In this review, we will be comparing AE509 and Kendall, two Passive Floor-standing speakers from Acoustic Energy and KLH.
Let's have a brief look at the main features
of AE509 and KLH Kendall first before getting into our more
detailed comparison.
| Key Specs | AE509 | KLH Kendall |
|---|
| Brand | Acoustic Energy
United Kingdom · founded 1987 | KLH
United States · founded 1957 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 1" dome with waveguide | 1" |
|---|
| Midrange | — | 5.25" |
|---|
| Woofer | 2 x 5" carbon fibre cone | 2 x 6.5" Woven Kevlar |
|---|
| Frequency response | 32Hz - 28kHz | 25-23k Hz |
|---|
| Sensitivity | 89 dB | 96 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | up to 175 watts | up to 250 watts |
|---|
| Weight | 22.00kg / 48.4lbs | 22.14kg / 48.7lbs |
|---|
| Dimensions (H x W x D) | 39.4" x 7.3" x 10.6"
1000.0 x 185.0 x 270.0mm | 40-3/16" x 8-5/16" x 14-15/16"
1021.0 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.
Drivers
One of the fundamental differences between these two speakers is that AE509 is a 2-way design whereas the Kendall is a 3-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.
AE509KLH Kendall
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
AE509 |
KLH Kendall |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 5.25-inch |
|
Woofer
|
2 x 5-inch
|
2 x 6.5-inch
|
AE509 features a 1" carbon fibre dome with waveguide Tweeter and 2 x 5" carbon fibre cone Woofer with a Crossover frequency at 2800Hz. On the other hand, the Kendall features a 1" anodized aluminum Tweeter, a 5.25" Midrange and 2 x 6.5" Woven Kevlar Woofer.
Frequency Response
AE509 has a frequency range of 32Hz - 28kHz whereas Kendall has a frequency range of 25-23k Hz. With a minimum frequency of 25Hz, the Kendall can go significantly deeper on the low side and provide stronger bass compared to the AE509's min frequency of 32Hz.
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
AE509 is a 6 ohms speaker compared to the Kendall which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. AE509 sensitivity is rated at 89 dB and the Kendall's is rated at 96 dB. This 7 dB difference makes the KLH Kendall a more sensitive speaker compared to AE509, 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.
Kendall can handle a max power of 250 watts RMS, whereas AE509 has a max power handling value of 175 watts RMS, 75 watts less than the Kendall.
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 AE509's and KLH Kendall's external dimensions. AE509 has external dimensions of 1000.0 x 185.0 x 270.0mm (39.4 x 7.3 x 10.6inch) whereas KLH Kendall has external dimensions of 1021.0 x 212.0 x 380.0mm (40-3/16 x 8-5/16 x 14-15/16inch).
KLH Kendall is clearly the larger of the two speakers. Its body is 27mm wider, 21mm taller and 110mm deeper than AE509.
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 AE509 is approximately 499.5cm2 / 77.4inch2 and base area of the KLH Kendall is approximately 805.6cm2 / 124.9inch2. The AE509 requires 38% less surface area than the Kendall 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 AE509 weighs 22.00kg / 48.4lbs and the KLH Kendall weighs 22.14kg / 48.7lbs. This makes the Kendall 1% heavier than the AE509.
Here is a comparison of how AE509 and Kendall'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 Kendall?
Here are the items that come with the Kendall:
- Floorstanding loudspeaker
- Grille
- Foam port
- 4 Rubber feet
- 4 Spike feet (with nuts)
- 4 Protective discs
- Manual
 High Frequency Response |
28k Hz
vs
23k Hz
|
Generates higher frequency |
 Height |
1000mm
vs
1021mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
499cm2
vs
805cm2
|
Takes less floor space |
 Max Input Power |
250 watts
vs
175 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
96 dB
vs
89 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 |
25 Hz
vs
32 Hz
|
Generates deeper bass |
 Price per pair* |
1500USD
vs
3499USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Acoustic Energy AE509 |
KLH Kendall |
| Brand |
Acoustic Energy |
KLH |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 175 watts |
up to 250 watts |
| Sensitivity |
89 dB |
96 dB |
| Impedance |
6 ohms |
8 ohms |
| Frequency Response |
32Hz - 28kHz |
25-23k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5" |
6.5" |
| Woofer Composition |
carbon fibre cone |
Woven 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 |
No |
5.25" |
| Crossover Frequency |
2800Hz |
n/a |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
1000.0mm (39.4") |
1021.0mm (40.2") |
| Width |
185.0mm (7.3") |
212.0mm (8.3") |
| Depth |
270.0mm (10.6") |
380.0mm (15") |
| Weight |
22.00kg (48.4lbs) |
22.14kg (48.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Resonance Suppression Composite (RSC) |
MDF/Wood Veneer |
| 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 |
Yes |
Other |
|
|
| Parts Warranty |
|
10 Years |
| Labor Warranty |
|
10 Years |
These sit in different price classes - AE509 costs roughly 2.3x what KLH Kendall 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 | B | KLH Kendall digs deeper - 25Hz against 32Hz. A subwoofer would even that out. |
| Amplifier needs | B | KLH Kendall is more sensitive (96dB vs 89dB), so it goes louder on the same amplifier. |
| Amplifier match | B | KLH Kendall is the easier load at 8 ohms. |
| Headroom | B | KLH Kendall takes more power (250W vs 175W) - more in hand in a big room. |
| Size | depends | AE509 is easier to place; KLH Kendall is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | B | KLH Kendall: bi-amping. |
| Price | B | KLH Kendall is cheaper - $1,500 against $3,499, about 57% less; arguably a different class. |
A AE509 B KLH Kendall
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?
KLH Kendall is the easier recommendation: it leads on most of the measured areas and costs less. Take AE509 if its size, looks or fit in your room suit you better. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 32Hz anyway, so judge these on the other rows instead. In a large or open-plan room, KLH Kendall has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, AE509 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.