In this review, we will be comparing M20 HD and Alpha AM5, two Powered Bookshelf speakers from Q Acoustics and PSB. 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 Q Acoustics M20 HD and PSB Alpha AM5 first before getting into our more
detailed comparison.
| Key Specs | Q Acoustics M20 HD | PSB Alpha AM5 |
|---|
| Brand | Q Acoustics
United Kingdom · founded 2006 | PSB
Canada · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Built-in amplifier | 128-watt RMS | 100-watt RMS |
|---|
| Tweeter | 0.875" Dome | 0.75" Hard-Dome |
|---|
| Woofer | 5" | 5.25" Polypropylene |
|---|
| Frequency response | 55-22k Hz | 55-20k Hz |
|---|
| Max depth / sample rate | 24-bit / 192 kHz | 24-bit / 48 kHz |
|---|
| Bluetooth | Built-in 5.0 | Built-in 5.0 |
|---|
| Weight | 5.10kg / 11.2lbs | 9.75kg / 21.5lbs |
|---|
| Dimensions (H x W x D) | 10-15/16" x 6-11/16" x 12-3/16"
278.0 x 170.0 x 310.0mm | 11.5" x 6.75" x 11"
292.1 x 171.5 x 279.4mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both M20 HD and Alpha AM5 are 2-way speakers.
Q Acoustics M20 HDPSB Alpha AM5
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Q Acoustics M20 HD |
PSB Alpha AM5 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.875-inch
|
0.75-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
1 x 5.25-inch
|
M20 HD features a 0.875" Dome Tweeter and 1 x 5" Woofer. On the other hand, the Alpha AM5 features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 5.25" Polypropylene Woofer.
Frequency Response
M20 HD has a frequency range of 55-22k Hz whereas Alpha AM5 has a frequency range of 55-20k Hz.
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
Both M20 HD and Alpha AM5 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 Q Acoustics M20 HD's and PSB Alpha AM5's external dimensions. Q Acoustics M20 HD has external dimensions of 278.0 x 170.0 x 310.0mm (10-15/16 x 6-11/16 x 12-3/16inch) whereas PSB Alpha AM5 has external dimensions of 292.1 x 171.5 x 279.4mm (11.5 x 6.75 x 11inch).
Q Acoustics M20 HD is 1.5mm narrower and 14.1mm shorter than PSB Alpha AM5 but it is also 30.6mm 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 Q Acoustics M20 HD is approximately 527.0cm2 / 81.7inch2 and base area of the PSB Alpha AM5 is approximately 479.2cm2 / 74.3inch2. The M20 HD requires 10% more surface area than the Alpha AM5 which gives it a small disadvantage 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 Q Acoustics M20 HD weighs 5.10kg / 11.2lbs and the PSB Alpha AM5 weighs 9.75kg / 21.5lbs. This makes the Alpha AM5 91% heavier than the M20 HD.
Here is a comparison of how M20 HD and Alpha AM5's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Q Acoustics M20 HD?
Here are the items that are included inside the box of M20 HD:
- Powered speaker
- Passive speaker
- 6-feet AC power cord
- Remote control
- 2 AAA batteries
- 13-feet Speaker wire
- 59-inch Optical digital cable
- 2 Foam port plugs
- Owners Manual
What's in the Box of PSB Alpha AM5?
Here are the items that come with the Alpha AM5:
- 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
 High Frequency Response |
22k Hz
vs
20k Hz
|
Generates higher frequency |
 Height |
278mm
vs
292mm
|
Easier to fit in smaller spaces |
 USB Port |
USB-B
vs
No
|
USB port adds flexibility |
 RCA Connection |
Yes
vs
No
|
Connection via RCA input |
 Subwoofer Output |
mono-RCA
vs
No
|
Pair your speakers with external subwoofer |
 Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
 Base Surface Area |
479cm2
vs
527cm2
|
Takes less floor space |
|
USB Port |
microUSB
vs
No
|
USB port adds flexibility |
 Phono Input |
Yes
vs
No
|
Connect your turntable directly |
| General |
Q Acoustics M20 HD Wireless Music System |
PSB Alpha AM5 |
| Brand |
Q Acoustics |
PSB |
| Speaker Type |
Powered stereo speakers |
Powered Stereo Speakers |
| Frequency Response |
55-22k Hz |
55-20k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
128-watt RMS |
100-watt RMS |
| Max Bit Depth |
24-bit |
24-bit |
| Max Sample Rate |
192 kHz |
48 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5" |
5.25" |
| Woofer Composition |
|
Polypropylene |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
0.875" |
0.75" |
| Tweeter Type |
Dome |
Hard-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
278.0mm (10.9") |
292.1mm (11.5") |
| Width |
170.0mm (6.7") |
171.5mm (6.8") |
| Depth |
310.0mm (12.2") |
279.4mm (11") |
| Weight |
5.10kg (11.2lbs) |
9.75kg (21.5lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF, Wood-grain vinyl |
| Available Colors |
Black, White, Walnut |
Matte Black, Matte White |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm, Stereo RCA |
3.5mm |
| USB Port |
USB-B |
microUSB |
| Phone Input |
No |
Yes |
| Subwoofer Output |
mono-RCA |
No |
| Digital Input |
Optical |
Optical |
| HDMI Input |
No |
No |
| Headphone Jack |
No |
No |
| Ethernet Port |
No |
No |
Other |
|
|
| Parts Warranty |
2 Years |
1 Year |
| Labor Warranty |
2 Years |
1 Year |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your sources and what you listen to.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (55Hz vs 55Hz). |
| Built-in power | A | Q Acoustics M20 HD has the bigger amplifier (128W vs 100W RMS). |
| Connections | depends | Q Acoustics M20 HD adds streaming; PSB Alpha AM5 adds phono. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | A | Q Acoustics M20 HD: a sub output. |
| Price | evenly matched | Much the same money ($599 vs $599 a pair). |
A Q Acoustics M20 HD B PSB Alpha AM5
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?
Q Acoustics M20 HD has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does.
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.