In this review, we will be comparing Motion 40i 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 40i and B&W 603 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan 40i | B&W 603 |
|---|
| Brand | MartinLogan
United States · founded 1982 | Bowers Wilkins
United Kingdom · founded 1966 |
|---|
| Design | 3-way | 3-way |
|---|
| Tweeter | 1.0 x 1.4" Folded Motion | 1" |
|---|
| Midrange | 5.5" | 6" |
|---|
| Woofer | 2 x 6.5" Aluminum | 2 x 6.5" Paper |
|---|
| Frequency response | 40-25k Hz | 48-28k Hz |
|---|
| Sensitivity | 92 dB | 88.5 dB |
|---|
| Impedance | 4 ohms | 8 ohms |
|---|
| Power range | 20-300 watts | 30-200 watts |
|---|
| Weight | 20.40kg / 44.9lbs | 24.14kg / 53.1lbs |
|---|
| Dimensions (H x W x D) | 41-1/2" x 7-9/16" x 13-1/16"
1055.0 x 193.0 x 332.0mm | 38.7" x 7.4" x 13.3"
985.0 x 190.0 x 340.0mm |
|---|
What size room are the MartinLogan 40i 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 40i |
B&W 603 |
| Near-field |
Bad |
Bad |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Average |
Good |
| Large Room |
Good |
Good |
| Very Large Room |
Average |
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
Both Motion 40i and BW 603 are 3-way speakers.
MartinLogan 40iB&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 40i |
B&W 603 |
|
Driver Setup
|
3-way
|
3-way
|
|
Tweeter
|
1.0 x 1.4-inch
|
1-inch
|
|
Midrange
|
1 x 5.5-inch |
1 x 6-inch |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
Motion 40i features a 1.0 x 1.4" Folded Motion Tweeter, a 5.5" Midrange and 2 x 6.5" Aluminum Woofer with a Crossover frequency at 500Hz and 2600Hz. On the other hand, the BW 603 features a 1" Tweeter, a 6" Midrange and 2 x 6.5" Paper Woofer.
Frequency Response
Motion 40i has a frequency range of 40-25k Hz whereas BW 603 has a frequency range of 48-28k Hz. With a minimum frequency of 40Hz, the Motion 40i 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
Motion 40i is a 4 ohms speaker compared to the BW 603 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 40i can provide this impedance level.
These two speakers also have different sensitivity levels. Motion 40i sensitivity is rated at 92 dB and the BW 603's is rated at 88.5 dB. This 3 dB difference makes the MartinLogan 40i 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.
Motion 40i can handle a max power of 300 watts RMS, whereas BW 603 has a max power handling value of 200 watts RMS, 100 watts less than the Motion 40i.
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 40i and BW 603 features dual binding post speaker terminals for bi-amping or bi-wiring.
MartinLogan 40i's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both Motion 40i and BW 603 have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
MartinLogan 40i 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 40i's and B&W 603's external dimensions. MartinLogan 40i has external dimensions of 1055.0 x 193.0 x 332.0mm (41-1/2 x 7-9/16 x 13-1/16inch) whereas B&W 603 has external dimensions of 985.0 x 190.0 x 340.0mm (38.7 x 7.4 x 13.3inch).
B&W 603 is 3mm narrower and 70mm shorter than MartinLogan 40i but it is also 8mm deeper.
Below you can see the front view size comparison of MartinLogan 40i and B&W 603 in scale.
Comparison image of MartinLogan 40i 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 40i is approximately 640.8cm2 / 99.3inch2 and base area of the B&W 603 is approximately 646.0cm2 / 100.1inch2. The Motion 40i requires 1% less surface area than the BW 603 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 40i weighs 20.40kg / 44.9lbs and the B&W 603 weighs 24.14kg / 53.1lbs. This makes the BW 603 18% heavier than the Motion 40i.
Here is a comparison of how Motion 40i 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 40i?
Here are the items that are included inside the box of Motion 40i:
- Floorstanding loudspeaker
- 2 Grilles
- 4 Rubber feet (pre-installed)
- 4 Spike feet (w/ nuts attached)
- Users Manual
- Warranty/Registration Information
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 |
300 watts
vs
200 watts
|
Handle more power from your amplifier |
 Sensitivity |
92 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
40 Hz
vs
48 Hz
|
Generates deeper bass |
 Base Surface Area |
640cm2
vs
646cm2
|
Takes less floor space |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
 High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
 Height |
985mm
vs
1055mm
|
Easier to fit in smaller spaces |
| General |
MartinLogan Motion 40i |
Bowers & Wilkins 603 |
| Brand |
MartinLogan |
Bowers Wilkins |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-300 watts |
30-200 watts |
| Sensitivity |
92 dB |
88.5 dB |
| Impedance |
4 ohms |
8 ohms |
| Frequency Response |
40-25k Hz |
48-28k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Aluminum |
Paper |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1.0 x 1.4" |
1" |
| Tweeter Type |
Folded Motion |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5.5" |
6" |
| Crossover Frequency |
500Hz and 2600Hz |
n/a |
| Firing Direction |
rear |
rear |
| Suggested Break-in Period |
Allow 72 hours of break-in at 90 dB |
n/a |
Physical Specs |
|
|
| Height |
1055.0mm (41.5") |
985.0mm (38.8") |
| Width |
193.0mm (7.6") |
190.0mm (7.5") |
| Depth |
332.0mm (13.1") |
340.0mm (13.4") |
| Weight |
20.40kg (44.9lbs) |
24.14kg (53.1lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Lacquer |
MDF/Vinyl |
| Available Colors |
Gloss Black, Matt White, Red Walnut |
Black, White, Oak |
| 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 40i digs deeper - 40Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs | A | MartinLogan 40i is more sensitive (92dB vs 89dB), so it goes louder on the same amplifier. |
| Amplifier match | B | B&W 603 is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | A | MartinLogan 40i takes more power (300W vs 200W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | MartinLogan 40i: bi-amping; B&W 603: bi-amping. MartinLogan 40i sits in a wider range (18 models), so a matched surround system is easier later. |
A MartinLogan 40i 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 40i 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 40i 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.