In this review, we will be comparing S 803 and Q150, two Passive Bookshelf speakers from Jamo and KEF.
Let's have a brief look at the main features
of Jamo S 803 and KEF Q150 first before getting into our more
detailed comparison.
| Key Specs | Jamo S 803 | KEF Q150 |
|---|
| Brand | Jamo
Denmark · founded 1966 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | — | 11th Generation Uni-Q |
|---|
| Tweeter | 1" Soft-Dome | 1" Dome |
|---|
| Woofer | 5" Aluminized Polyfiber | 5.25" Aluminum |
|---|
| Frequency response | 57-26k Hz | 51-28k Hz |
|---|
| Sensitivity | 87 dB | 86 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | up to 80 watts | 10-100 watts |
|---|
| Weight | 5.40kg / 11.9lbs | 5.60kg / 12.3lbs |
|---|
| Dimensions (H x W x D) | 13.8" x 7.5" x 9.9"
353.0 x 191.0 x 252.0mm | 11.9" x 7.0" x 10.9"
303.0 x 180.0 x 278.0mm |
|---|
What size room are the Jamo S 803 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* |
Jamo S 803 |
KEF Q150 |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
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 S 803 and Q150 are 2-way speakers.
Jamo S 803KEF 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 |
Jamo S 803 |
KEF Q150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
1 x 5.25-inch
|
S 803 features a 1" Soft-Dome Tweeter and 1 x 5" Aluminized Polyfiber Woofer. 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
S 803 has a frequency range of 57-26k Hz whereas Q150 has a frequency range of 51-28k Hz. With a minimum frequency of 51Hz, the Q150 can go significantly deeper on the low side and provide stronger bass compared to the S 803's min frequency of 57Hz.
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
S 803 and Q150 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. S 803 sensitivity is rated at 87 dB and the Q150's is at 86 dB. This 1 dB difference makes the Jamo S 803 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.
Q150 can handle a max power of 100 watts RMS, whereas S 803 has a max power handling value of 80 watts RMS, 20 watts less than the Q150.
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
S 803 features Post type posts and Q150 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Jamo S 803's Post terminals
KEF Q150's Post terminals
Cabinet Type and Port Position
S 803 has a front firing port whereas Q150 has a rear firing ports. Jamo S 803's front-firing port gives more flexibility in placement in regards to proximity to walls compared to KEF Q150 with its rear-firing port.
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 Jamo S 803's and KEF Q150's external dimensions. Jamo S 803 has external dimensions of 353.0 x 191.0 x 252.0mm (13.8 x 7.5 x 9.9inch) 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 11mm narrower and 50mm shorter than Jamo S 803 but it is also 26mm deeper.
Below you can see the front view size comparison of Jamo S 803 and KEF Q150 in scale.
Comparison image of Jamo S 803 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 Jamo S 803 is approximately 481.3cm2 / 74.6inch2 and base area of the KEF Q150 is approximately 500.4cm2 / 77.6inch2. The S 803 requires 4% less surface area than the Q150 which gives it a small advantage 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 Jamo S 803 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 Jamo S 803 weighs 5.40kg / 11.9lbs and the KEF Q150 weighs 5.60kg / 12.3lbs. This makes the Q150 4% heavier than the S 803.
Here is a comparison of how S 803 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 Jamo S 803?
Here are the items that are included inside the box of S 803:
- 2 Bookshelf loudspeakers
- 2 Grilles
- User Manual
- Important Safety Instructions
- Warranty Information
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
 Sensitivity |
87 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Base Surface Area |
481cm2
vs
500cm2
|
Takes less floor space |
 Price per pair* |
229USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
100 watts
vs
80 watts
|
Handle more power from your amplifier |
 Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
|
Low Frequency Response |
51 Hz
vs
57 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
26k Hz
|
Generates higher frequency |
 Height |
303mm
vs
353mm
|
Easier to fit in smaller spaces |
| General |
Jamo S 803 |
KEF Q150 |
| Brand |
Jamo |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
up to 80 watts |
10-100 watts |
| Sensitivity |
87 dB |
86 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
3.7 ohms |
| Frequency Response |
57-26k Hz |
51-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5" |
5.25" |
| Woofer Composition |
Aluminized Polyfiber |
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 |
n/a |
2500Hz |
| Firing Direction |
front |
rear |
Physical Specs |
|
|
| Height |
353.0mm (13.9") |
303.0mm (11.9") |
| Width |
191.0mm (7.5") |
180.0mm (7.1") |
| Depth |
252.0mm (9.9") |
278.0mm (10.9") |
| Weight |
5.40kg (11.9lbs) |
5.60kg (12.3lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Vinyl |
MDF/Vinyl-wrapped |
| Available Colors |
Walnut, Black, White |
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 |
These sit in different price classes - KEF Q150 costs roughly 2.6x what Jamo S 803 does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | B | KEF Q150 digs deeper - 51Hz against 57Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (87dB vs 86dB) - both want much the same power. |
| Headroom | B | KEF Q150 takes more power (100W vs 80W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Price | A | Jamo S 803 is cheaper - $229 against $600, about 62% less; arguably a different class. |
A Jamo S 803 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?
The usual trade-off: KEF Q150 measures better, Jamo S 803 costs about about 2.6x the price% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 57Hz anyway, which makes the cheaper Jamo S 803 much easier to justify. Think about the whole system, not just the speakers: the roughly $371 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
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.