In this review, we will be comparing M30.3 XD2 and M40.5 XD2, two Passive Bookshelf speakers by Harbeth.
Let's have a brief look at the main features
of Harbeth M30.3 XD2 and Harbeth M40.5 XD2 first before getting into our more
detailed comparison.
| Key Specs | Harbeth M30.3 XD2 | Harbeth M40.5 XD2 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 1" Dome | 1" Dome |
|---|
| Midrange | — | 8" |
|---|
| Woofer | 8" RADIAL | 12" RADIAL |
|---|
| Frequency response | 50-20k Hz | 35-20k Hz |
|---|
| Sensitivity | 85 dB | 86 dB |
|---|
| Impedance | 6 ohms | 6 ohms |
|---|
| Power range | 25-150 watts | 35-650 watts |
|---|
| Weight | 11.60kg / 25.5lbs | 38.00kg / 83.6lbs |
|---|
| Dimensions (H x W x D) | 18-1/8" x 10-7/8" x 10-13/16"
460.0 x 277.0 x 275.0mm | 29-1/2" x 17" x 15-1/4"
750.0 x 432.0 x 388.0mm |
|---|
M30.3 XD2 and M40.5 XD2 are members of Harbeth's XD2 series of speakers. Below you can find the loudspeakers from this series.
Harbeth XD2 Series
History
What size room are the Harbeth M30.3 XD2 and Harbeth M40.5 XD2 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* |
Harbeth M30.3 XD2 |
Harbeth M40.5 XD2 |
| Near-field |
Average |
Bad |
| Small Room |
Good |
Poor |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Good |
| Very Large Room |
Bad |
Average |
(* 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
One of the fundamental differences between these two speakers is that M30.3 XD2 is a 2-way design whereas the M40.5 XD2 is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
Harbeth M30.3 XD2Harbeth M40.5 XD2
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Harbeth M30.3 XD2 |
Harbeth M40.5 XD2 |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 8-inch |
|
Woofer
|
1 x 8-inch
|
1 x 12-inch
|
M30.3 XD2 features a 1" Ferrofluid-cooled dome Dome Tweeter and 1 x 8" RADIAL Woofer. On the other hand, the M40.5 XD2 features a 1" Ferrofluid-cooled dome Dome Tweeter, a 8" Midrange and 1 x 12" RADIAL Woofer.
Frequency Response
M30.3 XD2 has a frequency range of 50-20k Hz whereas M40.5 XD2 has a frequency range of 35-20k Hz. With a minimum frequency of 35Hz, the M40.5 XD2 can go significantly deeper on the low side and provide stronger bass compared to the M30.3 XD2's min frequency of 50Hz.
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
M30.3 XD2 and M40.5 XD2 have the same Impedance of 6 ohms but where they differ is the sensitivity levels. M30.3 XD2 sensitivity is rated at 85 dB and the M40.5 XD2's is at 86 dB. This 1 dB difference makes the Harbeth M40.5 XD2 a more sensitive speaker compared to Harbeth M30.3 XD2, 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.
M40.5 XD2 can handle a max power of 650 watts RMS, whereas M30.3 XD2 has a max power handling value of 150 watts RMS, 500 watts less than the M40.5 XD2.
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
M30.3 XD2 features Binding post type posts and M40.5 XD2 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
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 Harbeth M30.3 XD2's and Harbeth M40.5 XD2's external dimensions. Harbeth M30.3 XD2 has external dimensions of 460.0 x 277.0 x 275.0mm (18-1/8 x 10-7/8 x 10-13/16inch) whereas Harbeth M40.5 XD2 has external dimensions of 750.0 x 432.0 x 388.0mm (29-1/2 x 17 x 15-1/4inch).
Harbeth M40.5 XD2 is clearly the larger of the two speakers. Its body is 155mm wider, 290mm taller and 113mm deeper than Harbeth M30.3 XD2.
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 Harbeth M30.3 XD2 is approximately 761.8cm2 / 118.1inch2 and base area of the Harbeth M40.5 XD2 is approximately 1676.2cm2 / 259.8inch2. The M30.3 XD2 requires 55% less surface area than the M40.5 XD2 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 Harbeth M30.3 XD2 weighs 11.60kg / 25.5lbs and the Harbeth M40.5 XD2 weighs 38.00kg / 83.6lbs. This makes the M40.5 XD2 228% heavier than the M30.3 XD2.
Here is a comparison of how M30.3 XD2 and M40.5 XD2's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
 Height |
460mm
vs
750mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
761cm2
vs
1676cm2
|
Takes less floor space |
 Price per pair* |
6290USD
vs
21990USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
650 watts
vs
150 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
86 dB
vs
85 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
|
Low Frequency Response |
35 Hz
vs
50 Hz
|
Generates deeper bass |
| General |
Harbeth M30.3 XD2 |
Harbeth M40.5 XD2 |
| Brand |
Harbeth |
Harbeth |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-150 watts |
35-650 watts |
| Sensitivity |
85 dB |
86 dB |
| Impedance |
6 ohms |
6 ohms |
| Frequency Response |
50-20k Hz |
35-20k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
RADIAL |
RADIAL |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
8" |
Physical Specs |
|
|
| Height |
460.0mm (18.1") |
750.0mm (29.5") |
| Width |
277.0mm (10.9") |
432.0mm (17") |
| Depth |
275.0mm (10.8") |
388.0mm (15.3") |
| Weight |
11.60kg (25.5lbs) |
38.00kg (83.6lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Mounting Bracket |
|
|
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
Siblings in Harbeth's XD2 series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass |
B |
Harbeth M40.5 XD2 digs deeper - 35Hz against 50Hz. |
| Amplifier needs |
evenly matched |
Similar sensitivity (85dB vs 86dB) - both want much the same power. |
| Headroom |
B |
Harbeth M40.5 XD2 takes more power (650W vs 150W) - more in hand in a big room. |
| Size |
depends |
Harbeth M30.3 XD2 is easier to place; Harbeth M40.5 XD2 is bigger, which usually goes with fuller bass. Your room decides. |
| Price |
A |
Harbeth M30.3 XD2 is cheaper - $6,290 against $21,990, about 71% less; arguably a different class. |
A Harbeth M30.3 XD2
B Harbeth M40.5 XD2
depends neither is better in the abstract - it turns on your room, placement 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: Harbeth M40.5 XD2 measures better, Harbeth M30.3 XD2 costs about 71% 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 50Hz anyway, which makes the cheaper Harbeth M30.3 XD2 much easier to justify. Match it to your room: we rate Harbeth M30.3 XD2 the better fit for near-field listening and a small room, and Harbeth M40.5 XD2 for a large room and a very large room.
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.