In this review, we will be comparing Theva No1 and Q350, two Passive Bookshelf speakers from Focal and KEF.
Let's have a brief look at the main features
of Focal Theva No1 and KEF Q350 first before getting into our more
detailed comparison.
| Key Specs | Focal Theva No1 | KEF Q350 |
|---|
| Brand | Focal
France · founded 1979 | KEF
United Kingdom · founded 1961 |
|---|
| Design | 2-way | 2-way |
|---|
| Uni-Q driver | — | 11th Generation Uni-Q |
|---|
| Tweeter | 1" inverted dome | 1" Dome |
|---|
| Woofer | 6.5" Slatefiber | 6.5" Aluminum |
|---|
| Frequency response | 58-28kHz | 63-28k Hz |
|---|
| Sensitivity | 89 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 25-120 watts | 10-120 watts |
|---|
| Weight | 6.82kg / 15lbs | 7.60kg / 16.7lbs |
|---|
| Dimensions (H x W x D) | 15-3/8" x 8-3/8" x 10-1/4"
391.0 x 213.0 x 261.0mm | 14.0" x 8.2" x 12.0"
358.0 x 210.0 x 306.0mm |
|---|
What size room are the Focal Theva No1 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:
| Listening Environment* |
Focal Theva No1 |
KEF Q350 |
| 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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through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both Theva No1 and Q350 are 2-way speakers.
Focal Theva No1KEF Q350
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Focal Theva No1 |
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
|
Theva No1 features a 1" TNF Al/Mg inverted dome Tweeter and 1 x 6.5" Slatefiber Woofer with a Crossover frequency at 3000 Hz. 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
Theva No1 has a frequency range of 58-28kHz whereas Q350 has a frequency range of 63-28k Hz. With a minimum frequency of 58Hz, the Theva No1 can go significantly deeper on the low side and provide stronger bass compared to the Q350's min frequency of 63Hz.
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
Theva No1 and Q350 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Theva No1 sensitivity is rated at 89 dB and the Q350's is at 87 dB. This 2 dB difference makes the Focal Theva No1 a more sensitive speaker compared to KEF Q350, 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.
Both handle the same maximum of 120 watts RMS, though Theva No1 is rated 25-120 watts and Q350 10-120 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
Theva No1 features Binding post posts which make bi-amping or bi-wiring possible. Q350 has a Post which doesn't feature bi-amping/bi-wiring.
Focal Theva No1's Binding post terminals allows Bi-amping or bi-wiring
KEF Q350's Post terminals
Cabinet Type and Port Position
Both Theva No1 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
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 Focal Theva No1's and KEF Q350's external dimensions. Focal Theva No1 has external dimensions of 391.0 x 213.0 x 261.0mm (153/8 x 83/8 x 101/4) 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 3mm narrower and 33mm shorter than Focal Theva No1 but it is also 45mm deeper.
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 Focal Theva No1 is approximately 555.9cm2 / 86.2inch2 and base area of the KEF Q350 is approximately 642.6cm2 / 99.6inch2. The Theva No1 requires 13% less surface area than the Q350 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 Focal Theva No1 weighs 6.82kg / 15lbs and the KEF Q350 weighs 7.60kg / 16.7lbs. This makes the Q350 11% heavier than the Theva No1.
Here is a comparison of how Theva No1 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 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
 Sensitivity |
89 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Minimum Impedance |
4.6 ohms
vs
3.7 ohms
|
Very low impedance levels puts more pressure on amplifier |
 Low Frequency Response |
58 Hz
vs
63 Hz
|
Generates deeper bass |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Base Surface Area |
555cm2
vs
642cm2
|
Takes less floor space |
 Height |
358mm
vs
391mm
|
Easier to fit in smaller spaces |
 Price per pair* |
750USD
vs
998USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Focal Theva No1 |
KEF Q350 |
| Brand |
Focal |
KEF |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-120 watts |
10-120 watts |
| Sensitivity |
89 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
4.6 ohms |
3.7 ohms |
| Frequency Response |
58-28kHz |
63-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Slatefiber |
Aluminum |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
inverted dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
3000 Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
391.0mm (15.4") |
358.0mm (14.1") |
| Width |
213.0mm (8.4") |
210.0mm (8.3") |
| Depth |
261.0mm (10.3") |
306.0mm (12") |
| Weight |
6.82kg (15lbs) |
7.60kg (16.7lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF/Vinyl-wrapped |
| Available Colors |
Black High Gloss,Dark Wood,Light Wood |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
n/a |
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 |
A generation apart: Focal Theva No1 is the newer design, against a 2016 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 | Focal Theva No1 digs deeper - 58Hz against 63Hz. A subwoofer would even that out. |
| Amplifier needs | A | Focal Theva No1 is more sensitive (89dB vs 87dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (120W vs 120W). |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | A | Focal Theva No1: bi-amping. |
| Price | B | KEF Q350 is cheaper - $750 against $998, about 25% less. |
A Focal Theva No1 B KEF Q350
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?
Focal Theva No1 leads across most of the measured areas for a fairly modest premium, which makes it the easier pick if the budget stretches. KEF Q350 is the one to take if it does not. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 63Hz anyway, which makes the cheaper KEF Q350 much easier to justify. If your amplifier is modest, vintage or valve-based, Focal Theva No1 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.