In this review, we will be comparing SX-70 and Bronze C150, two Center Channel speakers from Cambridge Audio and Monitor Audio.
Let's have a brief look at the main features
of Cambridge Audio SX-70 and Monitor Audio Bronze C150 first before getting into our more
detailed comparison.
| Key Specs | Cambridge Audio SX-70 | Monitor Audio Bronze C150 |
|---|
| Brand | Cambridge Audio
United Kingdom · founded 1968 | Monitor Audio
United Kingdom · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" dome | 1" vented dome with waveguide |
|---|
| Woofer | 2 x 4" treated-paper | 5.25" aluminum |
|---|
| Frequency response | 65-22k Hz | 66-30k Hz |
|---|
| Sensitivity | 85 dB | 88 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 10-100 watts | 30-120 watts |
|---|
| Weight | 4.00kg / 8.8lbs | 7.01kg / 15.4lbs |
|---|
| Dimensions (H x W x D) | 5-7/16" x 14-1/4" x 9-3/4"
139.0 x 362.0 x 248.0mm | 6-9/16" x 17-13/16" x 8-15/16"
167.0 x 453.0 x 228.0mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both SX-70 and Bronze C150 are 2-way speakers.
Cambridge Audio SX-70Monitor Audio Bronze C150
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Cambridge Audio SX-70 |
Monitor Audio Bronze C150 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4-inch
|
1 x 5.25-inch
|
SX-70 features a 1" Silk dome Tweeter and 2 x 4" treated-paper Woofer. On the other hand, the Bronze C150 features a 1" aluminum vented dome with waveguide Tweeter and 1 x 5.25" aluminum Woofer.
Frequency Response
SX-70 has a frequency range of 65-22k Hz whereas Bronze C150 has a frequency range of 66-30k Hz. With a minimum frequency of 65Hz, the SX-70 can go slightly deeper then the Bronze C150's min frequency of 66Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Center Channel class in our database.
Low Frequency
Center Channel 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
SX-70 and Bronze C150 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. SX-70 sensitivity is rated at 85 dB and the Bronze C150's is at 88 dB. This 3 dB difference makes the Monitor Audio Bronze C150 a more sensitive speaker compared to Cambridge Audio SX-70, hence will play louder with the same amount of watts.
Sensitivity
Center Channel 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.
Bronze C150 can handle a max power of 120 watts RMS, whereas SX-70 has a max power handling value of 100 watts RMS, 20 watts less than the Bronze C150.
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.
Monitor Audio Bronze C150
Input Type and Bi-Amping / Bi-Wiring
SX-70 features Binding post type posts and Bronze C150 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
Monitor Audio Bronze C150'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 Cambridge Audio SX-70's and Monitor Audio Bronze C150's external dimensions. Cambridge Audio SX-70 has external dimensions of 139.0 x 362.0 x 248.0mm (5-7/16 x 14-1/4 x 9-3/4inch) whereas Monitor Audio Bronze C150 has external dimensions of 167.0 x 453.0 x 228.0mm (6-9/16 x 17-13/16 x 8-15/16inch).
Cambridge Audio SX-70 is 91mm narrower and 28mm shorter than Monitor Audio Bronze C150 but it is also 20mm 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.
Monitor Audio Bronze C150 needs about 15% more floor or shelf area. Cambridge Audio SX-70 is 20mm deeper, so it stands that much further out from the wall. Monitor Audio Bronze C150 is 28mm 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 Cambridge Audio SX-70 is approximately 897.8cm2 / 139.2inch2 and base area of the Monitor Audio Bronze C150 is approximately 1032.8cm2 / 160.1inch2. The SX-70 requires 13% less surface area than the Bronze C150 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 Cambridge Audio SX-70 weighs 4.00kg / 8.8lbs and the Monitor Audio Bronze C150 weighs 7.01kg / 15.4lbs. This makes the Bronze C150 75% heavier than the SX-70.
Here is a comparison of how SX-70 and Bronze C150's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
Monitor Audio Bronze C150
What's in the Box of Cambridge Audio SX-70?
Here are the items that are included inside the box of SX-70:
- Center-channel loudspeaker
- Grille
- 4 Self-adhesive rubber feet
- Installation Guide
What's in the Box of Monitor Audio Bronze C150?
Here are the items that come with the Bronze C150:
- Center-channel loudspeaker
- Grille
- 2 Terminal-jumpers (pre-installed)
- 4 Self-adhesive rubber feet
- Hex-key
- Quick Start Guide
- Important Safety Instructions
 Number of Woofers |
2
vs
1
|
More woofers |
|
Low Frequency Response |
65 Hz
vs
66 Hz
|
Generates deeper bass |
 Height |
139mm
vs
167mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
897cm2
vs
1032cm2
|
Takes less floor space |
 Price per pair* |
189USD
vs
395USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
120 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
88 dB
vs
85 dB
|
Play louder with same amount of amplification power |
|
Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
 High Frequency Response |
30k Hz
vs
22k Hz
|
Generates higher frequency |
| General |
Cambridge Audio SX-70 |
Monitor Audio Bronze C150 |
| Brand |
Cambridge Audio |
Monitor Audio |
| Speaker Type |
Center channel speaker (Matte Black) |
Center channel speaker |
| Power Range |
10-100 watts |
30-120 watts |
| Sensitivity |
85 dB |
88 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
65-22k Hz |
66-30k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
4" |
5.25" |
| Woofer Composition |
treated-paper |
aluminum |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
dome |
vented dome with waveguide |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
Physical Specs |
|
|
| Height |
139.0mm (5.5") |
167.0mm (6.6") |
| Width |
362.0mm (14.3") |
453.0mm (17.8") |
| Depth |
248.0mm (9.8") |
228.0mm (9") |
| Weight |
4.00kg (8.8lbs) |
7.01kg (15.4lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Available Colors |
Black |
Walnut |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - Monitor Audio Bronze C150 costs roughly 2.1x what Cambridge Audio SX-70 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 | evenly matched | Much the same reach (65Hz vs 66Hz). |
| Amplifier needs | B | Monitor Audio Bronze C150 is more sensitive (88dB vs 85dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (100W vs 120W). |
| Size | depends | Cambridge Audio SX-70 is easier to place; Monitor Audio Bronze C150 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Monitor Audio Bronze C150 sits in a wider range (11 models), so a matched surround system is easier later. |
| Price | A | Cambridge Audio SX-70 is cheaper - $189 against $395, about 52% less; arguably a different class. |
A Cambridge Audio SX-70 B Monitor Audio Bronze C150
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?
Monitor Audio Bronze C150 is ahead, but only on 1 of the measured areas, and it costs about 109% more. That is a lot of money for a narrow margin on paper - Cambridge Audio SX-70 looks like the sensible buy unless something else about the Monitor Audio Bronze C150 appeals to you. Match it to your room: we rate Cambridge Audio SX-70 the better fit for near-field listening and a small room, and Monitor Audio Bronze C150 for a mid-size room and a large room. If your amplifier is modest, vintage or valve-based, Monitor Audio Bronze C150 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.