In this review, we will be comparing AE500 and S400 MKII, two Passive Bookshelf speakers from Acoustic Energy and Buchardt.
Let's have a brief look at the main features
of AE500 and Buchardt S400 MKII first before getting into our more
detailed comparison.
| Key Specs | AE500 | Buchardt S400 MKII |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" dome with waveguide | 0.74" aluminum waveguide |
|---|
| Woofer | 5" carbon fibre cone | 6" paper |
|---|
| Frequency response | 45Hz - 28kHz | 33-40k HZ |
|---|
| Sensitivity | 87 dB | 88 dB |
|---|
| Impedance | 6 ohms | 4 ohms |
|---|
| Power range | up to 120 watts | 40-200 watts |
|---|
| Weight | 8.00kg / 17.6lbs | 7.50kg / 16.5lbs |
|---|
| Dimensions (H x W x D) | 12.2" x 7.3" x 10.2"
310.0 x 185.0 x 260.0mm | 14.4" x 7" x 11"
365.0 x 180.0 x 280.0mm |
|---|
What size room are the AE500 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* |
AE500 |
Buchardt S400 MKII |
| Near-field |
Average |
Poor |
| Small Room |
Good |
Average |
| Mid-size Room |
Average |
Good |
| Large Room |
Poor |
Average |
| Very Large Room |
Bad |
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.
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Drivers
Both AE500 and S400 MKII are 2-way speakers.
AE500Buchardt 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 |
AE500 |
Buchardt S400 MKII |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
0.74-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
1 x 6-inch
|
AE500 features a 1" carbon fibre dome with waveguide Tweeter and 1 x 5" carbon fibre cone Woofer with a Crossover frequency at 2800Hz. 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
AE500 has a frequency range of 45Hz - 28kHz 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 AE500's min frequency of 45Hz.
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
AE500 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. AE500 sensitivity is rated at 87 dB and the S400 MKII's is rated at 88 dB. This 1 dB difference makes the Buchardt S400 MKII a more sensitive speaker compared to AE500, 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.
S400 MKII can handle a max power of 200 watts RMS, whereas AE500 has a max power handling value of 100 watts RMS, 100 watts less than the S400 MKII.
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 AE500's and Buchardt S400 MKII's external dimensions. AE500 has external dimensions of 310.0 x 185.0 x 260.0mm (12.2 x 7.3 x 10.2inch) whereas Buchardt S400 MKII has external dimensions of 365.0 x 180.0 x 280.0mm (14.4 x 7 x 11inch).
AE500 is 55mm shorter and 20mm less deeper than Buchardt S400 MKII but it is also 5mm wider.
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 AE500 is approximately 481.0cm2 / 74.6inch2 and base area of the Buchardt S400 MKII is approximately 504.0cm2 / 78.1inch2. The AE500 requires 5% less surface area than the S400 MKII 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 AE500 weighs 8.00kg / 17.6lbs and the Buchardt S400 MKII weighs 7.50kg / 16.5lbs. This makes the AE500 7% heavier than the S400 MKII.
Here is a comparison of how AE500 and S400 MKII's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
 Nominal Impedance |
6 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Height |
310mm
vs
365mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
481cm2
vs
504cm2
|
Takes less floor space |
 Price per pair* |
1499USD
vs
2200USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
200 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
88 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6 inches
vs
5 inches
|
Larger woofer |
|
Low Frequency Response |
33 Hz
vs
45 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
28k Hz
|
Generates higher frequency |
 Passive Radiator |
one 5x8-inch
vs
None
|
Increases the bass performance |
| General |
Acoustic Energy AE500 |
Buchardt S400 MKII |
| Brand |
Acoustic Energy |
Buchardt |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
up to 120 watts |
40-200 watts |
| Sensitivity |
87 dB |
88 dB |
| Impedance |
6 ohms |
4 ohms |
| Frequency Response |
45Hz - 28kHz |
33-40k HZ |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5" |
6" |
| Woofer Composition |
carbon fibre cone |
paper |
| Tweeter Size |
1" |
0.74" |
| Tweeter Type |
dome with waveguide |
aluminum waveguide |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2800Hz |
1800Hz |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
310.0mm (12.2") |
365.0mm (14.4") |
| Width |
185.0mm (7.3") |
180.0mm (7.1") |
| Depth |
260.0mm (10.2") |
280.0mm (11") |
| Weight |
8.00kg (17.6lbs) |
7.50kg (16.5lbs) |
| Enclosure |
Bass Reflex |
Passive Radiator |
| Finish |
Resonance Suppression Composite (RSC) |
n/a |
| Available Colors |
Piano Gloss Black, Piano Gloss White, American Walnut wood veneer |
Black, White, Walnut, Rosewood, Light Oak |
| Mounting Bracket |
|
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
10 years |
| Labor Warranty |
|
10 years |
A generation apart: Buchardt S400 MKII is the newer design, against a 2017 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass |
B |
Buchardt S400 MKII digs deeper - 33Hz against 45Hz. |
| Amplifier needs |
evenly matched |
Similar sensitivity (87dB vs 88dB) - both want much the same power. |
| Amplifier match |
A |
AE500 is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom |
B |
Buchardt S400 MKII takes more power (200W vs 100W) - more in hand in a big room. |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Cabinet |
depends |
Ported vs Passive Radiator. |
| Expandability |
depends |
Neither adds bi-amping, a sub output or height drivers. Buchardt S400 MKII sits in a wider range (6 models), so a matched surround system is easier later. |
| Price |
A |
AE500 is cheaper - $1,499 against $2,200, about 32% less. |
A AE500
B Buchardt S400 MKII
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?
Buchardt S400 MKII is ahead, but only on 1 of the measured areas, and it costs about 32% more. That is a lot of money for a narrow margin on paper - AE500 looks like the sensible buy unless something else about the Buchardt S400 MKII appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 45Hz anyway, which makes the cheaper AE500 much easier to justify. Match it to your room: we rate AE500 the better fit for near-field listening and a small room, and Buchardt S400 MKII for a mid-size room and a large 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.