In this review, we will be comparing LSX II and HD3, two Powered Bookshelf speakers from KEF and Audioengine. 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 KEF LSX II and Audioengine HD3 first before getting into our more
detailed comparison.
| Key Specs | KEF LSX II | Audioengine HD3 |
|---|
| Brand | KEF
United Kingdom · founded 1961 | Audioengine
United States · founded 2005 |
|---|
| Design | 2-way | 2-way |
|---|
| Built-in amplifier | 200-watt RMS | 30-watt RMS (60-watt peak) |
|---|
| Uni-Q driver | 11th Generation Uni-Q | — |
|---|
| Tweeter | 0.75" Hard-Dome | 0.75" Soft-Dome |
|---|
| Woofer | 4.5" Magnesium/Aluminium alloy | 2.75" Kevlar/Glass-Aramid Composite |
|---|
| Frequency response | 54-28k Hz | 65-22k Hz |
|---|
| Max depth / sample rate | 24-bit / 384 kHz | 24-bit / 48 kHz |
|---|
| Bluetooth | Built-in 4.2 | Built-in 5.0 |
|---|
| App control | Yes | — |
|---|
| Weight | 3.60kg / 7.9lbs | 1.55kg / 3.4lbs |
|---|
| Dimensions (H x W x D) | 9.5" x 6.1" x 7.1"
240 × 155 × 180 mm | 7" x 4.25" x 5-1/2"
177.8 x 108.0 x 139.7mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both LSX II and HD3 are 2-way speakers.
KEF LSX IIAudioengine HD3
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
KEF LSX II |
Audioengine HD3 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.75-inch
|
0.75-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4.5-inch
|
1 x 2.75-inch
|
LSX II features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4.5" Magnesium/Aluminium alloy Woofer. On the other hand, the HD3 features a 0.75" Silk Soft-Dome Tweeter and 1 x 2.75" Kevlar/Glass-Aramid Composite Woofer.
Frequency Response
LSX II has a frequency range of 54-28k Hz whereas HD3 has a frequency range of 65-22k Hz. With a minimum frequency of 54Hz, the LSX II can go significantly deeper on the low side and provide stronger bass compared to the HD3's min frequency of 65Hz.
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.
Cabinet Type and Port Position
LSX II has a rear firing port whereas HD3 has a front firing ports. Audioengine HD3'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
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 KEF LSX II's and Audioengine HD3's external dimensions. KEF LSX II has external dimensions of 240 × 155 × 180 mm (9.5 × 6.1 × 7.1 inch) whereas Audioengine HD3 has external dimensions of 177.8 x 108.0 x 139.7mm (9.125 x 4.25 x 7.25inch).
KEF LSX II is clearly the larger of the two speakers. Its body is 47mm wider, 62.2mm taller and 40.3mm deeper than Audioengine HD3.
Below you can see the front view size comparison of KEF LSX II and Audioengine HD3 in scale.
Comparison image of KEF LSX II and Audioengine HD3 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 KEF LSX II is approximately 279.0cm2 / 43.2inch2 and base area of the Audioengine HD3 is approximately 150.9cm2 / 23.4inch2. The LSX II requires 85% more surface area than the HD3 which gives it a small disadvantage 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 KEF LSX II and Audioengine HD3 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 KEF LSX II weighs 3.60kg / 7.9lbs and the Audioengine HD3 weighs 1.55kg / 3.4lbs. This makes the LSX II 132% heavier than the HD3.
Here is a comparison of how LSX II and HD3's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of KEF LSX II?
Here are the items that are included inside the box of LSX II:
- 2 Wireless powered speakers
- Two 6.5-feet AC power cords
- 10-feet Cat-6 interconnect speaker cable
- Remote control
- 2 AAA batteries
- Quick Start Guide
- Important Safety Information
- Warranty Information
- Maintenance Guide
What's in the Box of Audioengine HD3?
Here are the items that come with the HD3:
- Powered speaker
- Passive speaker
- 2 Grilles (pre-installed)
- AC power supply (attached 6-feet DC cord)
- 6-feet AC power cord
- Bluetooth antenna
- 5-feet microUSB-to-USB cable
- 6.5-feet Speaker cable (banana connectors on each end)
- 5-feet Stereo minijack cable
- 2 Microfiber speaker bags
- MIcrofiber cable bag
- Quickstart Guide
- Product Line Brochure
 Woofer Size |
4.5 inches
vs
2.75 inches
|
Larger woofer |
|
Low Frequency Response |
54 Hz
vs
65 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
22k 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 |
USB-C (connects to your computer)
vs
No
|
USB port adds flexibility |
 Digital Input |
Optical
vs
No
|
Connect digital inputs directly |
 HDMI Input |
ARC
vs
No
|
Connect HDMI sources directly |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Height |
177mm
vs
240mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
150cm2
vs
279cm2
|
Takes less floor space |
 Price per pair* |
349USD
vs
1299USD
|
costs less (*prices may change depending on the seller, location and time) |
 RCA Connection |
Yes
vs
No
|
Connection via RCA input |
 Headphone Output |
3.5mm
vs
No
|
Connect your headphone |
| General |
KEF LSX II |
Audioengine HD3 |
| Brand |
KEF |
Audioengine |
| Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
| Frequency Response |
54-28k Hz |
65-22k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
200-watt RMS |
30-watt RMS |
| Watts Peak (Max) |
n/a |
60-watt RMS |
| Max Bit Depth |
24-bit |
24-bit |
| Max Sample Rate |
384 kHz |
48 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
4.5" |
2.75" |
| Woofer Composition |
Magnesium/Aluminium alloy |
Kevlar/Glass-Aramid Composite |
| Woofer Surround Material |
Rubber |
n/a |
| Tweeter Size |
0.75" |
0.75" |
| Tweeter Type |
Hard-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
rear |
front |
Physical Specs |
|
|
| Height |
240.0mm (9.4") |
177.8mm (7") |
| Width |
155.0mm (6.1") |
108.0mm (4.3") |
| Depth |
180.0mm (7.1") |
139.7mm (5.5") |
| Weight |
3.60kg (7.9lbs) |
1.55kg (3.4lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Carbon Black, Mineral White, Cobalt Blue, Lava Red, and Soundwave |
Black, Walnut, White |
| Mounting Bracket |
No |
No |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm |
3.5mm, RCA |
| USB Port |
USB-C (connects to your computer) |
microUSB |
| Phone Input |
No |
No |
| Subwoofer Output |
Wired |
Wired |
| Digital Input |
Optical |
No |
| HDMI Input |
ARC |
No |
| Headphone Jack |
No |
3.5mm |
| Ethernet Port |
Yes |
No |
Other |
|
|
| Parts Warranty |
1 Year |
3 Years |
| Labor Warranty |
1 Year |
3 Years |
These sit in different price classes - KEF LSX II costs roughly 3.7x what Audioengine HD3 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 | A | KEF LSX II digs deeper - 54Hz against 65Hz. |
| Built-in power | A | KEF LSX II has the bigger amplifier (200W vs 30W RMS). |
| Connections | A | KEF LSX II adds Wi-Fi, streaming, HDMI and digital inputs. |
| Size | depends | Audioengine HD3 is easier to place; KEF LSX II is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | KEF LSX II: a sub output; Audioengine HD3: a sub output. KEF LSX II sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | B | Audioengine HD3 is cheaper - $349 against $1,299, about 73% less; arguably a different class. |
A KEF LSX II B Audioengine HD3
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 LSX II measures better, Audioengine HD3 costs about about 3.7x 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 65Hz anyway, which makes the cheaper Audioengine HD3 much easier to justify. In a large or open-plan room, KEF LSX II has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Audioengine HD3 is the easier speaker to get right.
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.