In this review, we will be comparing Ultra Bookshelf and Q350, two Passive Bookshelf speakers from SVS and KEF. Let's have a brief look at the main features
of SVS Ultra Bookshelf and KEF Q350 first before getting into our more
detailed comparison.
What size room are the SVS Ultra Bookshelf and KEF Q350 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:
In the following sections, we will get into more detail in order to better understand how the SVS Ultra Bookshelf and KEF Q350 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
Both Ultra Bookshelf and Q350 are 2-way speakers.
| Driver |
SVS Ultra Bookshelf |
KEF Q350 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 6.5-inch
|
Ultra Bookshelf features a 1" aluminum Hard-Dome Tweeter and 1 x 6.5" Composite glass-fiber Woofer with a Crossover frequency at 2000Hz. On the other hand, the Q350 features a 1" vented aluminum Dome Tweeter and 1 x 6.5" Aluminum Woofer with a Crossover frequency at 2500Hz.
Frequency Response
Ultra Bookshelf has a frequency range of 45-32k Hz whereas Q350 has a frequency range of 63-28k Hz. With a minimum frequency of 45Hz, the Ultra Bookshelf can go significantly deeper on the low side and provide stronger bass compared to the Q350's min frequency of 63Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
High Frequency
Bookshelf Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
Ultra Bookshelf and Q350 have the same Impedance of 8 ohms and their sensitivity is also same at 87 dB.
Sensitivity
Bookshelf Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
Ultra Bookshelf can handle a max power of 150 watts RMS from the amp the whereas Q350 has a max power handling value of 120 watts RMS, 30 watts less than the Ultra Bookshelf.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
Ultra Bookshelf features 5-way post posts which make bi-amping or bi-wiring possible. Q350 has a Post which doesn't feature bi-amping/bi-wiring.
SVS Ultra Bookshelf's 5-way post terminals allows Bi-amping or bi-wiring
KEF Q350's Post terminals
Cabinet Type and Port Position
Both Ultra Bookshelf and Q350 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.
Physical Specs
Size of a speaker can sometimes become 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 Ultra Bookshelf's and KEF Q350's external dimensions. SVS Ultra Bookshelf has external dimensions of 380.0 x 218.0 x 281.0mm ( 14-15/16 x 8-9/16 x 11-1/16inch) whereas KEF Q350 has external dimensions of 358.0 x 210.0 x 306.0mm ( 14.0 x 8.2 x 12.0inch) .
KEF Q350 is 8mm narrower and 22mm shorter than SVS Ultra Bookshelf but it is also 25mm deeper.
Below you can see the front view size comparison of SVS Ultra Bookshelf and KEF Q350 in scale.
Comparison image of SVS Ultra Bookshelf and KEF Q350 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 Ultra Bookshelf is approximately 612.6cm2 / 95.0inch2 and base area of the KEF Q350 is approximately 642.6cm2 / 99.6inch2. The Ultra Bookshelf requires 5% less surface area than the Q350 which gives it a small advantage on placement in tight spaces.
Here is an 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 Ultra Bookshelf and KEF Q350 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 Ultra Bookshelf weighs 8.64kg / 19lbs and the KEF Q350 weighs 7.60kg / 16.7lbs. This makes the Ultra Bookshelf 14% heavier than the Q350.
Here is a comparison of how Ultra Bookshelf and Q350'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 Ultra Bookshelf?
Here are the items that are included inside the box of Ultra Bookshelf:
2 Bookshelf loudspeakers2 Grilles8 Rubber feet2 Terminal jumpers (pre-installed)Owners ManualSVS brochureOnline Product Registration Card
What's in the Box of KEF Q350?
Here are the items that come with the Q350:
2 Bookshelf loudspeakers 2 Foam port plugs 8 Self-adhesive rubber feet Owner's Manual Warranty Registration Card
 Max Input Power |
150 watts
vs
120 watts
|
Handle more power from your amplifier |
 Low Frequency Response |
45 Hz
vs
63 Hz
|
Generates deeper bass |
 High Frequency Response |
32k Hz
vs
28k Hz
|
Generates higher frequency |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Base Surface Area |
612cm2 (218x281mm)
vs
642cm2 (210x306mm)
|
Takes less floor space |
 Height |
358mm
vs
380mm
|
Easier to fit in smaller spaces |
 Price per pair* |
750USD
vs
1200USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
SVS Ultra Bookshelf |
KEF Q350 |
| Brand |
SVS |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-150 watts |
10-120 watts |
| Sensitivity |
87 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
3.7 ohms |
| Frequency Response |
45-32k Hz |
63-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Composite glass-fiber |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Hard-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2000Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
380.0mm (15") |
358.0mm (14.1") |
| Width |
218.0mm (8.6") |
210.0mm (8.3") |
| Depth |
281.0mm (11.1") |
306.0mm (12") |
| Weight |
8.64kg (19lbs) |
7.60kg (16.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Oak veneer |
MDF/Vinyl-wrapped |
| Available Colors |
Black Oak,Piano Gloss Black,Piano Gloss White |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
22-28" |
18-24" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |