In this review, we will be comparing ESL X and BW 603, two Passive Floor-standing speakers from MartinLogan and Bowers Wilkins.
Let's have a brief look at the main features
of MartinLogan ESL X and B&W 603 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan ESL X | B&W 603 |
|---|
| Brand | MartinLogan
United States · founded 1982 | Bowers Wilkins
United Kingdom · founded 1966 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 8.6 x 40" curved electrostatic transducer | 1" |
|---|
| Midrange | — | 6" |
|---|
| Woofer | 2 x 8" high-excursion paper cone | 2 x 6.5" Paper |
|---|
| Frequency response | 41-22k Hz | 48-28k Hz |
|---|
| Sensitivity | 91 dB | 88.5 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | 20-400 watts | 30-200 watts |
|---|
| Weight | 23.64kg / 52lbs | 24.14kg / 53.1lbs |
|---|
| Dimensions (H x W x D) | 59-1/4" x 9-7/16" x 20-3/4"
1505.0 x 240.0 x 528.0mm | 38.7" x 7.4" x 13.3"
985.0 x 190.0 x 340.0mm |
|---|
What size room are the MartinLogan ESL X and B&W 603 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 X |
B&W 603 |
| Near-field |
Are you nuts? |
Bad |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Average |
Good |
| Large Room |
Good |
Good |
| Very Large Room |
Good |
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.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
One of the fundamental differences between these two speakers is that ESL X is a 2-way design whereas the BW 603 is a 3-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.
MartinLogan ESL XB&W 603
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 ESL X |
B&W 603 |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
8.6 x 40-inch
|
1-inch
|
|
Midrange
|
- |
1 x 6-inch |
|
Woofer
|
2 x 8-inch
|
2 x 6.5-inch
|
ESL X features a 8.6 x 40" curved electrostatic transducer Tweeter and 2 x 8" high-excursion paper cone Woofer. On the other hand, the BW 603 features a 1" Tweeter, a 6" Midrange and 2 x 6.5" Paper Woofer.
Frequency Response
ESL X has a frequency range of 41-22k Hz whereas BW 603 has a frequency range of 48-28k Hz. With a minimum frequency of 41Hz, the ESL X can go significantly deeper on the low side and provide stronger bass compared to the BW 603'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
ESL X is a 6 ohms speaker compared to the BW 603 which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. ESL X sensitivity is rated at 91 dB and the BW 603's is rated at 88.5 dB. This 2 dB difference makes the MartinLogan ESL X a more sensitive speaker compared to B&W 603, 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 X can handle a max power of 400 watts RMS, whereas BW 603 has a max power handling value of 200 watts RMS, 200 watts less than the ESL X.
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 ESL X and BW 603 features dual binding post speaker terminals for 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 MartinLogan ESL X's and B&W 603's external dimensions. MartinLogan ESL X has external dimensions of 1505.0 x 240.0 x 528.0mm (59-1/4 x 9-7/16 x 20-3/4inch) whereas B&W 603 has external dimensions of 985.0 x 190.0 x 340.0mm (38.7 x 7.4 x 13.3inch).
MartinLogan ESL X is clearly the larger of the two speakers. Its body is 50mm wider, 520mm taller and 188mm deeper than B&W 603.
Below you can see the front view size comparison of MartinLogan ESL X and B&W 603 in scale.
Comparison image of MartinLogan ESL X and B&W 603 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 X is approximately 1267.2cm2 / 196.4inch2 and base area of the B&W 603 is approximately 646.0cm2 / 100.1inch2. The ESL X requires 96% more surface area than the BW 603 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 ESL X weighs 23.64kg / 52lbs and the B&W 603 weighs 24.14kg / 53.1lbs. This makes the BW 603 2% heavier than the ESL X.
Here is a comparison of how ESL X and BW 603'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 X?
Here are the items that are included inside the box of ESL X:
- 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 B&W 603?
Here are the items that come with the BW 603:
- Floorstanding loudspeaker
- Grille
- Plinith (base)
- 2 Jumper-straps (pre-installed)
- 4 Rubber feet
- 4 Spike feet
- 4 Hex-nuts
- 4 Screws
- 4 Washers
- 4 Lock-washers
- Two-piece foam port plug
- Hex-key
- Manual
- Bowers & Wilkins brochure
- Warranty Information
 Max Input Power |
400 watts
vs
200 watts
|
Handle more power from your amplifier |
 Sensitivity |
91 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
8 inches
vs
6.5 inches
|
Larger woofer |
|
Low Frequency Response |
41 Hz
vs
48 Hz
|
Generates deeper bass |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 High Frequency Response |
28k Hz
vs
22k Hz
|
Generates higher frequency |
 Height |
985mm
vs
1505mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
646cm2
vs
1267cm2
|
Takes less floor space |
| General |
MartinLogan ElectroMotion ESL X |
Bowers & Wilkins 603 |
| Brand |
MartinLogan |
Bowers Wilkins |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-400 watts |
30-200 watts |
| Sensitivity |
91 dB |
88.5 dB |
| Impedance |
6 ohms |
8 ohms |
| Frequency Response |
41-22k Hz |
48-28k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
8" |
6.5" |
| Woofer Composition |
high-excursion paper cone |
Paper |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
8.6 x 40" |
1" |
| Tweeter Type |
curved electrostatic transducer |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
6" |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
1505.0mm (59.3") |
985.0mm (38.8") |
| Width |
240.0mm (9.4") |
190.0mm (7.5") |
| Depth |
528.0mm (20.8") |
340.0mm (13.4") |
| Weight |
23.64kg (52lbs) |
24.14kg (53.1lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Composite |
MDF/Vinyl |
| Available Colors |
Black |
Black, White, Oak |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
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 | A | MartinLogan ESL X digs deeper - 41Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs | A | MartinLogan ESL X is more sensitive (91dB vs 89dB), so it goes louder on the same amplifier. |
| Amplifier match | B | B&W 603 is the easier load at 8 ohms. |
| Headroom | A | MartinLogan ESL X takes more power (400W vs 200W) - more in hand in a big room. |
| Size | depends | B&W 603 is easier to place; MartinLogan ESL X is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | MartinLogan ESL X: bi-amping; B&W 603: bi-amping. |
A MartinLogan ESL X B B&W 603
depends neither is better in the abstract - it turns on your room, your system 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 ESL X 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. Match it to your room: we rate MartinLogan ESL X the better fit for a very large room, and B&W 603 for a mid-size room.
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.