In this review, we will be comparing Heresy IV and Concord, two Passive Floor-standing speakers from Klipsch and KLH.
Let's have a brief look at the main features
of Klipsch Heresy IV and KLH Concord first before getting into our more
detailed comparison.
| Key Specs | Klipsch Heresy IV | KLH Concord |
|---|
| Brand | Klipsch
United States · founded 1946 | KLH
United States · founded 1957 |
|---|
| Design | 3-way | 2-way |
|---|
| Tweeter | 1" horn-loaded | 1" |
|---|
| Midrange | 1.75" | — |
|---|
| Woofer | 12" Fiber-composite | 2 x 6.5" Kevlar |
|---|
| Frequency response | 48-20k Hz | 28-23k Hz |
|---|
| Sensitivity | 99 dB | 94 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | up to 100 watts | up to 225 watts |
|---|
| Weight | 20.45kg / 45lbs | 20.45kg / 45lbs |
|---|
| Dimensions (H x W x D) | 24-13/16" x 15-1/2" x 13-1/4"
631.0 x 394.0 x 337.0mm | 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 Heresy IV 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.
Klipsch Heresy IVKLH 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 |
Klipsch Heresy IV |
KLH Concord |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
1 x 1.75-inch |
- |
|
Woofer
|
1 x 12-inch
|
2 x 6.5-inch
|
Heresy IV features a 1" titanium-diaphragm compression horn-loaded Tweeter, a 1.75" Midrange and 1 x 12" Fiber-composite Woofer. On the other hand, the Concord features a 1" anodized aluminum Tweeter and 2 x 6.5" Kevlar Woofer.
Frequency Response
Heresy IV has a frequency range of 48-20k 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 Heresy IV's min frequency of 48Hz.
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
Heresy IV and Concord have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Heresy IV sensitivity is rated at 99 dB and the Concord's is at 94 dB. This 5 dB difference makes the Klipsch Heresy IV a more sensitive speaker compared to KLH Concord, 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 Heresy IV has a max power handling value of 100 watts RMS, 125 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
Heresy IV 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 Klipsch Heresy IV's and KLH Concord's external dimensions. Klipsch Heresy IV has external dimensions of 631.0 x 394.0 x 337.0mm (24-13/16 x 15-1/2 x 13-1/4inch) 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).
Klipsch Heresy IV is 395mm shorter and 43mm less deeper than KLH Concord but it is also 182mm wider.
Below you can see the front view size comparison of Klipsch Heresy IV and KLH Concord in scale.
Comparison image of Klipsch Heresy IV 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 Klipsch Heresy IV is approximately 1327.8cm2 / 205.8inch2 and base area of the KLH Concord is approximately 805.6cm2 / 124.9inch2. The Heresy IV requires 65% more surface area than the Concord which gives it a small disadvantage 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 Klipsch Heresy IV weighs 20.45kg / 45lbs and the KLH Concord weighs 20.45kg / 45lbs.
Here is a comparison of how Heresy IV 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 Klipsch Heresy IV?
Here are the items that are included inside the box of Heresy IV:
- 2 Floor-standing loudspeakers
- 2 Detachable grilles (installed)
- 2 Base risers (installed)
- 8 Self-adhesive rubber feet
- 4 Jumper-straps (installed)
- Owners Manual
- Congratulations letter
- Klipsch brochure
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 |
 Sensitivity |
99 dB
vs
94 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
12 inches
vs
6.5 inches
|
Larger woofer |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
631mm
vs
1026mm
|
Easier to fit in smaller spaces |
 Max Input Power |
225 watts
vs
100 watts
|
Handle more power from your amplifier |
|
Number of Woofers |
2
vs
1
|
More woofers |
|
Low Frequency Response |
28 Hz
vs
48 Hz
|
Generates deeper bass |
 High Frequency Response |
23k Hz
vs
20k Hz
|
Generates higher frequency |
 Base Surface Area |
805cm2
vs
1327cm2
|
Takes less floor space |
 Price per pair* |
1000USD
vs
3198USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Klipsch Heritage Heresy IV |
KLH Concord |
| Brand |
Klipsch |
KLH |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 100 watts |
up to 225 watts |
| Sensitivity |
99 dB |
94 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
48-20k Hz |
28-23k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
12" |
6.5" |
| Woofer Composition |
Fiber-composite |
Kevlar |
| Woofer Surround Material |
Treated cloth |
Butyl Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
horn-loaded |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
1.75" |
No |
Physical Specs |
|
|
| Height |
631.0mm (24.8") |
1026.0mm (40.4") |
| Width |
394.0mm (15.5") |
212.0mm (8.3") |
| Depth |
337.0mm (13.3") |
380.0mm (15") |
| Weight |
20.45kg (45lbs) |
20.45kg (45lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood veneer |
MDF/Wood-grain vinyl |
| Available Colors |
Black |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
Other |
|
|
| Parts Warranty |
10 Years |
10 Years |
| Labor Warranty |
10 Years |
10 Years |
These sit in different price classes - Klipsch Heresy IV costs roughly 3.2x 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 | B | KLH Concord digs deeper - 28Hz against 48Hz. |
| Amplifier needs | A | Klipsch Heresy IV is more sensitive (99dB vs 94dB), so it goes louder on the same amplifier. |
| Headroom | B | KLH Concord takes more power (225W vs 100W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | A | Klipsch Heresy IV: bi-amping. |
| Price | B | KLH Concord is cheaper - $1,000 against $3,198, about 69% less; arguably a different class. |
A Klipsch Heresy IV 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?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 48Hz anyway, so judge these on the other rows instead. If your amplifier is modest, vintage or valve-based, Klipsch Heresy IV 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.