In this review, we will be comparing Concept 300 and R3, two Passive Bookshelf speakers from Q Acoustics and KEF.
Let's have a brief look at the main features
of Q Acoustics Concept 300 and KEF R3 first before getting into our more
detailed comparison.
| Key Specs | Q Acoustics Concept 300 | KEF R3 |
|---|
| Brand | Q Acoustics
United Kingdom · founded 2006 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 3-way |
|---|
| Uni-Q driver | — | 12th Generation Uni-Q |
|---|
| Tweeter | 1.1" Dome | 1" Dome |
|---|
| Midrange | — | 5" |
|---|
| Woofer | 6.5" Paper composite | 6.5" Hybrid aluminum |
|---|
| Frequency response | 55-30k Hz | 52-28k Hz |
|---|
| Sensitivity | 84 dB | 87 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | 25-200 watts | 15-180 watts |
|---|
| Weight | 14.50kg / 31.9lbs | 13.55kg / 29.8lbs |
|---|
| Dimensions (H x W x D) | 14" x 7-7/8" x 15-3/4"
355.0 x 200.0 x 400.0mm | 16-5/8" x 7-13/16" x 13-1/4"
423.0 x 199.0 x 337.0mm |
|---|
What size room are the Q Acoustics Concept 300 and KEF R3 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 Concept 300 |
KEF R3 |
| 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.
Drivers
One of the fundamental differences between these two speakers is that Concept 300 is a 2-way design whereas the R3 is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
Q Acoustics Concept 300KEF R3
TweeterMidrangeWoofer
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 Concept 300 |
KEF R3 |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1.1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 5-inch |
|
Woofer
|
1 x 6.5-inch
|
1 x 6.5-inch
|
Concept 300 features a 1.1" Dome Tweeter and 1 x 6.5" Paper composite Woofer with a Crossover frequency at 2500Hz. On the other hand, the R3 features a 1" aluminum Dome Tweeter, a 5" Midrange and 1 x 6.5" Hybrid aluminum Woofer with a Crossover frequency at 400Hz and 2900Hz.
Frequency Response
Concept 300 has a frequency range of 55-30k Hz whereas R3 has a frequency range of 52-28k Hz. With a minimum frequency of 52Hz, the R3 can go slightly deeper then the Concept 300's min frequency of 55Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf 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
Concept 300 is a 6 ohms speaker compared to the R3 which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. Concept 300 sensitivity is rated at 84 dB and the R3's is rated at 87 dB. This 3 dB difference makes the KEF R3 a more sensitive speaker compared to Q Acoustics Concept 300, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf 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.
Concept 300 can handle a max power of 200 watts RMS, whereas R3 has a max power handling value of 180 watts RMS, 20 watts less than the Concept 300.
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
Both Concept 300 and R3 features dual binding post speaker terminals for bi-amping or bi-wiring.
Cabinet Type and Port Position
Both Concept 300 and R3 have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
KEF R3 Port
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 Concept 300's and KEF R3's external dimensions. Q Acoustics Concept 300 has external dimensions of 355.0 x 200.0 x 400.0mm (14 x 7-7/8 x 15-3/4inch) whereas KEF R3 has external dimensions of 423.0 x 199.0 x 337.0mm (16-5/8 x 7-13/16 x 13-1/4inch).
KEF R3 is 1mm narrower and 63mm less deeper than Q Acoustics Concept 300 but it is also 68mm taller.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Q Acoustics Concept 300 needs about 19% more floor or shelf area. Q Acoustics Concept 300 is 63mm deeper, so it stands that much further out from the wall. KEF R3 is 68mm taller.
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 Concept 300 is approximately 800.0cm2 / 124.0inch2 and base area of the KEF R3 is approximately 670.6cm2 / 103.9inch2. The Concept 300 requires 19% more surface area than the R3 which gives it a small disadvantage 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 Concept 300 weighs 14.50kg / 31.9lbs and the KEF R3 weighs 13.55kg / 29.8lbs. This makes the Concept 300 7% heavier than the R3.
Here is a comparison of how Concept 300 and R3's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of KEF R3?
Here are the items that come with the R3:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 2 Foam port plugs
- 8 Self-adhesive rubber feet
- User Manual
- Warranty Information
 Max Input Power |
200 watts
vs
180 watts
|
Handle more power from your amplifier |
 Minimum Impedance |
4.7 ohms
vs
3.2 ohms
|
Very low impedance levels puts more pressure on amplifier |
 High Frequency Response |
30k Hz
vs
28k Hz
|
Generates higher frequency |
 Height |
355mm
vs
423mm
|
Easier to fit in smaller spaces |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
87 dB
vs
84 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Low Frequency Response |
52 Hz
vs
55 Hz
|
Generates deeper bass |
 Base Surface Area |
670cm2
vs
800cm2
|
Takes less floor space |
 Price per pair* |
2200USD
vs
2749USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Q Acoustics Concept 300 |
KEF R3 |
| Brand |
Q Acoustics |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-200 watts |
15-180 watts |
| Sensitivity |
84 dB |
87 dB |
| Impedance |
6 ohms |
8 ohms |
| Impedance |
4.7 ohms |
3.2 ohms |
| Frequency Response |
55-30k Hz |
52-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Paper composite |
Hybrid aluminum |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1.1" |
1" |
| Tweeter Type |
Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
5" |
| Crossover Frequency |
2500Hz |
400Hz and 2900Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
355.0mm (14") |
423.0mm (16.7") |
| Width |
200.0mm (7.9") |
199.0mm (7.8") |
| Depth |
400.0mm (15.7") |
337.0mm (13.3") |
| Weight |
14.50kg (31.9lbs) |
13.55kg (29.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF/Lacquer |
| Available Colors |
n/a |
Black Gloss, White Gloss, Walnut |
| Mounting Bracket |
|
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | B | KEF R3 digs deeper - 52Hz against 55Hz. A subwoofer would even that out. |
| Amplifier needs | B | KEF R3 is more sensitive (87dB vs 84dB), so it goes louder on the same amplifier. |
| Amplifier match | B | KEF R3 is the easier load at 8 ohms. |
| Headroom | evenly matched | Similar power handling (200W vs 180W). |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Q Acoustics Concept 300: bi-amping; KEF R3: bi-amping. |
| Price | B | KEF R3 is cheaper - $2,200 against $2,749, about 20% less. |
A Q Acoustics Concept 300 B KEF R3
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?
KEF R3 is the easier recommendation: it leads on most of the measured areas and costs less. Take Q Acoustics Concept 300 if its size, looks or fit in your room suit you better. If your amplifier is modest, vintage or valve-based, KEF R3 is the safer partner - the other will want more current or more watts to sound its best.
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.