In this review, we will be comparing Passif 50 and S400 MKII, two Passive Bookshelf speakers from PSB and Buchardt.
Let's have a brief look at the main features
of PSB Passif 50 and Buchardt S400 MKII first before getting into our more
detailed comparison.
| Key Specs | PSB Passif 50 | Buchardt S400 MKII |
|---|
| Brand | PSB
Canada · founded 1972 | Buchardt
Denmark · founded 2014 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Dome | 0.74" aluminum waveguide |
|---|
| Woofer | 6.5" cast aluminum basket, paper cone | 6" paper |
|---|
| Frequency response | 50-20k Hz | 33-40k Hz |
|---|
| Sensitivity | 87 dB | 88 dB |
|---|
| Impedance | 6 ohms | 4 ohms |
|---|
| Power range | 30-200 Watts watts | 40-200 watts |
|---|
| Weight | 13.70kg / 30.1lbs | 7.50kg / 16.5lbs |
|---|
| Dimensions (H x W x D) | 26" x 11" x 10"
660 × 280 × 254mm | 14.4" x 7" x 11"
365.0 x 180.0 x 280.0mm |
|---|
What size room are the PSB Passif 50 and Buchardt S400 MKII 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* |
PSB Passif 50 |
Buchardt S400 MKII |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
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 Passif 50 and S400 MKII are 2-way speakers.
PSB Passif 50Buchardt S400 MKII
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
PSB Passif 50 |
Buchardt S400 MKII |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
0.74-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 6-inch
|
Passif 50 features a 1" titanium dome with ferrofluid and neodymium magnet Dome Tweeter and 1 x 6.5" cast aluminum basket, paper cone Woofer with a Crossover frequency at 1800Hz. On the other hand, the S400 MKII features a 0.74" fine weave soft fabric textile aluminum waveguide Tweeter and 1 x 6" paper Woofer with a Crossover frequency at 1800Hz.
Frequency Response
Passif 50 has a frequency range of 50-20k Hz whereas S400 MKII has a frequency range of 33-40k Hz. With a minimum frequency of 33Hz, the S400 MKII can go significantly deeper on the low side and provide stronger bass compared to the Passif 50's min frequency of 50Hz.
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
Passif 50 is a 6 ohms speaker compared to the S400 MKII which has a nominal impedance of 4 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 S400 MKII can provide this impedance level.
These two speakers also have different sensitivity levels. Passif 50 sensitivity is rated at 87 dB and the S400 MKII's is rated at 88 dB. This 1 dB difference makes the PSB Passif 50 a more sensitive speaker compared to Buchardt S400 MKII, 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.
Both handle the same maximum of 200 watts RMS, though Passif 50 is rated 30-200 Watts watts and S400 MKII 40-200 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.
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 PSB Passif 50's and Buchardt S400 MKII's external dimensions. PSB Passif 50 has external dimensions of 660 × 280 × 254mm (26 x 11 x 10-inch) whereas Buchardt S400 MKII has external dimensions of 365.0 x 180.0 x 280.0mm (14.4 x 7 x 11inch).
Buchardt S400 MKII is 100mm narrower and 295mm shorter than PSB Passif 50 but it is also 26mm deeper.
Below you can see the front view size comparison of PSB Passif 50 and Buchardt S400 MKII in scale.
Comparison image of PSB Passif 50 and Buchardt S400 MKII 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 PSB Passif 50 is approximately 712.0cm2 / 110.4inch2 and base area of the Buchardt S400 MKII is approximately 504.0cm2 / 78.1inch2. The Passif 50 requires 41% more surface area than the S400 MKII 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 PSB Passif 50 weighs 13.70kg / 30.1lbs and the Buchardt S400 MKII weighs 7.50kg / 16.5lbs. This makes the Passif 50 83% heavier than the S400 MKII.
Here is a comparison of how Passif 50 and S400 MKII's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
 Sensitivity |
89 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
6 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Woofer Size |
6.5 inches
vs
6 inches
|
Larger woofer |
|
Low Frequency Response |
33 Hz
vs
50 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
20k Hz
|
Generates higher frequency |
 Height |
365mm
vs
660mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
504cm2
vs
712cm2
|
Takes less floor space |
 Price per pair* |
2200USD
vs
2499USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
PSB Passif 50 |
Buchardt S400 MKII |
| Brand |
PSB |
Buchardt |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-200 Watts watts |
40-200 watts |
| Sensitivity |
87 dB |
88 dB |
| Impedance |
6 ohms |
4 ohms |
| Impedance |
4 ohms |
n/a |
| Frequency Response |
50-20k Hz |
33-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6" |
| Woofer Composition |
cast aluminum basket, paper cone |
paper |
| Woofer Surround Material |
cast aluminum basket, paper cone |
n/a |
| Tweeter Size |
1" |
0.74" |
| Tweeter Type |
Dome |
aluminum waveguide |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1800Hz |
1800Hz |
Physical Specs |
|
|
| Height |
660.0mm (26") |
365.0mm (14.4") |
| Width |
280.0mm (11") |
180.0mm (7.1") |
| Depth |
254.0mm (10") |
280.0mm (11") |
| Weight |
13.70kg (30.1lbs) |
7.50kg (16.5lbs) |
| Enclosure |
Passive Radiator |
Passive Radiator |
| Finish |
open-grain walnut veneer |
n/a |
| Available Colors |
Open-Grain Walnut |
Black, White, Walnut, Rosewood, Light Oak |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
n/a |
Other |
|
|
| Parts Warranty |
5 Years |
10 years |
| Labor Warranty |
5 Years |
10 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 | B | Buchardt S400 MKII digs deeper - 33Hz against 50Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 88dB) - both want much the same power. |
| Amplifier match | A | PSB Passif 50 is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | evenly matched | Similar power handling (200W vs 200W). |
| Size | depends | Buchardt S400 MKII is easier to place; PSB Passif 50 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | A | PSB Passif 50: bi-amping. |
| Price | B | Buchardt S400 MKII is cheaper - $2,200 against $2,499, about 12% less. |
A PSB Passif 50 B Buchardt S400 MKII
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?
The usual trade-off: PSB Passif 50 measures better, Buchardt S400 MKII costs about about 14% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 50Hz anyway, so judge these on the other rows instead. In a large or open-plan room, PSB Passif 50 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Buchardt S400 MKII is the easier speaker to get right.
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.