In this review, we will be comparing 4305P and LSX II, two Powered Bookshelf speakers from JBL and KEF. Being Powered speakers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them.
Let's have a brief look at the main features
of JBL 4305P and KEF LSX II first before getting into our more
detailed comparison.
JBL 4305P Key Specs
- 2-way Design
- 300-watt RMS Integrated Amplifier
- 1" Horn-Loaded Tweeter
- 5.25" Pulp Woofer
- 45-25k Hz Frequency Response
- 24-bit Max Depth / 192kHz Max Sample Rate
- Built-in 5.1 Bluetooth
- App Control Feature
- Weight:6.60kg
- Dimensions (H x W x D): 336.0" x 8.3125" x 11.3125"( 336mm x 210mm x 223.3mm )
KEF LSX II Key Specs
- 2-way Design
- 200-watt RMS Integrated Amplifier
- 11th Generation Uni-Q Driver
- 0.75" Hard-Dome Tweeter
- 4.5" Magnesium/Aluminium alloy Woofer
- 54-28k Hz Frequency Response
- 24-bit Max Depth / 384 kHz Max Sample Rate
- Built-in 4.2 Bluetooth
- App Control Feature
- Weight:3.60kg
- Dimensions (H x W x D): 240.0" x 6.1" x 7.1"( 240 × 155 × 180 mm )
In the following sections, we will get into more detail in order to better understand how the JBL 4305P and KEF LSX II 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 4305P and LSX II are 2-way speakers.
| Driver |
JBL 4305P |
KEF LSX II |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
0.75-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 4.5-inch
|
4305P features a 1" Teonex Horn-Loaded Tweeter and 1 x 5.25" Pulp Woofer with a Crossover frequency at 1750 Hz. On the other hand, the LSX II features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4.5" Magnesium/Aluminium alloy Woofer .
Frequency Response
4305P has a frequency range of 45-25k Hz whereas LSX II has a frequency range of 54-28k Hz. With a minimum frequency of 45Hz, the 4305P can go significantly deeper on the low side and provide stronger bass compared to the LSX II's min frequency of 54Hz.
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.
Cabinet Type and Port Position
4305P has a front firing port whereas LSX II has a rear firing ports. JBL 4305P's front-firing port gives more flexibility in placement in regards to proximity to walls compared to KEF LSX II with its rear-firing port.
KEF LSX II Port
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 JBL 4305P's and KEF LSX II's external dimensions. JBL 4305P has external dimensions of 336mm x 210mm x 223.3mm ( 13.3125inch x 8.3125inch x 11.3125inch ) whereas KEF LSX II has external dimensions of 240 × 155 × 180 mm ( 9.5 × 6.1 × 7.1 inch) .
JBL 4305P is clearly the larger of the two speakers. Its body is 55mm wider, 96mm taller and 43mm deeper than KEF LSX II.
Below you can see the front view size comparison of JBL 4305P and KEF LSX II in scale.
Comparison image of JBL 4305P and KEF LSX II 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 JBL 4305P is approximately 468.0cm2 / 72.5inch2 and base area of the KEF LSX II is approximately 279.0cm2 / 43.2inch2. The 4305P requires 68% more surface area than the LSX II which gives it a small disadvantage 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 JBL 4305P and KEF LSX II 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 JBL 4305P weighs 6.60kg / 14.5lbs and the KEF LSX II weighs 3.60kg / 7.9lbs. This makes the 4305P 83% heavier than the LSX II.
Here is a comparison of how 4305P and LSX II's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of JBL 4305P?
Here are the items that are included inside the box of 4305P:
2 Powered speakers2 GrillesTwo 69-inch AC power cords10-feet CAT5e cableRemote control2 AAA batteries8 Self-adhesive feetOwner-feets ManualImportant Safety Instructions
What's in the Box of KEF LSX II?
Here are the items that come with the LSX II:
2 Wireless powered speakersTwo 6.5-feet AC power cords10-feet Cat-6 interconnect speaker cableRemote control2 AAA batteries Quick Start Guide Important Safety Information Warranty Information Maintenance Guide
 Woofer Size |
5.25 inches
vs
4.5 inches
|
Larger woofer |
|
Low Frequency Response |
45 Hz
vs
54 Hz
|
Generates deeper bass |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 High Frequency Response |
28k Hz
vs
25k Hz
|
Generates higher frequency |
 Height |
240mm
vs
336mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
279cm2
vs
468cm2
|
Takes less floor space |
 Price per pair* |
1299USD
vs
2200USD
|
costs less (*prices may change depending on the seller, location and time) |
 HDMI Input |
ARC
vs
No
|
Connect HDMI sources directly |
| General |
JBL 4305P |
KEF LSX II |
| Brand |
JBL |
KEF |
| Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
| Frequency Response |
45-25k Hz |
54-28k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
200-watt RMS |
| Max Bit Depth |
24-bit |
24-bit |
| Max Sample Rate |
192kHz |
384 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4.5" |
| Woofer Composition |
Pulp |
Magnesium/Aluminium alloy |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1" |
0.75" |
| Tweeter Type |
Horn-Loaded |
Hard-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1750 Hz |
n/a |
| Firing Direction |
front |
rear |
Physical Specs |
|
|
| Height |
336.0mm (13.2") |
240.0mm (9.4") |
| Width |
210.0mm (8.3") |
155.0mm (6.1") |
| Depth |
223.0mm (8.8") |
180.0mm (7.1") |
| Weight |
6.60kg (14.5lbs) |
3.60kg (7.9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
3/4-inch MDF with real wood veneer |
n/a |
| Available Colors |
Satin Walnut, Black Walnut |
Carbon Black, Mineral White, Cobalt Blue, Lava Red, and Soundwave |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm |
3.5mm |
| USB Port |
USB-B |
USB-C (connects to your computer) |
| Phone Input |
No |
No |
| Subwoofer Output |
mono-RCA |
Wired |
| Digital Input |
Optical |
Optical |
| HDMI Input |
No |
ARC |
| Headphone Jack |
No |
No |
| Ethernet Port |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5yr drivers/2 yr amp |
1 Year |
| Labor Warranty |
5yr drivers/2 yr amp |
1 Year |