In this review, we will be comparing ESL and RTi A5, two Passive Floor-standing speakers from MartinLogan and Polk Audio.
Let's have a brief look at the main features
of MartinLogan ESL and Polk RTi A5 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan ESL | Polk RTi A5 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 8.6x34" curved electrostatic transducer | 1" |
|---|
| Woofer | 8" high-excursion paper cone | 2 x 6.5" Polymer composite |
|---|
| Frequency response | 42-22k Hz | 40-26k Hz |
|---|
| Sensitivity | 91 dB | 90 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | 20-300 watts | 20-250 watts |
|---|
| Weight | 16.14kg / 35.5lbs | 18.18kg / 40lbs |
|---|
| Dimensions (H x W x D) | 53-1/8" x 9-5/16" x 16-1/2"
1350.0 x 237.0 x 420.0mm | 39-5/8" x 10-9/16" x 15-7/8"
1007.0 x 269.0 x 404.0mm |
|---|
What size room are the MartinLogan ESL and Polk RTi A5 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 ESL |
Polk RTi A5 |
| 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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Drivers
Both ESL and RTi A5 are 2-way speakers.
MartinLogan ESLPolk RTi A5
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
MartinLogan ESL |
Polk RTi A5 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
8.6x34-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 8-inch
|
2 x 6.5-inch
|
ESL features a 8.6x34" curved electrostatic transducer Tweeter and 1 x 8" high-excursion paper cone Woofer. On the other hand, the RTi A5 features a 1" Tweeter and 2 x 6.5" Polymer composite Woofer.
Frequency Response
ESL has a frequency range of 42-22k Hz whereas RTi A5 has a frequency range of 40-26k Hz. With a minimum frequency of 40Hz, the RTi A5 can go slightly deeper then the ESL's min frequency of 42Hz.
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
ESL is a 6 ohms speaker compared to the RTi A5 which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. ESL sensitivity is rated at 91 dB and the RTi A5's is rated at 90 dB. This 1 dB difference makes the MartinLogan ESL a more sensitive speaker compared to Polk RTi A5, 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.
ESL can handle a max power of 300 watts RMS, whereas RTi A5 has a max power handling value of 250 watts RMS, 50 watts less than the ESL.
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
RTi A5 features 5-way post posts which make bi-amping or bi-wiring possible. ESL has a Spring post which doesn't feature bi-amping/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 MartinLogan ESL's and Polk RTi A5's external dimensions. MartinLogan ESL has external dimensions of 1350.0 x 237.0 x 420.0mm (53-1/8 x 9-5/16 x 16-1/2inch) whereas Polk RTi A5 has external dimensions of 1007.0 x 269.0 x 404.0mm (39-5/8 x 10-9/16 x 15-7/8inch).
Polk RTi A5 is 343mm shorter and 16mm less deeper than MartinLogan ESL but it is also 32mm wider.
Below you can see the front view size comparison of MartinLogan ESL and Polk RTi A5 in scale.
Comparison image of MartinLogan ESL and Polk RTi A5 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 ESL is approximately 995.4cm2 / 154.3inch2 and base area of the Polk RTi A5 is approximately 1086.8cm2 / 168.5inch2. The ESL requires 8% less surface area than the RTi A5 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 ESL weighs 16.14kg / 35.5lbs and the Polk RTi A5 weighs 18.18kg / 40lbs. This makes the RTi A5 13% heavier than the ESL.
Here is a comparison of how ESL and RTi A5'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 MartinLogan ESL?
Here are the items that are included inside the box of ESL:
- Floor-standing hybrid electrostatic loudspeaker
- AC power adapter (w/ attached 10-feet DC cord)
- Cloth grille (installed)
- 4 Pre-installed feet
- Users Manual (En/Fr)
- Product Registration Card
What's in the Box of Polk RTi A5?
Here are the items that come with the RTi A5:
- Cherry floor-standing speaker
- Detachable black cloth grille
- 4 Screw-on spike feet
- Owners Manual
- Online registration sheet
- Polk Audio product brochure
 Max Input Power |
300 watts
vs
250 watts
|
Handle more power from your amplifier |
 Sensitivity |
91 dB
vs
90 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
8 inches
vs
6.5 inches
|
Larger woofer |
 Base Surface Area |
995cm2
vs
1086cm2
|
Takes less floor space |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
|
Number of Woofers |
2
vs
1
|
More woofers |
|
Low Frequency Response |
40 Hz
vs
42 Hz
|
Generates deeper bass |
 High Frequency Response |
26k Hz
vs
22k Hz
|
Generates higher frequency |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
1007mm
vs
1350mm
|
Easier to fit in smaller spaces |
| General |
MartinLogan ElectroMotion ESL |
Polk Audio RTi A5 |
| Brand |
MartinLogan |
Polk Audio |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-300 watts |
20-250 watts |
| Sensitivity |
91 dB |
90 dB |
| Impedance |
6 ohms |
8 ohms |
| Frequency Response |
42-22k Hz |
40-26k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
8" |
6.5" |
| Woofer Composition |
high-excursion paper cone |
Polymer composite |
| Woofer Surround Material |
Rubber |
Butyl Rubber |
| Tweeter Size |
8.6x34" |
1" |
| Tweeter Type |
curved electrostatic transducer |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
1350.0mm (53.1") |
1007.0mm (39.6") |
| Width |
237.0mm (9.3") |
269.0mm (10.6") |
| Depth |
420.0mm (16.5") |
404.0mm (15.9") |
| Weight |
16.14kg (35.5lbs) |
18.18kg (40lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Composite |
Real wood veneer |
| Available Colors |
Black |
Cherry |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
Yes |
Other |
|
|
| Parts Warranty |
5 Yrs w/ Registration |
5 Years |
| Labor Warranty |
5 Yrs w/ Registration |
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 |
evenly matched |
Much the same reach (42Hz vs 40Hz). |
| Amplifier needs |
evenly matched |
Similar sensitivity (91dB vs 90dB) - both want much the same power. |
| Amplifier match |
B |
Polk RTi A5 is the easier load at 8 ohms. |
| Headroom |
evenly matched |
Similar power handling (300W vs 250W). |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Expandability |
B |
Polk RTi A5: bi-amping. |
A MartinLogan ESL
B Polk RTi A5
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?
Polk RTi A5 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does.
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.