SpeakerDecision
  • SPEAKERS by TYPE
    • Passive Bookshelf Speakers
    • Passive Floor-standing Speakers
    • Passive Center Channel Speakers
    • Passive In-wall Speakers
    • All Passive Speakers
    • Powered Subwoofers
    • Powered Stereo Speakers
  • AMPLIFIERS
  • SMART FIND

AE109 Mark II vs Klipsch RP-4000F Comparison

x
Speaker to replace
Change

AE109 Mark II

Passive Floor-standing | 41Hz - 26kHz

Acoustic Energy AE109 Mark II
CHECK PRICE
Change
    
Klipsch RP-4000F

Passive Floor-standing | 37-25k Hz

Klipsch Reference Premiere RP-4000F
CHECK PRICE
AE109 Mark II AE109 Mark II
See at AMAZON
Klipsch RP-4000F Klipsch RP-4000F
See at AMAZON
AE109 Mark II
See at AMAZON
Klipsch RP-4000F
See at AMAZON
AE109 Mark II vs Klipsch RP-4000F Speaker Comparison

In this review, we will be comparing AE109 MII and RP-4000F, two Passive Floor-standing speakers from Acoustic Energy and Klipsch.

Let's have a brief look at the main features of AE109 Mark II and Klipsch RP-4000F first before getting into our more detailed comparison.

AE109 Mark II Key Specs

  • 3-way Design
  • 1" dome with waveguide Tweeter
  • 5.2" Midrange
  • 5.2" paper cone Woofer
  • 41Hz - 26kHz Frequency Response
  • 89 dB Sensitivity
  • Impedance: 6ohms
  • Power Range:up to 175watts
  • Weight:16.00kg
  • Dimensions (H x W x D): 860.0" x 6.5" x 9.8"( 860.0 x 165.0 x 250.0mm )

Klipsch RP-4000F Key Specs

  • 2-way Design
  • 1" Tractrix Horn Tweeter
  • 2 x 4" Cerametallic Woofer
  • 37-25k Hz Frequency Response
  • 95 dB Sensitivity
  • Impedance: 8ohms
  • Power Range:up to 75watts
  • Weight:13.18kg
  • Dimensions (H x W x D): 870.0" x 7-3/8" x 11-3/8"( 870.0 x 188.0 x 289.0mm )

What size room are the AE109 Mark II and Klipsch RP-4000F speakers good for?

The size of the room in which you are planning to use these loudspeakers is an important decision factor. Here we have compared their suitability to various sizes of environments considering their size and max power parameters:

Listening Environment* AE109 Mark II Klipsch RP-4000F
Near-field Bad Poor
Small Room Poor Average
Mid-size Room Good Good
Large Room Good Average
Very Large Room Poor No way

(* Approximate Room sizes: Small < 100sq. ft / 9 m2, Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: > 400 sq. ft / 36 m2. Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual listening experience changes depending on floor height, room shape, surface materials, listening position, speaker locations, etc.)

In the following sections, we will get into more detail in order to better understand how the AE109 Mark II and Klipsch RP-4000F compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.


**This post contains affiliate links, and I will be compensated if you make a purchase after clicking through my links. As an Amazon Associate I earn from qualifying purchases.


Drivers

One of the fundamental differences between these two speakers is that AE109 MII is a 3-way design whereas the RP-4000F 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.

Driver AE109 Mark II Klipsch RP-4000F
Driver Setup 3-way 2-way
Tweeter 1-inch 1-inch
Midrange 1 x 5.2-inch -
Woofer 1 x 5.2-inch 2 x 4-inch

AE109 MII features a 1" fabric dome with waveguide Tweeter , a 5.2" Midrange and 1 x 5.2" paper cone Woofer with a Crossover frequency at 275Hz and 2.5kHz. On the other hand, the RP-4000F features a 1" Tractrix Horn Tweeter and 2 x 4" Cerametallic Woofer .

Frequency Response

AE109 MII has a frequency range of 41Hz - 26kHz whereas RP-4000F has a frequency range of 37-25k Hz. With a minimum frequency of 37Hz, the RP-4000F can go slightly deeper then the AE109 MII's min frequency of 41Hz.

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

AE109 MII
RP-4000F
Min
Average
Max
High Frequency

Floor-standing Speakers

AE109 Mark II
Klipsch RP-4000F
Min
Average
Max

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

AE109 MII is a 6 ohms speaker compared to the RP-4000F which has a nominal impedance of 8 ohms.

These two speakers also have different sensitivity levels. AE109 MII sensitivity is rated at 89 dB and the RP-4000F's is rated at 95 dB. This 6 dB difference makes the Klipsch RP-4000F a more sensitive speaker compared to AE109 Mark II, hence will play louder with the same amount of watts.

Sensitivity

Floor-standing Speakers

AE109 MII
RP-4000F
Min
Average
Max

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.

AE109 MII can handle a max power of 175 watts RMS from the amp the whereas RP-4000F has a max power handling value of 75 watts RMS, 100 watts less than the AE109 MII.

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.

Cabinet Type and Port Position

Both AE109 MII and RP-4000F have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.

If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.

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 AE109 Mark II's and Klipsch RP-4000F's external dimensions. AE109 Mark II has external dimensions of 860.0 x 165.0 x 250.0mm ( 33.9 x 6.5 x 9.8inch) whereas Klipsch RP-4000F has external dimensions of 870.0 x 188.0 x 289.0mm ( 34-1/4 x 7-3/8 x 11-3/8inch) .

Klipsch RP-4000F is clearly the larger of the two speakers. Its body is 23mm wider, 10mm taller and 39mm deeper than AE109 Mark II.

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 AE109 Mark II is approximately 412.5cm2 / 63.9inch2 and base area of the Klipsch RP-4000F is approximately 543.3cm2 / 84.2inch2. The AE109 MII requires 24% less surface area than the RP-4000F 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 AE109 Mark II weighs 16.00kg / 35.2lbs and the Klipsch RP-4000F weighs 13.18kg / 29lbs. This makes the AE109 MII 21% heavier than the RP-4000F.

Here is a comparison of how AE109 MII and RP-4000F's weights compare with the average, max and min weights in Passive Floor-standing class.

Weight
All Floor-standing Speakers
AE109 Mark II
Klipsch RP-4000F
Min
Average
Max

What's in the Box of Klipsch RP-4000F?

Here are the items that come with the RP-4000F:
  • Floorstanding loudspeaker
  • Stabilizer feet (installed)
  • Grille (installed)
  • 2 Terminal jumpers (installed)
  • User Manual
  • Important Safety Instructions
  • Warranty Information

  • Reasons to choose Acoustic Energy AE109 Mark II over Klipsch Reference Premiere RP-4000F
    Max Input Power 175 watts vs 75 watts Handle more power from your amplifier
    Driver Setup 3-way vs 2-way Have a dedicated mid-range driver
    Woofer Size 5.2 inches vs 4 inches Larger woofer
    High Frequency Response 26k Hz vs 25k Hz Generates higher frequency
    Height 860mm vs 870mm Easier to fit in smaller spaces
    Base Surface Area 412cm2 vs 543cm2 Takes less floor space

    Reasons to choose Klipsch Reference Premiere RP-4000F over Acoustic Energy AE109 Mark II

    Sensitivity 95 dB vs 89 dB Play louder with same amount of amplification power
    Nominal Impedance 8 ohms vs 6 ohms Less selective with amplifiers
    Number of Woofers 2 vs 1 More woofers
    Low Frequency Response 37 Hz vs 41 Hz Generates deeper bass
    Price per pair* 698USD vs 999USD costs less (*prices may change depending on the seller, location and time)
    AE109 Mark II vs Klipsch RP-4000F Specs Table
    Detailed comparison of specifications
    General Acoustic Energy AE109 Mark II Klipsch Reference Premiere RP-4000F
    Brand Acoustic Energy Klipsch
    Speaker Type Floor-standing speaker Floor-standing speaker
    Power Range up to 175 watts up to 75 watts
    Sensitivity 89 dB 95 dB
    Impedance 6 ohms 8 ohms
    Frequency Response 41Hz - 26kHz 37-25k Hz
    Drivers
    Woofer Quantity 1 2
    Woofer Size 5.2" 4"
    Woofer Composition paper cone Cerametallic
    Woofer Surround Material n/a Rubber
    Tweeter Size 1" 1"
    Tweeter Type dome with waveguide Tractrix Horn
    Aimable Tweeter No No
    Midrange Driver 5.2" No
    Crossover Frequency 275Hz and 2.5kHz n/a
    Firing Direction rear rear
    Physical Specs
    Height 860.0mm (33.9") 870.0mm (34.3")
    Width 165.0mm (6.5") 188.0mm (7.4")
    Depth 250.0mm (9.8") 289.0mm (11.4")
    Weight 16.00kg (35.2lbs) 13.18kg (29lbs)
    Enclosure Bass Reflex Bass Reflex
    Finish HDF MDF/Wood-grain vinyl
    Available Colors Walnut, Satin Black Walnut, Black
    Grille Yes Yes
    Moisture Resistancy No No
    Connections
    Biamp Inputs n/a Yes
    Other
    Parts Warranty 5 Years
    Labor Warranty 5 Years

    Most Popular Speakers
    Klipsch Reference R-51M
    Klipsch R-51M
    2-way | 93 dB | 8 ohms
    Wharfedale Elysian 2
    Wharfedale Elysian 2
    3-way | 89 dB | 4 ohms
    ELAC Debut 2.0 B6.2
    ELAC Debut 2.0 B6.2
    2-way | 87 dB | 6 ohms
    Bowers & Wilkins 606 S2 Anniversary Edition
    B&W 606 S2
    2-way | 88 dB | 8 ohms
    KEF Q150
    KEF Q150
    2-way | 86 dB | 8 ohms
    Klipsch Reference Premiere RP-500M
    Klipsch RP-500M
    2-way | 93 dB | 8 ohms
    Wharfedale EVO4.1
    Wharfedale EVO4.1
    2-way | 87 dB | 8 ohms
    Bowers & Wilkins 606
    B&W 606
    2-way | 88 dB | 8 ohms
    Copyright © 2025 by SpeakerDecision
    About Privacy Contact US Camera Decision

    Report a Correction