In this review, we will be comparing 750 and Sandwich 150, two Passive Bookshelf speakers from Mission and Leak.
Let's have a brief look at the main features
of Mission 750 and Leak Sandwich 150 first before getting into our more
detailed comparison.
| Key Specs | Mission 750 | Leak Sandwich 150 |
|---|
| Brand | Mission
United Kingdom · founded 1977 | Leak
United Kingdom · founded 1934 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1.25" Soft-Dome | 1.2" Dome |
|---|
| Woofer | 5.25" Polypropylene | 6.5" Aluminium-Foamcore Sandwich cone |
|---|
| Frequency response | 48-20k Hz | 44Hz-26kHz |
|---|
| Sensitivity | 86 dB | 86.5 dB |
|---|
| Impedance | 6 ohms | 4 ohms |
|---|
| Power range | 25-100 watts | 25-150 watts |
|---|
| Weight | 9.00kg / 19.8lbs | 12.30kg / 27.1lbs |
|---|
| Dimensions (H x W x D) | 14" x 8-1/2" x 12"
355.0 x 216.0 x 305.0mm | 16.3" x 9.9" x 11.4"
415 x 250 x 290 mm |
|---|
What size room are the Mission 750 and Leak Sandwich 150 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* |
Mission 750 |
Leak Sandwich 150 |
| Near-field |
Good |
Poor |
| Small Room |
Good |
Average |
| Mid-size Room |
Average |
Good |
| Large Room |
Poor |
Average |
| Very Large Room |
No way |
Poor |
(* 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.
Drivers
Both 750 and Sandwich 150 are 2-way speakers.
Mission 750Leak Sandwich 150
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Mission 750 |
Leak Sandwich 150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.25-inch
|
1.2-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 6.5-inch
|
750 features a 1.25" Silk Soft-Dome Tweeter and 1 x 5.25" Polypropylene Woofer with a Crossover frequency at 2.4kHz. On the other hand, the Sandwich 150 features a 1.2" Coated Textile Dome Tweeter and 1 x 6.5" Aluminium-Foamcore Sandwich cone Woofer with a Crossover frequency at 2400Hz.
Frequency Response
750 has a frequency range of 48-20k Hz whereas Sandwich 150 has a frequency range of 44Hz-26kHz. With a minimum frequency of 44Hz, the Sandwich 150 can go slightly deeper then the 750's min frequency of 48Hz.
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
750 is a 6 ohms speaker compared to the Sandwich 150 which has a nominal impedance of 4 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the Sandwich 150 can provide this impedance level.
These two speakers also have different sensitivity levels. 750 sensitivity is rated at 86 dB and the Sandwich 150's is rated at 86.5 dB. This 1 dB difference makes the Leak Sandwich 150 a more sensitive speaker compared to Mission 750, 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.
Sandwich 150 can handle a max power of 150 watts RMS, whereas 750 has a max power handling value of 100 watts RMS, 50 watts less than the Sandwich 150.
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
750 features Binding post type posts and Sandwich 150 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
Leak Sandwich 150's Binding post terminals
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 Mission 750's and Leak Sandwich 150's external dimensions. Mission 750 has external dimensions of 355.0 x 216.0 x 305.0mm (14 x 8-1/2 x 12inch) whereas Leak Sandwich 150 has external dimensions of 415 x 250 x 290 mm (16.3 x 9.9 x 11.4 inch).
Mission 750 is 34mm narrower and 60mm shorter than Leak Sandwich 150 but it is also 15mm deeper.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Leak Sandwich 150 needs about 10% more floor or shelf area. Mission 750 is 15mm deeper, so it stands that much further out from the wall. Leak Sandwich 150 is 60mm taller.
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 Mission 750 is approximately 658.8cm2 / 102.1inch2 and base area of the Leak Sandwich 150 is approximately 725.0cm2 / 112.4inch2. The 750 requires 9% less surface area than the Sandwich 150 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 Mission 750 weighs 9.00kg / 19.8lbs and the Leak Sandwich 150 weighs 12.30kg / 27.1lbs. This makes the Sandwich 150 37% heavier than the 750.
Here is a comparison of how 750 and Sandwich 150's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
 Nominal Impedance |
6 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Height |
355mm
vs
415mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
658cm2
vs
725cm2
|
Takes less floor space |
 Max Input Power |
150 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
87 dB
vs
86 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
44 Hz
vs
48 Hz
|
Generates deeper bass |
 High Frequency Response |
26k Hz
vs
20k Hz
|
Generates higher frequency |
| General |
Mission 750 |
Leak Sandwich 150 |
| Brand |
Mission |
Leak |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-100 watts |
25-150 watts |
| Sensitivity |
86 dB |
86.5 dB |
| Impedance |
6 ohms |
4 ohms |
| Impedance |
4.5 ohms |
n/a |
| Frequency Response |
48-20k Hz |
44Hz-26kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
6.5" |
| Woofer Composition |
Polypropylene |
Aluminium-Foamcore Sandwich cone |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1.25" |
1.2" |
| Tweeter Type |
Soft-Dome |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2.4kHz |
2400Hz |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
355.0mm (14") |
415.0mm (16.3") |
| Width |
216.0mm (8.5") |
250.0mm (9.8") |
| Depth |
305.0mm (12") |
290.0mm (11.4") |
| Weight |
9.00kg (19.8lbs) |
12.30kg (27.1lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
real-wood veneer |
| Available Colors |
n/a |
walnut |
| Mounting Bracket |
|
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
|
|
| Labor Warranty |
|
|
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | B | Leak Sandwich 150 digs deeper - 44Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (86dB vs 87dB) - both want much the same power. |
| Amplifier match | A | Mission 750 is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | B | Leak Sandwich 150 takes more power (150W vs 100W) - more in hand in a big room. |
| Size | depends | Mission 750 is easier to place; Leak Sandwich 150 is bigger, which usually goes with fuller bass. Your room decides. |
| Price | evenly matched | Much the same money ($1,199 vs $1,199 a pair). |
A Mission 750 B Leak Sandwich 150
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?
Leak Sandwich 150 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. Match it to your room: we rate Mission 750 the better fit for near-field listening and a small room, and Leak Sandwich 150 for a mid-size room and a large room. If your amplifier is modest, vintage or valve-based, Mission 750 is the safer partner - the other will want more current or more watts to sound its best.
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.