In this review, we will be comparing Prime Bookshelf and Q150, two Passive Bookshelf speakers from SVS and KEF.
Let's have a brief look at the main features
of SVS Prime Bookshelf and KEF Q150 first before getting into our more
detailed comparison.
| Key Specs | SVS Prime Bookshelf | KEF Q150 |
|---|
| Brand | SVS
United States · founded 1998 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | — | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Hard-Dome | 1" Dome |
|---|
| Woofer | 6.5" | 5.25" Aluminum |
|---|
| Frequency response | 48-25k Hz | 51-28k Hz |
|---|
| Sensitivity | 87 dB | 86 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 25-150 watts | 10-100 watts |
|---|
| Weight | 7.03kg / 15.5lbs | 5.60kg / 12.3lbs |
|---|
| Dimensions (H x W x D) | 13.2" x 8.0" x 10.2"
337.8 x 203.2 x 261.6mm | 11.9" x 7.0" x 10.9"
303.0 x 180.0 x 278.0mm |
|---|
What size room are the SVS Prime Bookshelf and KEF Q150 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* |
SVS Prime Bookshelf |
KEF Q150 |
| Near-field |
Poor |
Average |
| Small Room |
Average |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Poor |
| Very Large Room |
Poor |
Bad |
(* 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 Prime Bookshelf and Q150 are 2-way speakers.
SVS Prime BookshelfKEF Q150
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
SVS Prime Bookshelf |
KEF Q150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.25-inch
|
Prime Bookshelf features a 1" aluminum Hard-Dome Tweeter and 1 x 6.5" Woofer with a Crossover frequency at 2300Hz. On the other hand, the Q150 features a 1" vented aluminum Dome Tweeter and 1 x 5.25" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Prime Bookshelf has a frequency range of 48-25k Hz whereas Q150 has a frequency range of 51-28k Hz. With a minimum frequency of 48Hz, the Prime Bookshelf can go slightly deeper then the Q150's min frequency of 51Hz.
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
Prime Bookshelf and Q150 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Prime Bookshelf sensitivity is rated at 87 dB and the Q150's is at 86 dB. This 1 dB difference makes the SVS Prime Bookshelf a more sensitive speaker compared to KEF Q150, 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.
Prime Bookshelf can handle a max power of 150 watts RMS, whereas Q150 has a max power handling value of 100 watts RMS, 50 watts less than the Prime Bookshelf.
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
Prime Bookshelf features Post type posts and Q150 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
SVS Prime Bookshelf's 5-way post terminals
KEF Q150's Post terminals
Cabinet Type and Port Position
Both Prime Bookshelf and Q150 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 Q150 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 SVS Prime Bookshelf's and KEF Q150's external dimensions. SVS Prime Bookshelf has external dimensions of 337.8 x 203.2 x 261.6mm (13.2 x 8.0 x 10.2inch) whereas KEF Q150 has external dimensions of 303.0 x 180.0 x 278.0mm (11.9 x 7.0 x 10.9inch).
KEF Q150 is 23.2mm narrower and 34.8mm shorter than SVS Prime Bookshelf but it is also 16.4mm deeper.
Below you can see the front view size comparison of SVS Prime Bookshelf and KEF Q150 in scale.
Comparison image of SVS Prime Bookshelf and KEF Q150 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 SVS Prime Bookshelf is approximately 531.6cm2 / 82.4inch2 and base area of the KEF Q150 is approximately 500.4cm2 / 77.6inch2. The Prime Bookshelf requires 6% more surface area than the Q150 which gives it a small disadvantage on placement in tight spaces.
Here is another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
Size Comparison image of SVS Prime Bookshelf and KEF Q150 on a Media Console
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 SVS Prime Bookshelf weighs 7.03kg / 15.5lbs and the KEF Q150 weighs 5.60kg / 12.3lbs. This makes the Prime Bookshelf 26% heavier than the Q150.
Here is a comparison of how Prime Bookshelf and Q150's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of SVS Prime Bookshelf?
Here are the items that are included inside the box of Prime Bookshelf:
- 2 Bookshelf loudspeakers
- 2 Grilles (pre-installed)
- 8 Self-adhesive rubber bumpers
- Owners Manual SVS brochure
- Online Product Registration Card
What's in the Box of KEF Q150?
Here are the items that come with the Q150:
- 2 Bookshelf loudspeakers
- 2 Foam port plugs
- 8 Self-adhesive rubber feet
- Owner's Manual
- Warranty Registration Card
 Max Input Power |
150 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
87 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
48 Hz
vs
51 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
 Height |
303mm
vs
337mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
500cm2
vs
531cm2
|
Takes less floor space |
| General |
SVS Prime Bookshelf |
KEF Q150 |
| Brand |
SVS |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-150 watts |
10-100 watts |
| Sensitivity |
87 dB |
86 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
3.7 ohms |
| Frequency Response |
48-25k Hz |
51-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
5.25" |
| Woofer Composition |
|
Aluminum |
| Woofer Surround Material |
Polypropylene |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Hard-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2300Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
337.8mm (13.3") |
303.0mm (11.9") |
| Width |
203.2mm (8") |
180.0mm (7.1") |
| Depth |
261.6mm (10.3") |
278.0mm (10.9") |
| Weight |
7.03kg (15.5lbs) |
5.60kg (12.3lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
MDF/Vinyl-wrapped |
| Available Colors |
Black Ash,Piano Gloss Black |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
24-28" |
18-24" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
A generation apart: KEF Q150 is the newer design, against a 2015 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 | SVS Prime Bookshelf digs deeper - 48Hz against 51Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (87dB vs 86dB) - both want much the same power. |
| Headroom | A | SVS Prime Bookshelf takes more power (150W vs 100W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Price | evenly matched | Much the same money ($600 vs $600 a pair). |
A SVS Prime Bookshelf B KEF Q150
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?
SVS Prime Bookshelf has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. Match it to your room: we rate SVS Prime Bookshelf the better fit for a mid-size room and a large room, and KEF Q150 for near-field listening and a small room.
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.