In this review, we will be comparing Motion F20 and R700, two Passive Floor-standing speakers from MartinLogan and Polk Audio.
Let's have a brief look at the main features
of MartinLogan Motion F20 and Polk R700 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Motion F20 | Polk R700 |
|---|
| Design | 3-way | 3-way |
|---|
| Tweeter | 1.0 x 1.4" Folded Motion Ribbon | 1" Pinnacle Ring Radiator |
|---|
| Midrange | 5.5" | 6.5" |
|---|
| Woofer | 2 x 5.5" Aluminum | 2 x 8" Polypropylene |
|---|
| Frequency response | 35-25k Hz | 38-38k Hz |
|---|
| Sensitivity | 92 dB | 88 dB |
|---|
| Impedance | 4 ohms | 8 ohms |
|---|
| Power range | 20-300 watts | 50-300 watts |
|---|
| Weight | 27.20kg / 59.8lbs | 35.90kg / 79lbs |
|---|
| Dimensions (H x W x D) | 44-3/4" x 11-3/4" x 14-1/4"
1127 x 298 x 362mm | 45" x 12.6" x 16.9"
1143.8 x 320.7 x 428.3mm |
|---|
What size room are the MartinLogan Motion F20 and Polk R700 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 |
Polk R700 |
| 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 R700 are 3-way speakers.
MartinLogan Motion F20Polk R700
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 |
Polk R700 |
|
Driver Setup
|
3-way
|
3-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1-inch
|
|
Midrange
|
1 x 5.5-inch |
1 x 6.5-inch |
|
Woofer
|
2 x 5.5-inch
|
2 x 8-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 R700 features a 1" Pinnacle Ring Radiator Tweeter, a 6.5" Midrange and 2 x 8" Polypropylene Woofer with a Crossover frequency at 350Hz and 2700Hz.
Frequency Response
Motion F20 has a frequency range of 35-25k Hz whereas R700 has a frequency range of 38-38k Hz. With a minimum frequency of 35Hz, the Motion F20 can go slightly deeper then the R700's min frequency of 38Hz.
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 R700 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 R700's is rated at 88 dB. This 4 dB difference makes the MartinLogan Motion F20 a more sensitive speaker compared to Polk R700, 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.
Both handle the same maximum of 300 watts RMS, though Motion F20 is rated 20-300 watts and R700 50-300 watts.
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 R700 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
Polk R700's Post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both Motion F20 and R700 have bottom firing ports.
Polk R700 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 Polk R700'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 Polk R700 has external dimensions of 1143.8 x 320.7 x 428.3mm (45 x 12.6 x 16.9inch).
Polk R700 is clearly the larger of the two speakers. Its body is 22.7mm wider, 16.8mm taller and 66.3mm deeper than MartinLogan Motion F20.
Below you can see the front view size comparison of MartinLogan Motion F20 and Polk R700 in scale.
Comparison image of MartinLogan Motion F20 and Polk R700 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 Polk R700 is approximately 1373.6cm2 / 212.9inch2. The Motion F20 requires 21% less surface area than the R700 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 MartinLogan Motion F20 weighs 27.20kg / 59.8lbs and the Polk R700 weighs 35.90kg / 79lbs. This makes the R700 32% heavier than the Motion F20.
Here is a comparison of how Motion F20 and R700'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 Polk R700?
Here are the items that come with the R700:
- Floorstanding loudspeaker
- 4 Outrigger feet (pre-installed)
- 4 Rubber feet (pre-installed)
- 4 Spike feet (pre-installed)
- Grille
- Hex-key
- Owner's Manual
- Online Registration
 Sensitivity |
92 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
35 Hz
vs
38 Hz
|
Generates deeper bass |
 Height |
1127mm
vs
1143mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1078cm2
vs
1373cm2
|
Takes less floor space |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
|
Woofer Size |
8 inches
vs
5.5 inches
|
Larger woofer |
 High Frequency Response |
38k Hz
vs
25k Hz
|
Generates higher frequency |
 Price per pair* |
2198USD
vs
3498USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Motion F20 |
Polk Audio Reserve R700 |
| Brand |
MartinLogan |
Polk Audio |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-300 watts |
50-300 watts |
| Sensitivity |
92 dB |
88 dB |
| Impedance |
4 ohms |
8 ohms |
| Impedance |
n/a |
3.6 ohms |
| Frequency Response |
35-25k Hz |
38-38k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5.5" |
8" |
| Woofer Composition |
Aluminum |
Polypropylene |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1.0 x 1.4" |
1" |
| Tweeter Type |
Folded Motion Ribbon |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5.5" |
6.5" |
| Crossover Frequency |
230Hz and 2600Hz |
350Hz and 2700Hz |
| Firing Direction |
bottom |
bottom |
| Suggested Break-in Period |
Allow 72 hours of break-in |
n/a |
Physical Specs |
|
|
| Height |
1127.0mm (44.4") |
1143.8mm (45") |
| Width |
298.0mm (11.7") |
320.7mm (12.6") |
| Depth |
362.0mm (14.3") |
428.3mm (16.9") |
| Weight |
27.20kg (59.8lbs) |
35.90kg (79lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF/Vinyl |
| Available Colors |
Gloss Black, Walnut, and Satin White |
Black, Walnut, White |
| 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 |
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 |
A |
MartinLogan Motion F20 digs deeper - 35Hz against 38Hz. A subwoofer would even that out. |
| Amplifier needs |
A |
MartinLogan Motion F20 is more sensitive (92dB vs 88dB), so it goes louder on the same amplifier. |
| Amplifier match |
B |
Polk R700 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 300W). |
| Size |
depends |
MartinLogan Motion F20 is easier to place; Polk R700 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability |
depends |
MartinLogan Motion F20: bi-amping; Polk R700: bi-amping. Polk R700 sits in a wider range (10 models), so a matched surround system is easier later. |
| Price |
B |
Polk R700 is cheaper - $2,198 against $3,498, about 37% less. |
A MartinLogan Motion F20
B Polk R700
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 is ahead, but only on 1 of the measured areas, and it costs about 37% more. That is a lot of money for a narrow margin on paper - Polk R700 looks like the sensible buy unless something else about the MartinLogan Motion F20 appeals to you. If your amplifier is modest, vintage or valve-based, MartinLogan Motion F20 is the safer partner - the other will want more current or more watts to sound its best. Think about the whole system, not just the speakers: the roughly $1,300 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
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.