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MartinLogan Foundation C1 vs KEF Q650c Comparison

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MartinLogan Foundation C1

Passive Center Channel | 53-23k Hz

MartinLogan Foundation C1
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KEF Q650c

Passive Center Channel | 64-28k Hz

KEF Q650c
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MartinLogan Foundation C1 MartinLogan Foundati...
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KEF Q650c KEF Q650c
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MartinLogan Foundati...
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KEF Q650c
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MartinLogan Foundation C1 vs KEF Q650c Speaker Comparison

In this review, we will be comparing MartinLogan Foundation C1 and Q650c, two Passive Center Channel speakers from MartinLogan and KEF.

Let's have a brief look at the main features of MartinLogan Foundation C1 and KEF Q650c first before getting into our more detailed comparison.

MartinLogan Foundation C1 Key Specs

  • 2-way Design
  • 1" Folded Motion Ribbon Tweeter
  • 2 x 5-1/2" Aluminum Woofer
  • 53-23k Hz Frequency Response
  • 91 dB Sensitivity
  • Impedance: 4ohms
  • Power Range:up to 150watts
  • Weight:8.18kg
  • Dimensions (H x W x D): 194.0" x 20" x 10"( 194.0 x 508.0 x 254.0mm )

KEF Q650c Key Specs

  • 2-way Design
  • 11th Generation Uni-Q Driver
  • 1" Dome Tweeter
  • 2 x 6.5" aluminum Woofer
  • 64-28k Hz Frequency Response
  • 87 dB Sensitivity
  • Impedance: 8ohms
  • Power Range:15-150watts
  • Weight:13.64kg
  • Dimensions (H x W x D): 212.0" x 24-13/16" x 11-15/16"( 212.0 x 631.0 x 304.0mm )

What size room are the MartinLogan Foundation C1 and KEF Q650c 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* MartinLogan Foundation C1 KEF Q650c
Near-field Poor Poor
Small Room Average Average
Mid-size Room Good Good
Large Room Average Average
Very Large Room Poor Poor

(* 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 MartinLogan Foundation C1 and KEF Q650c 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 MartinLogan Foundation C1 and Q650c are 2-way speakers.

Driver MartinLogan Foundation C1 KEF Q650c
Driver Setup 2-way 2-way
Tweeter 1-inch 1-inch
Midrange - -
Woofer 2 x 5-1/2-inch 2 x 6.5-inch

MartinLogan Foundation C1 features a 1" Gen2 Obsidian Folded Motion Ribbon Tweeter and 2 x 5-1/2" Aluminum Woofer with a Crossover frequency at 2900 Hz - 3200 Hz. On the other hand, the Q650c features a 1" vented aluminum Dome Tweeter and 2 x 6.5" aluminum Woofer with a Crossover frequency at 2500Hz.

Frequency Response

MartinLogan Foundation C1 has a frequency range of 53-23k Hz whereas Q650c has a frequency range of 64-28k Hz. With a minimum frequency of 53Hz, the MartinLogan Foundation C1 can go significantly deeper on the low side and provide stronger bass compared to the Q650c's min frequency of 64Hz.

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 Center Channel class in our database.

Low Frequency

Center Channel Speakers

MartinLogan Foundation C1
Q650c
Min
Average
Max
High Frequency

Center Channel Speakers

MartinLogan Foundation C1
KEF Q650c
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

MartinLogan Foundation C1 is a 4 ohms speaker compared to the Q650c 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 MartinLogan Foundation C1 can provide this impedance level.

These two speakers also have different sensitivity levels. MartinLogan Foundation C1 sensitivity is rated at 91 dB and the Q650c's is rated at 87 dB. This 4 dB difference makes the MartinLogan Foundation C1 a more sensitive speaker compared to KEF Q650c, hence will play louder with the same amount of watts.

Sensitivity

Center Channel Speakers

MartinLogan Foundation C1
Q650c
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.

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

MartinLogan Foundation C1 features Binding post type posts and Q650c has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.

MartinLogan Foundation C1 Terminals
MartinLogan Foundation C1's Binding post terminals

KEF Q650cBinding post Terminals
KEF Q650c's Binding post 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 MartinLogan Foundation C1's and KEF Q650c's external dimensions. MartinLogan Foundation C1 has external dimensions of 194.0 x 508.0 x 254.0mm ( 7-5/8inch x 20inch x 10inch ) whereas KEF Q650c has external dimensions of 212.0 x 631.0 x 304.0mm ( 8-5/16 x 24-13/16 x 11-15/16inch) .

KEF Q650c is clearly the larger of the two speakers. Its body is 123mm wider, 18mm taller and 50mm deeper than MartinLogan Foundation C1.

Below you can see the front view size comparison of MartinLogan Foundation C1 and KEF Q650c in scale.

MartinLogan Foundation C1 vs KEF Q650c Size Comparison - Front View
Comparison image of MartinLogan Foundation C1 and KEF Q650c 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 MartinLogan Foundation C1 is approximately 1290.3cm2 / 200.0inch2 and base area of the KEF Q650c is approximately 1918.2cm2 / 297.3inch2. The MartinLogan Foundation C1 requires 33% less surface area than the Q650c 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 MartinLogan Foundation C1 weighs 8.18kg / 18lbs and the KEF Q650c weighs 13.64kg / 30lbs. This makes the Q650c 67% heavier than the MartinLogan Foundation C1.

Here is a comparison of how MartinLogan Foundation C1 and Q650c's weights compare with the average, max and min weights in Passive Center Channel class.

Weight
All Center Channel Speakers
MartinLogan Foundation C1
KEF Q650c
Min
Average
Max

What's in the Box of KEF Q650c?

Here are the items that come with the Q650c:
  • Center-channel loudspeaker
  • 4 Self-adhesive rubber feet
  • Owners Manual
  • Warranty Information

  • Reasons to choose MartinLogan Foundation C1 over KEF Q650c
    Sensitivity 91 dB vs 87 dB Play louder with same amount of amplification power
    Low Frequency Response 53 Hz vs 64 Hz Generates deeper bass
    Height 194mm vs 212mm Easier to fit in smaller spaces
    Base Surface Area 1290cm2 vs 1918cm2 Takes less floor space
    Price per pair* 499USD vs 750USD costs less (*prices may change depending on the seller, location and time)

    Reasons to choose KEF Q650c over MartinLogan Foundation C1

    Nominal Impedance 8 ohms vs 4 ohms Less selective with amplifiers
    Woofer Size 6.5 inches vs 5-1/2 inches Larger woofer
    High Frequency Response 28k Hz vs 23k Hz Generates higher frequency
    Passive Radiator one 6.5-inch vs None Increases the bass performance
    MartinLogan Foundation C1 vs KEF Q650c Specs Table
    Detailed comparison of specifications
    General MartinLogan Foundation C1 KEF Q650c
    Brand MartinLogan KEF
    Speaker Type Center channel speaker Center channel speaker
    Power Range up to 150 watts 15-150 watts
    Sensitivity 91 dB 87 dB
    Impedance 4 ohms 8 ohms
    Impedance n/a 4.2 ohms
    Frequency Response 53-23k Hz 64-28k Hz
    Drivers
    Woofer Quantity 2 2
    Woofer Size 5-1/2" 6.5"
    Woofer Composition Aluminum aluminum
    Woofer Surround Material n/a Rubber
    Tweeter Size 1" 1"
    Tweeter Type Folded Motion Ribbon Dome
    Aimable Tweeter No No
    Midrange Driver No No
    Crossover Frequency 2900 Hz - 3200 Hz 2500Hz
    Firing Direction rear n/a
    Physical Specs
    Height 194.0mm (7.6") 212.0mm (8.3")
    Width 508.0mm (20") 631.0mm (24.8")
    Depth 254.0mm (10") 304.0mm (12")
    Weight 8.18kg (18lbs) 13.64kg (30lbs)
    Enclosure Bass Reflex Passive Radiator
    Available Colors Walnut,Black,Satin White Satin White, Satin Black, Walnut
    Grille Yes optional
    Moisture Resistancy No No
    Connections
    Biamp Inputs No n/a
    Other
    Parts Warranty 5 years 5 Years
    Labor Warranty 5 years 5 Years

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