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Focal Sib-T vs Klipsch R-51M Comparison

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Focal Sib-T

Passive Bookshelf | 80-20kHz

Focal Sib-T
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Klipsch R-51M

Passive Bookshelf | 62-21k Hz

Klipsch Reference R-51M
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Focal Sib-T Focal Sib-T
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Klipsch R-51M Klipsch R-51M
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Focal Sib-T
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Klipsch R-51M
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Focal Sib-T vs Klipsch R-51M Speaker Comparison

In this review, we will be comparing Sib-T and R-51M, two Passive Bookshelf speakers from Focal and Klipsch.

Let's have a brief look at the main features of Focal Sib-T and Klipsch R-51M first before getting into our more detailed comparison.

Focal Sib-T Key Specs

  • 2-way Design
  • .75" Dome Tweeter
  • 5.125" Polyflex Woofer
  • 80-20kHz Frequency Response
  • 90 dB Sensitivity
  • Impedance: 4ohms
  • Weight:2.60kg
  • Dimensions (H x W x D): 64.0" x 5-5/8" x 6-11/16"( 64.0 x 143.0 x 170.0mm )

Klipsch R-51M Key Specs

  • 2-way Design
  • 1" Tractrix Horn Tweeter
  • 5.25" Copper-spun IMG Woofer
  • 62-21k Hz Frequency Response
  • 93 dB Sensitivity
  • Impedance: 8ohms
  • Power Range:Up to 85watts
  • Weight:5.00kg
  • Dimensions (H x W x D): 338.0" x 7.0" x 8.4"( 338.0 x 178.0 x 215.0mm )

In the following sections, we will get into more detail in order to better understand how the Focal Sib-T and Klipsch R-51M 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

Both Sib-T and R-51M are 2-way speakers.

Driver Focal Sib-T Klipsch R-51M
Driver Setup 2-way 2-way
Tweeter .75-inch 1-inch
Midrange - -
Woofer 1 x 5.125-inch 1 x 5.25-inch

Sib-T features a .75" Dome Tweeter and 1 x 5.125" Polyflex Woofer . On the other hand, the R-51M features a 1" Tractrix Horn Tweeter and 1 x 5.25" Copper-spun IMG Woofer with a Crossover frequency at 1660Hz.

Frequency Response

Sib-T has a frequency range of 80-20kHz whereas R-51M has a frequency range of 62-21k Hz. With a minimum frequency of 62Hz, the R-51M can go significantly deeper on the low side and provide stronger bass compared to the Sib-T's min frequency of 80Hz.

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 Bookshelf class in our database.

Low Frequency

Bookshelf Speakers

Sib-T
R-51M
Min
Average
Max
High Frequency

Bookshelf Speakers

Focal Sib-T
Klipsch R-51M
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

Sib-T is a 4 ohms speaker compared to the R-51M 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 Sib-T can provide this impedance level.

These two speakers also have different sensitivity levels. Sib-T sensitivity is rated at 90 dB and the R-51M's is rated at 93 dB. This 3 dB difference makes the Klipsch R-51M a more sensitive speaker compared to Focal Sib-T, hence will play louder with the same amount of watts.

Sensitivity

Bookshelf Speakers

Sib-T
R-51M
Min
Average
Max

Input Type and Bi-Amping / Bi-Wiring

Sib-T features Single Gold Plated Binding Posts - 5-way type posts and R-51M has a Single Gold Plated Binding Posts - 5-way type posts. None of these speakers feature bi-amping/bi-wiring.

Focal Sib-T Terminals
Focal Sib-T's Spring posts terminals

Klipsch R-51MSingle Gold Plated Binding Posts - 5-way Terminals
Klipsch R-51M's Single Gold Plated Binding Posts - 5-way terminals

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 Focal Sib-T's and Klipsch R-51M's external dimensions. Focal Sib-T has external dimensions of 64.0 x 143.0 x 170.0mm ( 2-1/2 x 5-5/8 x 6-11/16inch) whereas Klipsch R-51M has external dimensions of 338.0 x 178.0 x 215.0mm ( 13.3 x 7.0 x 8.4inch) .

Klipsch R-51M is clearly the larger of the two speakers. Its body is 35mm wider, 274mm taller and 45mm deeper than Focal Sib-T.

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 Focal Sib-T is approximately 243.1cm2 / 37.7inch2 and base area of the Klipsch R-51M is approximately 382.7cm2 / 59.3inch2. The Sib-T requires 36% less surface area than the R-51M 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 Focal Sib-T weighs 2.60kg / 5.7lbs and the Klipsch R-51M weighs 5.00kg / 11lbs. This makes the R-51M 92% heavier than the Sib-T.

Here is a comparison of how Sib-T and R-51M's weights compare with the average, max and min weights in Passive Bookshelf class.

Weight
All Bookshelf Speakers
Focal Sib-T
Klipsch R-51M
Min
Average
Max

What's in the Box of Focal Sib-T?

Here are the items that are included inside the box of Sib-T:
  • One 100V/4-ohm commercial speaker
  • Adjustable mounting bracket (installed)
  • 3 Drywall anchors w/ 2 screws
  • 5mm Allen key (attached to mounting bracket)
  • User manual
  • What's in the Box of Klipsch R-51M?

    Here are the items that come with the R-51M:
  • 2 Bookshelf loudspeakers
  • 2 Grilles (installed)
  • 8 Self-adhesive rubber feet
  • Quick Setup Guide
  • Important Safety Instructions
  • Warranty Information

  • Reasons to choose Focal Sib-T over Klipsch Reference R-51M
    Mounting Bracket Yes vs No Allows mounting on walls
    Height 64mm vs 338mm Easier to fit in smaller spaces
    Base Surface Area 243cm2 vs 382cm2 Takes less floor space

    Reasons to choose Klipsch Reference R-51M over Focal Sib-T

    Sensitivity 93 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 5.25 inches vs 5.125 inches Larger woofer
    Low Frequency Response 62 Hz vs 80 Hz Generates deeper bass
    High Frequency Response 21k Hz vs 20k Hz Generates higher frequency
    Price per pair* 359USD vs 698USD costs less (*prices may change depending on the seller, location and time)
    Focal Sib-T vs Klipsch R-51M Specs Table
    Detailed comparison of specifications
    General Focal Sib-T Klipsch Reference R-51M
    Brand Focal Klipsch
    Speaker Type Bookshelf speakers Bookshelf speakers
    Sensitivity 90 dB 93 dB
    Impedance 4 ohms 8 ohms
    Frequency Response 80-20kHz 62-21k Hz
    Drivers
    Woofer Quantity 1 1
    Woofer Size 5.125" 5.25"
    Woofer Composition Polyflex Copper-spun IMG
    Woofer Surround Material Not given Rubber
    Tweeter Size .75" 1"
    Tweeter Type Dome Tractrix Horn
    Aimable Tweeter No No
    Midrange Driver No No
    Crossover Frequency n/a 1660Hz
    Firing Direction n/a rear
    Physical Specs
    Height 64.0mm (2.5") 338.0mm (13.3")
    Width 143.0mm (5.6") 178.0mm (7")
    Depth 170.0mm (6.7") 215.0mm (8.5")
    Weight 2.60kg (5.7lbs) 5.00kg (11lbs)
    Enclosure Bass Reflex Bass Reflex
    Finish Plastic MDF/Wood-grain vinyl
    Available Colors White Black
    Mounting Bracket Yes No
    Recommended Stand Height 2-1/2" 24-28"
    Grille n/a Yes
    Moisture Resistancy No No
    Connections
    Biamp Inputs No No
    Other
    Parts Warranty 5 Years 5 Years
    Labor Warranty 5 Years 5 Years

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