In this review, we will be comparing Alpha AM3 and LSX, two Powered Bookshelf speakers from PSB 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 PSB Alpha AM3 and KEF LSX first before getting into our more
detailed comparison.
In the following sections, we will get into more detail in order to better understand how the PSB Alpha AM3 and KEF LSX 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 Alpha AM3 and LSX are 2-way speakers.
Driver |
PSB Alpha AM3 |
KEF LSX |
Driver Setup
|
2-way
|
2-way
|
Tweeter
|
0.75-inch
|
0.75-inch
|
Midrange
|
- |
- |
Woofer
|
1 x 4-inch
|
1 x 4.5-inch
|
Alpha AM3 features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4" Polypropylene Woofer . On the other hand, the LSX features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4.5" Magnesium/Aluminium alloy Woofer .
Frequency Response
Alpha AM3 has a frequency range of 56-20k Hz whereas LSX has a frequency range of 59-28k Hz. With a minimum frequency of 56Hz, the Alpha AM3 can go slightly deeper then the LSX's min frequency of 59Hz.
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
Both Alpha AM3 and LSX 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 PSB Alpha AM3's and KEF LSX's external dimensions. PSB Alpha AM3 has external dimensions of 220.7 x 131.8 x 206.4mm ( 8.6875 x 5.1875 x 8.125inch) whereas KEF LSX has external dimensions of 239.7 x 155.6 x 180mm ( 9.4375 x 6.125 x 7.1inch) .
PSB Alpha AM3 is 23.8mm narrower and 19mm shorter than KEF LSX but it is also 26.4mm deeper.
Below you can see the front view size comparison of PSB Alpha AM3 and KEF LSX in scale.
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 PSB Alpha AM3 is approximately 272.0cm2 / 42.2inch2 and base area of the KEF LSX is approximately 365.7cm2 / 56.7inch2. The Alpha AM3 requires 26% less surface area than the LSX 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:
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 PSB Alpha AM3 weighs 4.50kg / 9.9lbs and the KEF LSX weighs 3.50kg / 7.7lbs. This makes the Alpha AM3 29% heavier than the LSX.
Here is a comparison of how Alpha AM3 and LSX's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of PSB Alpha AM3?
Here are the items that are included inside the box of Alpha AM3:
Powered speaker Passive speaker 2 Grilles AC power adapter (attached 45-inch DC cord) 4-feet AC power cord Remote control (PSR-1) 2 AAA batteries 8-feet Speaker cable 58-inch Stereo minijack cable 8 Self-adhesive rubber feet Connection Diagram Warranty Card
What's in the Box of KEF LSX?
Here are the items that come with the LSX:
2 Powered wireless audio speakerTwo 6.5-feet AC power cords10-feet Ethernet cableRemote control (CR2032 3V battery pre-installed)Maintenance GuideSpecificationsWarranty InformationImportant Safety Information
Low Frequency Response |
56 Hz
vs
59 Hz
|
Generates deeper bass |
Height |
220mm
vs
239mm
|
Easier to fit in smaller spaces |
Base Surface Area |
272cm2 (131x206mm)
vs
365cm2 (155x180mm)
|
Takes less floor space |
Price per pair* |
449USD
vs
1250USD
|
costs less (*prices may change depending on the seller, location and time) |
Phono Input |
Yes
vs
No
|
Connect your turntable directly |
Woofer Size |
4.5 inches
vs
4 inches
|
Larger woofer |
High Frequency Response |
28k Hz
vs
20k Hz
|
Generates higher frequency |
App-Based Control |
Apple iOS, Android
vs
None
|
Control the speaker via an app |
Ethernet Connection |
Yes
vs
No
|
High quality streaming over Ethernet |
USB Port |
Charge only
vs
No
|
USB port adds flexibility |
Subwoofer Output |
Wired
vs
No
|
Pair your speakers with external subwoofer |
General |
PSB Alpha AM3 |
KEF LSX |
Brand |
PSB |
KEF |
Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
Frequency Response |
56-20k Hz |
59-28k Hz |
Amplifier |
|
|
Watts RMS (Continuous) |
70-watt RMS |
200-watt RMS |
Max Bit Depth |
24-bit |
24-bit |
Max Sample Rate |
48 kHz |
96 kHz |
Drivers |
|
|
Woofer Quantity |
1 |
1 |
Woofer Size |
4" |
4.5" |
Woofer Composition |
Polypropylene |
Magnesium/Aluminium alloy |
Woofer Surround Material |
Rubber |
Rubber |
Tweeter Size |
0.75" |
0.75" |
Tweeter Type |
Hard-Dome |
Hard-Dome |
Aimable Tweeter |
No |
No |
Midrange Driver |
No |
No |
Firing Direction |
rear |
rear |
Physical Specs |
|
|
Height |
220.7mm (8.7") |
239.7mm (9.4") |
Width |
131.8mm (5.2") |
155.6mm (6.1") |
Depth |
206.4mm (8.1") |
180.0mm (7.1") |
Weight |
4.50kg (9.9lbs) |
3.50kg (7.7lbs) |
Enclosure |
Bass Reflex |
Bass Reflex |
Finish |
MDF, Wood-grain vinyl |
n/a |
Available Colors |
Matte Black, Matte White |
Black, Olive Green, Gloss White |
Mounting Bracket |
No |
No |
Grille |
Yes |
n/a |
Moisture Resistancy |
No |
No |
Connections |
|
|
Aux Inputs |
3.5mm |
3.5mm |
USB Port |
microUSB |
Charge only |
Phone Input |
Yes |
No |
Subwoofer Output |
No |
Wired |
Digital Input |
Optical |
Optical |
HDMI Input |
No |
No |
Headphone Jack |
No |
No |
Ethernet Port |
No |
Yes |
Other |
|
|
Parts Warranty |
1 Year |
1 Year |
Labor Warranty |
1 Year |
1 Year |