In this review, we will be comparing two different type of speakers by KEF. KEF Q650c is a Center Channel speaker whereas the Q750 is a Floor-standing speaker.
Let's have a brief look at the main features
of KEF Q650c and KEF Q750 first before getting into our more
detailed comparison.
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 )
KEF Q750 Key Specs
- 2-way Design
- 11th Generation Uni-Q Driver
- 1" Dome Tweeter
- 2 x 6.5" Aluminum Woofer
- 48-28k Hz Frequency Response
- 88 dB Sensitivity
- Impedance: 8ohms
- Power Range:15-150watts
- Weight:16.59kg
- Dimensions (H x W x D): 945.0" x 12-7/8" x 12-3/8"( 945.0 x 328.0 x 315.0mm )
Q650c and Q750 are members of KEF's Q series of speakers. Below you can find the loudspeakers from this series.
What size room are the KEF Q650c and KEF Q750 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* |
KEF Q650c |
KEF Q750 |
| Near-field |
Poor |
Bad |
| Small Room |
Average |
Poor |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Good |
| 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 KEF Q650c and KEF Q750 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
Both Q650c and Q750 are 2-way speakers.
| Driver |
KEF Q650c |
KEF Q750 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
Q650c features a 1" vented aluminum Dome Tweeter and 2 x 6.5" aluminum Woofer with a Crossover frequency at 2500Hz. On the other hand, the Q750 features a 1" vented aluminum Dome Tweeter and 2 x 6.5" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Q650c has a frequency range of 64-28k Hz whereas Q750 has a frequency range of 48-28k Hz. With a minimum frequency of 48Hz, the Q750 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
High Frequency
Center Channel 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
Q650c and Q750 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q650c sensitivity is rated at 87 dB and the Q750's is at 88 dB. This 1 dB difference makes the KEF Q750 a more sensitive speaker compared to KEF Q650c, hence will play louder with the same amount of watts.
Sensitivity
Center Channel 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.
Q650c and Q750 has the same power range of 15-150 watts.
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
Q650c features Binding post type posts and Q750 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
KEF Q650c's Binding post terminals
KEF Q750'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 KEF Q650c's and KEF Q750's external dimensions. 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) whereas KEF Q750 has external dimensions of 945.0 x 328.0 x 315.0mm ( 37-3/16 x 12-7/8 x 12-3/8inch) .
KEF Q650c is 733mm shorter and 11mm less deeper than KEF Q750 but it is also 303mm 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 KEF Q650c is approximately 1918.2cm2 / 297.3inch2 and base area of the KEF Q750 is approximately 1033.2cm2 / 160.1inch2. The Q650c requires 86% more surface area than the Q750 which gives it a small disadvantage on placement in tight spaces.
What's in the Box of KEF Q650c?
Here are the items that are included inside the box of Q650c:
Center-channel loudspeaker 4 Self-adhesive rubber feet Owners Manual Warranty Information
What's in the Box of KEF Q750?
Here are the items that come with the Q750:
Floorstanding loudspeaker2 Outrigger feet4 Spikes6 Screws6 Washers4 Rubber insertsHex-keyOwners ManualWarranty Information
Minimum Impedance 
Height 
Price per pair* 
Sensitivity 
Low Frequency Response 
Dolby Atmos Drivers 
Base Surface Area