In this review, we will be comparing Forte IV and Heresy III, two Passive Floor-standing speakers by Klipsch.
Let's have a brief look at the main features
of Klipsch Forte IV and Klipsch Heresy III first before getting into our more
detailed comparison.
| Key Specs | Klipsch Forte IV | Klipsch Heresy III |
|---|
| Brand | Klipsch
United States · founded 1946 | Klipsch
United States · founded 1946 |
|---|
| Design | 3-way | 3-way |
|---|
| Tweeter | 1" horn-loaded | 1" Tractrix horn |
|---|
| Midrange | 1.75" | 1.75" |
|---|
| Woofer | 12" Fibercomposite | 12" Fiber-composite |
|---|
| Frequency response | 38-20k Hz | 58-20k Hz |
|---|
| Sensitivity | 99 dB | 99 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | up to 100 watts | 100 watts |
|---|
| Weight | 32.73kg / 72lbs | 20.00kg / 44lbs |
|---|
| Dimensions (H x W x D) | 35-3/4" x 16-5/8" x 13"
909.0 x 423.0 x 331.0mm | 23-7/8" x 15-1/2" x 13-7/16"
607.0 x 394.0 x 342.0mm |
|---|
Forte IV and Heresy III are members of Klipsch's Heritage series of speakers. Below you can find the loudspeakers from this series.
Klipsch Heritage Series
History
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Forte IV and Heresy III are 3-way speakers.
Klipsch Forte IVKlipsch Heresy III
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 Forte IV |
Klipsch Heresy III |
|
Driver Setup
|
3-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
1 x 1.75-inch |
1 x 1.75-inch |
|
Woofer
|
1 x 12-inch
|
1 x 12-inch
|
Forte IV features a 1" titanium-diaphragm compression horn-loaded Tweeter, a 1.75" Midrange and 1 x 12" Fibercomposite Woofer. On the other hand, the Heresy III features a 1" titanium-diaphragm compression Tractrix horn Tweeter, a 1.75" Midrange and 1 x 12" Fiber-composite Woofer.
Frequency Response
Forte IV has a frequency range of 38-20k Hz whereas Heresy III has a frequency range of 58-20k Hz. With a minimum frequency of 38Hz, the Forte IV can go significantly deeper on the low side and provide stronger bass compared to the Heresy III's min frequency of 58Hz.
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
Forte IV and Heresy III have the same Impedance of 8 ohms and their sensitivity is also same at 99 dB.
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.
Both handle the same maximum of 100 watts RMS, though Forte IV is rated up to 100 watts and Heresy III 100 watts.
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
Both Forte IV and Heresy III features dual binding post speaker terminals for bi-amping or bi-wiring.
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 Forte IV's and Klipsch Heresy III's external dimensions. Klipsch Forte IV has external dimensions of 909.0 x 423.0 x 331.0mm (35-3/4 x 16-5/8 x 13inch) whereas Klipsch Heresy III has external dimensions of 607.0 x 394.0 x 342.0mm (23-7/8 x 15-1/2 x 13-7/16inch).
Klipsch Heresy III is 29mm narrower and 302mm shorter than Klipsch Forte IV but it is also 11mm deeper.
Below you can see the front view size comparison of Klipsch Forte IV and Klipsch Heresy III in scale.
Comparison image of Klipsch Forte IV and Klipsch Heresy III 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 Forte IV is approximately 1400.1cm2 / 217.0inch2 and base area of the Klipsch Heresy III is approximately 1347.5cm2 / 208.9inch2. The Forte IV requires 4% more surface area than the Heresy III 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 Forte IV weighs 32.73kg / 72lbs and the Klipsch Heresy III weighs 20.00kg / 44lbs. This makes the Forte IV 64% heavier than the Heresy III.
Here is a comparison of how Forte IV and Heresy III'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 Forte IV?
Here are the items that are included inside the box of Forte IV:
- 2 Floorstanding loudspeakers
- 2 Grilles
- 8 Self-adhesive rubber feet
- Owners Manual
- Congratulations letter
- Klipsch brochure
What's in the Box of Klipsch Heresy III?
Here are the items that come with the Heresy III:
- Floor-standing loudspeaker
- Detachable grille (installed)
- Base riser (installed)
- 4 Self-adhesive rubber feet
- Owners Manual
- Congratulations letter
- Klipsch brochure
 Low Frequency Response |
38 Hz
vs
58 Hz
|
Generates deeper bass |
 Passive Radiator |
rear-firing 15-inch
vs
None
|
Increases the bass performance |
 Height |
607mm
vs
909mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1347cm2
vs
1400cm2
|
Takes less floor space |
 Price per pair* |
2346USD
vs
4998USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Klipsch Heritage Forte IV |
Klipsch Capitol Heresy III |
| Brand |
Klipsch |
Klipsch |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 100 watts |
100 watts |
| Sensitivity |
99 dB |
99 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
38-20k Hz |
58-20k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
12" |
| Woofer Composition |
Fibercomposite |
Fiber-composite |
| Woofer Surround Material |
Rubber |
Treated cloth |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
horn-loaded |
Tractrix horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
1.75" |
1.75" |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
909.0mm (35.8") |
607.0mm (23.9") |
| Width |
423.0mm (16.7") |
394.0mm (15.5") |
| Depth |
331.0mm (13") |
342.0mm (13.5") |
| Weight |
32.73kg (72lbs) |
20.00kg (44lbs) |
| Enclosure |
Passive Radiator |
Acoustic Suspension |
| Finish |
MDF/Wood veneer |
MDF/Wood veneer |
| Available Colors |
Black |
Blonde Cherry |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
10 Years |
5 Years |
| Labor Warranty |
10 Years |
5 Years |
Siblings in Klipsch's Heritage series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | A | Klipsch Forte IV digs deeper - 38Hz against 58Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (99dB vs 99dB) - both want much the same power. |
| Headroom | evenly matched | Similar power handling (100W vs 100W). |
| Size | depends | Klipsch Heresy III is easier to place; Klipsch Forte IV is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Passive Radiator vs Sealed. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Expandability | depends | Klipsch Forte IV: bi-amping; Klipsch Heresy III: bi-amping. |
| Price | B | Klipsch Heresy III is cheaper - $2,346 against $4,998, about 53% less; arguably a different class. |
A Klipsch Forte IV B Klipsch Heresy III
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?
Klipsch Forte IV is ahead, but only on 1 of the measured areas, and it costs about 113% more. That is a lot of money for a narrow margin on paper - Klipsch Heresy III looks like the sensible buy unless something else about the Klipsch Forte IV appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 58Hz anyway, which makes the cheaper Klipsch Heresy III much easier to justify. In a large or open-plan room, Klipsch Forte IV has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Klipsch Heresy III 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.