In this review, we will be comparing 5090 and Q650c, two Passive Center Channel speakers from Q Acoustics and KEF.
Let's have a brief look at the main features
of Q Acoustics 5090 and KEF Q650c first before getting into our more
detailed comparison.
| Key Specs | Q Acoustics 5090 | KEF Q650c |
|---|
| Brand | Q Acoustics
United Kingdom · founded 2006 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | — | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Soft-dome | 1" Dome |
|---|
| Woofer | 2 x 4.5" Coated paper | 2 x 6.5" aluminum |
|---|
| Frequency response | 57-30k Hz | 64-28k Hz |
|---|
| Sensitivity | 90.5 dB | 87 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | 25-150 watts | 15-150 watts |
|---|
| Weight | 8.50kg / 18.7lbs | 13.64kg / 30lbs |
|---|
| Dimensions (H x W x D) | 6-1/2" x 16-15/16" x 9-5/8"
166.0 x 431.0 x 245.0mm | 8-5/16" x 24-13/16" x 11-15/16"
212.0 x 631.0 x 304.0mm |
|---|
What size room are the Q Acoustics 5090 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* |
Q Acoustics 5090 |
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.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
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Drivers
Both 5090 and Q650c are 2-way speakers.
Q Acoustics 5090KEF 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 |
Q Acoustics 5090 |
KEF Q650c |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4.5-inch
|
2 x 6.5-inch
|
5090 features a 1" Soft-dome Tweeter and 2 x 4.5" Coated paper Woofer with a Crossover frequency at 2100 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
5090 has a frequency range of 57-30k Hz whereas Q650c has a frequency range of 64-28k Hz. With a minimum frequency of 57Hz, the 5090 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 Center Channel class in our database.
Low Frequency
Center Channel 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
5090 is a 6 ohms speaker compared to the Q650c which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. 5090 sensitivity is rated at 90.5 dB and the Q650c's is rated at 87 dB. This 4 dB difference makes the Q Acoustics 5090 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. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
Both handle the same maximum of 150 watts RMS, though 5090 is rated 25-150 watts and Q650c 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
5090 features Binding post type posts and Q650c has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
Q Acoustics 5090'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 Q Acoustics 5090's and KEF Q650c's external dimensions. Q Acoustics 5090 has external dimensions of 166.0 x 431.0 x 245.0mm (6-1/2inch x 16-15/16inch x 9-5/8inch) 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 clearly the larger of the two speakers. Its body is 200mm wider, 46mm taller and 59mm deeper than Q Acoustics 5090.
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 Q Acoustics 5090 is approximately 1056.0cm2 / 163.7inch2 and base area of the KEF Q650c is approximately 1918.2cm2 / 297.3inch2. The 5090 requires 45% 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 Q Acoustics 5090 weighs 8.50kg / 18.7lbs and the KEF Q650c weighs 13.64kg / 30lbs. This makes the Q650c 60% heavier than the 5090.
Here is a comparison of how 5090 and Q650c's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
What's in the Box of Q Acoustics 5090?
Here are the items that are included inside the box of 5090:
- 1x 5090 loudspeaker
- 1x Owners manual
- 2x Foam bung
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
 Sensitivity |
91 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
57 Hz
vs
64 Hz
|
Generates deeper bass |
 High Frequency Response |
30k Hz
vs
28k Hz
|
Generates higher frequency |
 Height |
166mm
vs
212mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1056cm2
vs
1918cm2
|
Takes less floor space |
 Price per pair* |
599USD
vs
750USD
|
costs less (*prices may change depending on the seller, location and time) |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Minimum Impedance |
4.2 ohms
vs
3.2 ohms
|
Very low impedance levels puts more pressure on amplifier |
|
Woofer Size |
6.5 inches
vs
4.5 inches
|
Larger woofer |
|
Passive Radiator |
one 6.5-inch
vs
None
|
Increases the bass performance |
| General |
Q Acoustics 5090 |
KEF Q650c |
| Brand |
Q Acoustics |
KEF |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
25-150 watts |
15-150 watts |
| Sensitivity |
90.5 dB |
87 dB |
| Impedance |
6 ohms |
8 ohms |
| Impedance |
3.2 ohms |
4.2 ohms |
| Frequency Response |
57-30k Hz |
64-28k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
4.5" |
6.5" |
| Woofer Composition |
Coated paper |
aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2100 Hz |
2500Hz |
| Firing Direction |
rear |
n/a |
Physical Specs |
|
|
| Height |
166.0mm (6.5") |
212.0mm (8.3") |
| Width |
431.0mm (17") |
631.0mm (24.8") |
| Depth |
245.0mm (9.6") |
304.0mm (12") |
| Weight |
8.50kg (18.7lbs) |
13.64kg (30lbs) |
| Enclosure |
Bass Relfex |
Passive Radiator |
| Finish |
MDF |
n/a |
| Available Colors |
Holme Oak,Satin Black,Satin White,Santos Rosewood |
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 |
A generation apart: Q Acoustics 5090 is the newer design, against a 2017 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | A | Q Acoustics 5090 digs deeper - 57Hz against 64Hz. A subwoofer would even that out. |
| Amplifier needs | A | Q Acoustics 5090 is more sensitive (91dB vs 87dB), so it goes louder on the same amplifier. |
| Amplifier match | B | KEF Q650c is the easier load at 8 ohms. |
| Headroom | evenly matched | Similar power handling (150W vs 150W). |
| Size | depends | Q Acoustics 5090 is easier to place; KEF Q650c is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Ported vs Passive Radiator. |
| Price | A | Q Acoustics 5090 is cheaper - $599 against $750, about 20% less. |
A Q Acoustics 5090 B KEF Q650c
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Q Acoustics 5090 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 64Hz anyway, so judge these on the other rows instead. In a large or open-plan room, KEF Q650c has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Q Acoustics 5090 is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.