In this review, we will be comparing ES55 and Concord, two Passive Floor-standing speakers from Polk Audio and KLH.
Let's have a brief look at the main features
of Polk ES55 and KLH Concord first before getting into our more
detailed comparison.
| Key Specs | Polk ES55 | KLH Concord |
|---|
| Brand | Polk Audio
United States · founded 1972 | KLH
United States · founded 1957 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" |
|---|
| Woofer | 3 x 6.5" Mica-reinforced polypropylene | 2 x 6.5" Kevlar |
|---|
| Frequency response | 34-40k Hz | 28-23k Hz |
|---|
| Sensitivity | 89 dB | 94 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 40-200 watts | up to 225 watts |
|---|
| Weight | 20.00kg / 44lbs | 20.45kg / 45lbs |
|---|
| Dimensions (H x W x D) | 41-9/16" x 8-1/2" x 12-3/8"
1056.0 x 216.0 x 315.0mm | 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.
Drivers
Both ES55 and Concord are 2-way speakers.
Polk ES55KLH Concord
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Polk ES55 |
KLH Concord |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
3 x 6.5-inch
|
2 x 6.5-inch
|
ES55 features a 1" Terylene High-Res Soft-Dome Tweeter and 3 x 6.5" Mica-reinforced polypropylene Woofer with a Crossover frequency at 2500Hz. On the other hand, the Concord features a 1" anodized aluminum Tweeter and 2 x 6.5" Kevlar Woofer.
Frequency Response
ES55 has a frequency range of 34-40k Hz whereas Concord has a frequency range of 28-23k Hz. With a minimum frequency of 28Hz, the Concord can go significantly deeper on the low side and provide stronger bass compared to the ES55's min frequency of 34Hz.
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
ES55 and Concord have the same Impedance of 8 ohms but where they differ is the sensitivity levels. ES55 sensitivity is rated at 89 dB and the Concord's is at 94 dB. This 5 dB difference makes the KLH Concord a more sensitive speaker compared to Polk ES55, 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.
Concord can handle a max power of 225 watts RMS, whereas ES55 has a max power handling value of 200 watts RMS, 25 watts less than the Concord.
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.
Input Type and Bi-Amping / Bi-Wiring
ES55 features 5-Way post posts which make bi-amping or bi-wiring possible. Concord has a 5-Way post which doesn't feature bi-amping/bi-wiring.
KLH Concord's 5-Way post terminals
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 Polk ES55's and KLH Concord's external dimensions. Polk ES55 has external dimensions of 1056.0 x 216.0 x 315.0mm (41-9/16 x 8-1/2 x 12-3/8inch) 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).
KLH Concord is 4mm narrower and 30mm shorter than Polk ES55 but it is also 65mm deeper.
Below you can see the front view size comparison of Polk ES55 and KLH Concord in scale.
Comparison image of Polk ES55 and KLH Concord 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 Polk ES55 is approximately 680.4cm2 / 105.5inch2 and base area of the KLH Concord is approximately 805.6cm2 / 124.9inch2. The ES55 requires 16% 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 Polk ES55 weighs 20.00kg / 44lbs and the KLH Concord weighs 20.45kg / 45lbs. This makes the Concord 2% heavier than the ES55.
Here is a comparison of how ES55 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 Polk ES55?
Here are the items that are included inside the box of ES55:
- Floorstanding loudspeaker
- Grille (attached)
- 4 Feet (pre-installed)
- Owners Manual
- Online Product Registration
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
 Number of Woofers |
3
vs
2
|
More woofers |
 High Frequency Response |
40k Hz
vs
23k Hz
|
Generates higher frequency |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Base Surface Area |
680cm2
vs
805cm2
|
Takes less floor space |
 Price per pair* |
898USD
vs
1000USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
225 watts
vs
200 watts
|
Handle more power from your amplifier |
 Sensitivity |
94 dB
vs
89 dB
|
Play louder with same amount of amplification power |
|
Low Frequency Response |
28 Hz
vs
34 Hz
|
Generates deeper bass |
 Height |
1026mm
vs
1056mm
|
Easier to fit in smaller spaces |
| General |
Polk Audio Signature Elite ES55 |
KLH Concord |
| Brand |
Polk Audio |
KLH |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
40-200 watts |
up to 225 watts |
| Sensitivity |
89 dB |
94 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
34-40k Hz |
28-23k Hz |
Drivers |
|
|
| Woofer Quantity |
3 |
2 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Mica-reinforced polypropylene |
Kevlar |
| Woofer Surround Material |
Butyl rubber |
Butyl Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2500Hz |
n/a |
| Firing Direction |
bottom |
n/a |
Physical Specs |
|
|
| Height |
1056.0mm (41.6") |
1026.0mm (40.4") |
| Width |
216.0mm (8.5") |
212.0mm (8.3") |
| Depth |
315.0mm (12.4") |
380.0mm (15") |
| Weight |
20.00kg (44lbs) |
20.45kg (45lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF, Wood-grain vinyl |
MDF/Wood-grain vinyl |
| Available Colors |
Black |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
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 | KLH Concord digs deeper - 28Hz against 34Hz. A subwoofer would even that out. |
| Amplifier needs | B | KLH Concord is more sensitive (94dB vs 89dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (200W vs 225W). |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | A | Polk ES55: bi-amping. |
| Price | A | Polk ES55 is cheaper - $898 against $1,000, about 10% less. |
A Polk ES55 B KLH Concord
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: KLH Concord measures better, Polk ES55 costs about about 11% 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 34Hz anyway, which makes the cheaper Polk ES55 much easier to justify. 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.
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.