In this review, we will be comparing Foundation B1 and Foundation B2, two Passive Bookshelf speakers by MartinLogan.
Let's have a brief look at the main features
of MartinLogan Foundation B1 and MartinLogan Foundation B2 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Foundation B1 | MartinLogan Foundation B2 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Folded Motion Ribbon | 1" Folded Motion Ribbon |
|---|
| Woofer | 5-1/2" Aluminum | 6-1/2" Aluminum |
|---|
| Frequency response | 48-23k Hz | 42-23k Hz |
|---|
| Sensitivity | 89 dB | 90 dB |
|---|
| Impedance | 5 ohms | 5 ohms |
|---|
| Power range | up to 100 watts | up to 100 watts |
|---|
| Weight | 5.23kg / 11.5lbs | 5.23kg / 11.5lbs |
|---|
| Dimensions (H x W x D) | 13-5/8" x 7-1/4" x 9-1/2"
347.0 x 185.0 x 242.0mm | 15" x 7-3/4" x 9-1/2"
381.0 x 197.0 x 242.0mm |
|---|
Foundation B1 and Foundation B2 are members of MartinLogan's Foundation series of speakers. Below you can find the loudspeakers from this series.
MartinLogan Foundation Series
History
What size room are the MartinLogan Foundation B1 and MartinLogan Foundation B2 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 Foundation B1 |
MartinLogan Foundation B2 |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
Bad |
(* 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 Foundation B1 and Foundation B2 are 2-way speakers.
MartinLogan Foundation B1MartinLogan Foundation B2
Tweeter
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
MartinLogan Foundation B1 |
MartinLogan Foundation B2 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-1/2-inch
|
1 x 6-1/2-inch
|
Foundation B1 features a 1" Gen2 Obsidian Folded Motion Ribbon Tweeter and 1 x 5-1/2" Aluminum Woofer with a Crossover frequency at 3400Hz. On the other hand, the Foundation B2 features a 1" Gen2 Obsidian Folded Motion Ribbon Tweeter and 1 x 6-1/2" Aluminum Woofer with a Crossover frequency at 3800Hz.
Frequency Response
Foundation B1 has a frequency range of 48-23k Hz whereas Foundation B2 has a frequency range of 42-23k Hz. With a minimum frequency of 42Hz, the Foundation B2 can go significantly deeper on the low side and provide stronger bass compared to the Foundation B1'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 Bookshelf class in our database.
Low Frequency
Bookshelf 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
Foundation B1 and Foundation B2 have the same Impedance of 5 ohms but where they differ is the sensitivity levels. Foundation B1 sensitivity is rated at 89 dB and the Foundation B2's is at 90 dB. This 1 dB difference makes the MartinLogan Foundation B2 a more sensitive speaker compared to MartinLogan Foundation B1, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf 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.
Foundation B1 and Foundation B2 have the same power range of up to 100 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.
MartinLogan Foundation B1
MartinLogan Foundation B2
Input Type and Bi-Amping / Bi-Wiring
Foundation B1 features Binding post type posts and Foundation B2 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
MartinLogan Foundation B1's Binding post terminals
MartinLogan Foundation B2's Binding post terminals
Cabinet Type and Port Position
Both Foundation B1 and Foundation B2 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.
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 Foundation B1's and MartinLogan Foundation B2's external dimensions. MartinLogan Foundation B1 has external dimensions of 347.0 x 185.0 x 242.0mm (13-5/8inch x 7-1/4inch x 9-1/2inch) whereas MartinLogan Foundation B2 has external dimensions of 381.0 x 197.0 x 242.0mm (15inch x 7-3/4inch x 9-1/2inch).
Below you can see the front view size comparison of MartinLogan Foundation B1 and MartinLogan Foundation B2 in scale.
Comparison image of MartinLogan Foundation B1 and MartinLogan Foundation B2 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 Foundation B1 is approximately 447.7cm2 / 69.4inch2 and base area of the MartinLogan Foundation B2 is approximately 476.7cm2 / 73.9inch2. The Foundation B1 requires 6% less surface area than the Foundation B2 which gives it a small advantage on placement in tight spaces.
Here is another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
Size Comparison image of MartinLogan Foundation B1 and MartinLogan Foundation B2 on a Media Console
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 Foundation B1 weighs 5.23kg / 11.5lbs and the MartinLogan Foundation B2 weighs 5.23kg / 11.5lbs.
Here is a comparison of how Foundation B1 and Foundation B2's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
MartinLogan Foundation B1
MartinLogan Foundation B2
 Base Surface Area |
447cm2
vs
476cm2
|
Takes less floor space |
 Price per pair* |
599USD
vs
799USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
90 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6-1/2 inches
vs
5-1/2 inches
|
Larger woofer |
|
Low Frequency Response |
42 Hz
vs
48 Hz
|
Generates deeper bass |
| General |
MartinLogan Foundation B1 |
MartinLogan Foundation B2 |
| Brand |
MartinLogan |
MartinLogan |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
up to 100 watts |
up to 100 watts |
| Sensitivity |
89 dB |
90 dB |
| Impedance |
5 ohms |
5 ohms |
| Frequency Response |
48-23k Hz |
42-23k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5-1/2" |
6-1/2" |
| Woofer Composition |
Aluminum |
Aluminum |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Folded Motion Ribbon |
Folded Motion Ribbon |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
3400Hz |
3800Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
381.0mm (15") |
381.0mm (15") |
| Width |
185.0mm (7.3") |
197.0mm (7.8") |
| Depth |
242.0mm (9.5") |
242.0mm (9.5") |
| Weight |
5.23kg (11.5lbs) |
5.23kg (11.5lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Walnut,Black,Satin White |
Walnut,Black,Satin White |
| Mounting Bracket |
|
|
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 years |
5 years |
| Labor Warranty |
5 years |
5 years |
Siblings in MartinLogan's Foundation series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass |
B |
MartinLogan Foundation B2 digs deeper - 42Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs |
evenly matched |
Similar sensitivity (89dB vs 90dB) - both want much the same power. |
| Headroom |
evenly matched |
Similar power handling (100W vs 100W). |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Price |
A |
MartinLogan Foundation B1 is cheaper - $599 against $799, about 25% less. |
A MartinLogan Foundation B1
B MartinLogan Foundation B2
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 Foundation B2 is ahead, but only on 1 of the measured areas, and it costs about 25% more. That is a lot of money for a narrow margin on paper - MartinLogan Foundation B1 looks like the sensible buy unless something else about the MartinLogan Foundation B2 appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 48Hz anyway, which makes the cheaper MartinLogan Foundation B1 much easier to justify. Think about the whole system, not just the speakers: the roughly $200 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.