In this review, we will be comparing ESL 9 and Forte IV, two Passive Floor-standing speakers from MartinLogan and Klipsch. Let's have a brief look at the main features
of MartinLogan ESL 9 and Klipsch Forte IV first before getting into our more
detailed comparison.
In the following sections, we will get into more detail in order to better understand how the MartinLogan ESL 9 and Klipsch Forte IV compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
One of the fundamental differences between these two speakers is that ESL 9 is a 2-way design whereas the Forte IV 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.
| Driver |
MartinLogan ESL 9 |
Klipsch Forte IV |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
9.2 x 44-inch
|
1-inch
|
|
Midrange
|
- |
1 x 1.75-inch |
|
Woofer
|
2 x 8-inch
|
1 x 12-inch
|
ESL 9 features a 9.2 x 44" curved electrostatic transducer Tweeter and 2 x 8" high-excursion paper cone Woofer . On the other hand, the Forte IV features a 1" titanium-diaphragm compression horn-loaded Tweeter , a 1.75" Midrange and 1 x 12" Fibercomposite Woofer .
Frequency Response
ESL 9 has a frequency range of 34-23k Hz whereas Forte IV has a frequency range of 38-20k Hz. With a minimum frequency of 34Hz, the ESL 9 can go slightly deeper then the Forte IV's min frequency of 38Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing Speakers
High Frequency
Floor-standing Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
ESL 9 is a 4 ohms speaker compared to the Forte IV which has a nominal impedance of 8 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the ESL 9 can provide this impedance level.
These two speakers also have different sensitivity levels. ESL 9 sensitivity is rated at 90 dB and the Forte IV's is rated at 99 dB. This 9 dB difference makes the Klipsch Forte IV a more sensitive speaker compared to MartinLogan ESL 9, 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. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
ESL 9 can handle a max power of 400 watts RMS from the amp the whereas Forte IV has a max power handling value of 100 watts RMS, 300 watts less than the ESL 9.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
Both ESL 9 and Forte IV features dual binding post speaker terminals for bi-amping or bi-wiring.
MartinLogan ESL 9's Binding post terminals allows Bi-amping or bi-wiring
Physical Specs
Size of a speaker can sometimes become an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare MartinLogan ESL 9's and Klipsch Forte IV's external dimensions. MartinLogan ESL 9 has external dimensions of 1520.0 x 266.0 x 647.0mm ( 59-13/16 x 10-7/16 x 25-7/16inch) whereas Klipsch Forte IV has external dimensions of 909.0 x 423.0 x 331.0mm ( 35-3/4 x 16-5/8 x 13inch) .
Klipsch Forte IV is 611mm shorter and 316mm less deeper than MartinLogan ESL 9 but it is also 157mm wider.
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 MartinLogan ESL 9 is approximately 1721.0cm2 / 266.8inch2 and base area of the Klipsch Forte IV is approximately 1400.1cm2 / 217.0inch2. The ESL 9 requires 23% more surface area than the Forte IV 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 MartinLogan ESL 9 weighs 35.45kg / 78lbs and the Klipsch Forte IV weighs 32.73kg / 72lbs. This makes the ESL 9 8% heavier than the Forte IV.
Here is a comparison of how ESL 9 and Forte IV'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 MartinLogan ESL 9?
Here are the items that are included inside the box of ESL 9:
Floorstanding hybrid electrostatic loudspeakerAC power adapter (w/ attached 10-feet DC cord)Grille4 Spike FeetUsers ManualProduct Registration Card
What's in the Box of Klipsch Forte IV?
Here are the items that come with the Forte IV:
2 Floorstanding loudspeakers2 Grilles8 Self-adhesive rubber feetOwners ManualCongratulations letterKlipsch brochure
 Max Input Power |
400 watts
vs
100 watts
|
Handle more power from your amplifier |
 Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
34 Hz
vs
38 Hz
|
Generates deeper bass |
 High Frequency Response |
23k Hz
vs
20k Hz
|
Generates higher frequency |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
99 dB
vs
90 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
| Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
 Passive Radiator |
rear-firing 15-inch
vs
None
|
Increases the bass performance |
 Height |
909mm
vs
1520mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1400cm2 (423x331mm)
vs
1721cm2 (266x647mm)
|
Takes less floor space |
 Price per pair* |
4998USD
vs
7000USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Masterpiece Classic ESL 9 |
Klipsch Heritage Forte IV |
| Brand |
MartinLogan |
Klipsch |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
20-400 watts |
up to 100 watts |
| Sensitivity |
90 dB |
99 dB |
| Impedance |
4 ohms |
8 ohms |
| Frequency Response |
34-23k Hz |
38-20k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
high-excursion paper cone |
Fibercomposite |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
9.2 x 44" |
1" |
| Tweeter Type |
curved electrostatic transducer |
horn-loaded |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
1.75" |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
1520.0mm (59.8") |
909.0mm (35.8") |
| Width |
266.0mm (10.5") |
423.0mm (16.7") |
| Depth |
647.0mm (25.5") |
331.0mm (13") |
| Weight |
35.45kg (78lbs) |
32.73kg (72lbs) |
| Enclosure |
Bass Reflex |
Passive Radiator |
| Finish |
Composite |
MDF/Wood veneer |
| Available Colors |
Gloss Black |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years w/ Registration |
10 Years |
| Labor Warranty |
5 Years w/ Registration |
10 Years |