In this review, we will be comparing Concord and R600, two Passive Floor-standing speakers from KLH and Polk Audio.
Let's have a brief look at the main features
of KLH Concord and Polk R600 first before getting into our more
detailed comparison.
| Key Specs | KLH Concord | Polk R600 |
|---|
| Brand | KLH
United States · founded 1957 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" | 1" Pinnacle Ring Radiator |
|---|
| Woofer | 2 x 6.5" Kevlar | 2 x 6.5" Polypropylene Turbine Cone |
|---|
| Frequency response | 28-23k Hz | 43-38k Hz |
|---|
| Sensitivity | 94 dB | 87.5 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | up to 225 watts | 25-200 watts |
|---|
| Weight | 20.45kg / 45lbs | 21.50kg / 47.3lbs |
|---|
| Dimensions (H x W x D) | 40-3/8" x 8-5/16" x 14-15/16"
1026.0 x 212.0 x 380.0mm | 41.9" x 11" x 15"
1063.8 x 280.7 x 381.6mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Concord and R600 are 2-way speakers.
KLH ConcordPolk R600
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
KLH Concord |
Polk R600 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
Concord features a 1" anodized aluminum Tweeter and 2 x 6.5" Kevlar Woofer. On the other hand, the R600 features a 1" Pinnacle Ring Radiator Tweeter and 2 x 6.5" Polypropylene Turbine Cone Woofer with a Crossover frequency at 2700Hz.
Frequency Response
Concord has a frequency range of 28-23k Hz whereas R600 has a frequency range of 43-38k Hz. With a minimum frequency of 28Hz, the Concord can go significantly deeper on the low side and provide stronger bass compared to the R600's min frequency of 43Hz.
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
Concord and R600 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Concord sensitivity is rated at 94 dB and the R600's is at 87.5 dB. This 6 dB difference makes the KLH Concord a more sensitive speaker compared to Polk R600, 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 R600 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
Concord features Post type posts and R600 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
KLH Concord's 5-Way post terminals
Polk R600's Post terminals
Polk R600 Port
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 KLH Concord's and Polk R600's external dimensions. 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) whereas Polk R600 has external dimensions of 1063.8 x 280.7 x 381.6mm (41.9 x 11 x 15inch).
Polk R600 is clearly the larger of the two speakers. Its body is 68.7mm wider, 37.8mm taller and 1.6mm deeper than KLH Concord.
Below you can see the front view size comparison of KLH Concord and Polk R600 in scale.
Comparison image of KLH Concord and Polk R600 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 KLH Concord is approximately 805.6cm2 / 124.9inch2 and base area of the Polk R600 is approximately 1071.2cm2 / 166.0inch2. The Concord requires 25% less surface area than the R600 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 KLH Concord weighs 20.45kg / 45lbs and the Polk R600 weighs 21.50kg / 47.3lbs. This makes the R600 5% heavier than the Concord.
Here is a comparison of how Concord and R600'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 are included inside the box of Concord:
- Floorstanding loudspeaker
- Grille
- 4 Spike feet (w/ locking nut attached)
- 4 Protective discs
- 4 Rubber feet
- Port plug
- Manual
- ATTENTION! note
What's in the Box of Polk R600?
Here are the items that come with the R600:
- Floorstanding loudspeaker
- 4 Outrigger feet (pre-installed)
- 4 Rubber feet (pre-installed)
- 4 Spike feet (pre-installed)
- Grille
- Hex-key
- Owner's Manual
- Online Registration
 Max Input Power |
225 watts
vs
200 watts
|
Handle more power from your amplifier |
 Sensitivity |
94 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
28 Hz
vs
43 Hz
|
Generates deeper bass |
 Height |
1026mm
vs
1063mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
805cm2
vs
1071cm2
|
Takes less floor space |
 Price per pair* |
1000USD
vs
1698USD
|
costs less (*prices may change depending on the seller, location and time) |
 High Frequency Response |
38k Hz
vs
23k Hz
|
Generates higher frequency |
| General |
KLH Concord |
Polk Audio Reserve R600 |
| Brand |
KLH |
Polk Audio |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 225 watts |
25-200 watts |
| Sensitivity |
94 dB |
87.5 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
4 ohms |
| Frequency Response |
28-23k Hz |
43-38k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Kevlar |
Polypropylene Turbine Cone |
| Woofer Surround Material |
Butyl Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
n/a |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2700Hz |
| Firing Direction |
n/a |
bottom |
Physical Specs |
|
|
| Height |
1026.0mm (40.4") |
1063.8mm (41.9") |
| Width |
212.0mm (8.3") |
280.7mm (11.1") |
| Depth |
380.0mm (15") |
381.6mm (15") |
| Weight |
20.45kg (45lbs) |
21.50kg (47.3lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
MDF/Vinyl |
| Available Colors |
Black |
Black, Walnut, White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
10 Years |
5 Years |
| Labor Warranty |
10 Years |
5 Years |
These sit in different price classes - Polk R600 costs roughly 1.7x 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 | A | KLH Concord digs deeper - 28Hz against 43Hz. |
| Amplifier needs | A | KLH Concord is more sensitive (94dB vs 88dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (225W vs 200W). |
| Size | depends | KLH Concord is easier to place; Polk R600 is bigger, which usually goes with fuller bass. Your room decides. |
| Price | A | KLH Concord is cheaper - $1,000 against $1,698, about 41% less; arguably a different class. |
A KLH Concord B Polk R600
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 Concord is the easier recommendation: it leads on most of the measured areas and costs less. Take Polk R600 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 43Hz anyway, so judge these on the other rows instead. 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.