass |
 Price per pair* |
3498USD
vs
4500USD
|
costs less (*prices may change depending on the seller, location and time) |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
|
Woofer Size |
6.5 inches
vs
5.5 inches
|
Larger woofer |
 High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
 Height |
1113mm
vs
1127mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
778cm2
vs
1078cm2
|
Takes less floor space |
| General |
MartinLogan Motion F20 |
KEF R7 |
| Brand |
MartinLogan |
KEF |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-300 watts |
15-250 watts |
| Sensitivity |
92 dB |
88 dB |
| Impedance |
4 ohms |
8 ohms |
| Impedance |
n/a |
3.2 ohms |
| Frequency Response |
35-25k Hz |
48-28k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5.5" |
6.5" |
| Woofer Composition |
Aluminum |
Hybrid Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1.0 x 1.4" |
1" |
| Tweeter Type |
Folded Motion Ribbon |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5.5" |
5" |
| Crossover Frequency |
230Hz and 2600Hz |
400Hz and 2900Hz |
| Firing Direction |
bottom |
rear |
| Suggested Break-in Period |
Allow 72 hours of break-in |
n/a |
Physical Specs |
|
|
| Height |
1127.0mm (44.4") |
1113.0mm (43.8") |
| Width |
298.0mm (11.7") |
200.0mm (7.9") |
| Depth |
362.0mm (14.3") |
389.0mm (15.3") |
| Weight |
27.20kg (59.8lbs) |
31.40kg (69.1lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF/Lacquer |
| Available Colors |
Gloss Black, Walnut, and Satin White |
Black Gloss, White Gloss, Walnut |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
A generation apart: MartinLogan Motion F20 is the newer design, against a 2018 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass |
A |
MartinLogan Motion F20 digs deeper - 35Hz against 48Hz. |
| Amplifier needs |
A |
MartinLogan Motion F20 is more sensitive (92dB vs 88dB), so it goes louder on the same amplifier. |
| Amplifier match |
B |
KEF R7 is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom |
evenly matched |
Similar power handling (300W vs 250W). |
| Size |
depends |
KEF R7 is easier to place; MartinLogan Motion F20 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability |
depends |
MartinLogan Motion F20: bi-amping; KEF R7: bi-amping. |
| Price |
A |
MartinLogan Motion F20 is cheaper - $3,498 against $4,500, about 22% less. |
A MartinLogan Motion F20
B KEF R7
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?
MartinLogan Motion F20 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 48Hz anyway, so judge these on the other rows instead. In a large or open-plan room, MartinLogan Motion F20 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, KEF R7 is the easier speaker to get right.
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.