In this review, we will be comparing two different types of speakers by KEF. KEF Q750 is a Floor-standing speaker whereas the Q650c is a Center Channel speaker.
Let's have a brief look at the main features
of KEF Q750 and KEF Q650c first before getting into our more
detailed comparison.
| Key Specs | KEF Q750 | KEF Q650c |
|---|
| Brand | KEF
United Kingdom · founded 1961 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | 11th Generation Uni-Q | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Dome | 1" Dome |
|---|
| Woofer | 2 x 6.5" Aluminum | 2 x 6.5" aluminum |
|---|
| Frequency response | 48-28k Hz | 64-28k Hz |
|---|
| Sensitivity | 88 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 15-150 watts | 15-150 watts |
|---|
| Weight | 16.59kg / 36.5lbs | 13.64kg / 30lbs |
|---|
| Dimensions (H x W x D) | 37-3/16" x 12-7/8" x 12-3/8"
945.0 x 328.0 x 315.0mm | 8-5/16" x 24-13/16" x 11-15/16"
212.0 x 631.0 x 304.0mm |
|---|
Q750 and Q650c are members of KEF's Q series of speakers. Below you can find the loudspeakers from this series.
What size room are the KEF Q750 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* |
KEF Q750 |
KEF Q650c |
| Near-field |
Bad |
Poor |
| Small Room |
Poor |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Good |
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.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Q750 and Q650c are 2-way speakers.
KEF Q750KEF Q650c
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
KEF Q750 |
KEF Q650c |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
Q750 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 Q650c features a 1" vented aluminum Dome Tweeter and 2 x 6.5" aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Q750 has a frequency range of 48-28k Hz whereas Q650c has a frequency range of 64-28k 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.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
Q750 and Q650c have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Q750 sensitivity is rated at 88 dB and the Q650c's is at 87 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
Floor-standing Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
Q750 and Q650c have the same power range of 15-150 watts.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
Input Type and Bi-Amping / Bi-Wiring
Q750 features Binding post type posts and Q650c has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
KEF Q750's Binding post terminals
KEF Q650c's Binding post terminals
Physical Specs
The size of a speaker can sometimes be 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 Q750's and KEF Q650c's external dimensions. 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) 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 733mm shorter and 11mm less deeper than KEF Q750 but it is also 303mm wider.
Below you can see the front view size comparison of KEF Q750 and KEF Q650c in scale.
Comparison image of KEF Q750 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 KEF Q750 is approximately 1033.2cm2 / 160.1inch2 and base area of the KEF Q650c is approximately 1918.2cm2 / 297.3inch2. The Q750 requires 46% less surface area than the Q650c which gives it a small advantage on placement in tight spaces.
What's in the Box of KEF Q750?
Here are the items that are included inside the box of Q750:
- Floorstanding loudspeaker
- 2 Outrigger feet
- 4 Spikes
- 6 Screws
- 6 Washers
- 4 Rubber inserts
- Hex-key
- Owners Manual
- Warranty Information
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