In this review, we will be comparing AE520 and Concord, two Passive Floor-standing speakers from Acoustic Energy and KLH.
Let's have a brief look at the main features
of AE520 and KLH Concord first before getting into our more
detailed comparison.
| Key Specs | AE520 | KLH Concord |
|---|
| Design | 3-way | 2-way |
|---|
| Tweeter | 1" dome with waveguide | 1" |
|---|
| Midrange | 5.2" | — |
|---|
| Woofer | 4 x 5" carbon fibre cone | 2 x 6.5" Kevlar |
|---|
| Frequency response | 30Hz - 28kHz | 28-23k Hz |
|---|
| Sensitivity | 90 dB | 94 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | up to 300 watts | up to 225 watts |
|---|
| Weight | 30.00kg / 66lbs | 20.45kg / 45lbs |
|---|
| Dimensions (H x W x D) | 44.5" x 7.3" x 12.6"
1130.0 x 185.0 x 320.0mm | 40-3/8" x 8-5/16" x 14-15/16"
1026.0 x 212.0 x 380.0mm |
|---|
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
One of the fundamental differences between these two speakers is that AE520 is a 3-way design whereas the Concord is a 2-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.
AE520KLH Concord
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
AE520 |
KLH Concord |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
1 x 5.2-inch |
- |
|
Woofer
|
4 x 5-inch
|
2 x 6.5-inch
|
AE520 features a 1" carbon fibre dome with waveguide Tweeter, a 5.2" Midrange and 4 x 5" carbon fibre cone Woofer with a Crossover frequency at 373Hz and 2.8kHz. On the other hand, the Concord features a 1" anodized aluminum Tweeter and 2 x 6.5" Kevlar Woofer.
Frequency Response
AE520 has a frequency range of 30Hz - 28kHz whereas Concord has a frequency range of 28-23k Hz. With a minimum frequency of 28Hz, the Concord can go slightly deeper then the AE520's min frequency of 30Hz.
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
AE520 is a 6 ohms speaker compared to the Concord which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. AE520 sensitivity is rated at 90 dB and the Concord's is rated at 94 dB. This 4 dB difference makes the KLH Concord a more sensitive speaker compared to AE520, 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.
AE520 can handle a max power of 300 watts RMS, whereas Concord has a max power handling value of watts RMS, 300 watts less than the AE520.
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 AE520's and KLH Concord's external dimensions. AE520 has external dimensions of 1130.0 x 185.0 x 320.0mm (44.5 x 7.3 x 12.6inch) whereas KLH Concord has external dimensions of 1026.0 x 212.0 x 380.0mm (40-3/8 x 8-5/16 x 14-15/16inch).
AE520 is 27mm narrower and 60mm less deeper than KLH Concord but it is also 104mm taller.
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 AE520 is approximately 592.0cm2 / 91.8inch2 and base area of the KLH Concord is approximately 805.6cm2 / 124.9inch2. The AE520 requires 27% less surface area than the Concord 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 AE520 weighs 30.00kg / 66lbs and the KLH Concord weighs 20.45kg / 45lbs. This makes the AE520 47% heavier than the Concord.
Here is a comparison of how AE520 and Concord'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 KLH Concord?
Here are the items that come with the Concord:
- Floorstanding loudspeaker
- Grille
- 4 Spike feet (w/ locking nut attached)
- 4 Protective discs
- 4 Rubber feet
- Port plug
- Manual
- ATTENTION! note
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Number of Woofers |
4
vs
2
|
More woofers |
 High Frequency Response |
28k Hz
vs
23k Hz
|
Generates higher frequency |
 Base Surface Area |
592cm2
vs
805cm2
|
Takes less floor space |
 Sensitivity |
94 dB
vs
90 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
|
Woofer Size |
6.5 inches
vs
5 inches
|
Larger woofer |
|
Low Frequency Response |
28 Hz
vs
30 Hz
|
Generates deeper bass |
 Height |
1026mm
vs
1130mm
|
Easier to fit in smaller spaces |
 Price per pair* |
1000USD
vs
4999USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Acoustic Energy AE520 |
KLH Concord |
| Brand |
Acoustic Energy |
KLH |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 300 watts |
up to 225 watts |
| Sensitivity |
90 dB |
94 dB |
| Impedance |
6 ohms |
8 ohms |
| Frequency Response |
30Hz - 28kHz |
28-23k Hz |
Drivers |
|
|
| Woofer Quantity |
4 |
2 |
| Woofer Size |
5" |
6.5" |
| Woofer Composition |
carbon fibre cone |
Kevlar |
| Woofer Surround Material |
n/a |
Butyl Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
dome with waveguide |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5.2" |
No |
| Crossover Frequency |
373Hz and 2.8kHz |
n/a |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
1130.0mm (44.5") |
1026.0mm (40.4") |
| Width |
185.0mm (7.3") |
212.0mm (8.3") |
| Depth |
320.0mm (12.6") |
380.0mm (15") |
| Weight |
30.00kg (66lbs) |
20.45kg (45lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Resonance Suppression Composite (RSC) |
MDF/Wood-grain vinyl |
| Available Colors |
Piano Gloss Black, Piano Gloss White, American Walnut wood veneer |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
|
10 Years |
| Labor Warranty |
|
10 Years |
These sit in different price classes - AE520 costs roughly 5x what KLH Concord does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass |
evenly matched |
Much the same reach (30Hz vs 28Hz). |
| Amplifier needs |
B |
KLH Concord is more sensitive (94dB vs 90dB), so it goes louder on the same amplifier. |
| Amplifier match |
B |
KLH Concord is the easier load at 8 ohms. |
| Size |
depends |
Similar cabinet size - neither is easier to fit. |
| Price |
B |
KLH Concord is cheaper - $1,000 against $4,999, about 80% less; arguably a different class. |
A AE520
B KLH Concord
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?
KLH Concord is the easier recommendation: it leads on most of the measured areas and costs less. Take AE520 if its size, looks or fit in your room suit you better. If your amplifier is modest, vintage or valve-based, KLH Concord is the safer partner - the other will want more current or more watts to sound its best. Think about the whole system, not just the speakers: the roughly $3,999 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.