In this review, we will be comparing Bronze C150 and ES30, two Passive Center Channel speakers from Monitor Audio and Polk Audio.
Let's have a brief look at the main features
of Monitor Audio Bronze C150 and Polk ES30 first before getting into our more
detailed comparison.
| Key Specs | Monitor Audio Bronze C150 | Polk ES30 |
|---|
| Brand | Monitor Audio
United Kingdom · founded 1972 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" vented dome with waveguide | 1" High-res dome |
|---|
| Woofer | 5.25" aluminum | 2 x 5.5" mica-reinforced polypropylene Dynamic Balance |
|---|
| Frequency response | 66-30k Hz | 55-40k Hz |
|---|
| Sensitivity | 88 dB | 89 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 30-120 watts | 20-125 watts |
|---|
| Weight | 7.01kg / 15.4lbs | 8.64kg / 19lbs |
|---|
| Dimensions (H x W x D) | 6-9/16" x 17-13/16" x 8-15/16"
167.0 x 453.0 x 228.0mm | 7-1/2" x 20-1/16" x 10-5/8"
191.0 x 510.0 x 270.0mm |
|---|
What size room are the Monitor Audio Bronze C150 and Polk ES30 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* |
Monitor Audio Bronze C150 |
Polk ES30 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
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 Bronze C150 and ES30 are 2-way speakers.
Monitor Audio Bronze C150Polk ES30
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Monitor Audio Bronze C150 |
Polk ES30 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
2 x 5.5-inch
|
Bronze C150 features a 1" aluminum vented dome with waveguide Tweeter and 1 x 5.25" aluminum Woofer. On the other hand, the ES30 features a 1" Terylene High-res dome Tweeter and 2 x 5.5" mica-reinforced polypropylene Dynamic Balance Woofer.
Frequency Response
Bronze C150 has a frequency range of 66-30k Hz whereas ES30 has a frequency range of 55-40k Hz. With a minimum frequency of 55Hz, the ES30 can go significantly deeper on the low side and provide stronger bass compared to 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
Bronze C150 and ES30 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Bronze C150 sensitivity is rated at 88 dB and the ES30's is at 89 dB. This 1 dB difference makes the Polk ES30 a more sensitive speaker compared to Monitor Audio Bronze C150, 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.
ES30 can handle a max power of 125 watts RMS, whereas Bronze C150 has a max power handling value of 120 watts RMS, 5 watts less than the ES30.
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
Bronze C150 features 5-Way post type posts and ES30 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
Monitor Audio Bronze C150's Binding post terminals
Polk ES30's 5-Way post terminals
Polk ES30 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 Monitor Audio Bronze C150's and Polk ES30's external dimensions. 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) whereas Polk ES30 has external dimensions of 191.0 x 510.0 x 270.0mm (7-1/2 x 20-1/16 x 10-5/8inch).
Polk ES30 is clearly the larger of the two speakers. Its body is 57mm wider, 24mm taller and 42mm deeper than Monitor Audio Bronze C150.
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 Monitor Audio Bronze C150 is approximately 1032.8cm2 / 160.1inch2 and base area of the Polk ES30 is approximately 1377.0cm2 / 213.4inch2. The Bronze C150 requires 25% less surface area than the ES30 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 Monitor Audio Bronze C150 weighs 7.01kg / 15.4lbs and the Polk ES30 weighs 8.64kg / 19lbs. This makes the ES30 23% heavier than the Bronze C150.
Here is a comparison of how Bronze C150 and ES30'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 Monitor Audio Bronze C150?
Here are the items that are included inside the box of Bronze C150:
- Center-channel loudspeaker
- Grille
- 2 Terminal-jumpers (pre-installed)
- 4 Self-adhesive rubber feet
- Hex-key
- Quick Start Guide
- Important Safety Instructions
What's in the Box of Polk ES30?
Here are the items that come with the ES30:
- Center-channel loudspeaker
- Grille (attached)
- 4 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
 Height |
167mm
vs
191mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1032cm2
vs
1377cm2
|
Takes less floor space |
 Max Input Power |
125 watts
vs
120 watts
|
Handle more power from your amplifier |
 Sensitivity |
89 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
5.5 inches
vs
5.25 inches
|
Larger woofer |
|
Number of Woofers |
2
vs
1
|
More woofers |
|
Low Frequency Response |
55 Hz
vs
66 Hz
|
Generates deeper bass |
 High Frequency Response |
40k Hz
vs
30k Hz
|
Generates higher frequency |
 Price per pair* |
299USD
vs
395USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Monitor Audio Bronze C150 |
Polk Audio Signature Elite ES30 |
| Brand |
Monitor Audio |
Polk Audio |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
30-120 watts |
20-125 watts |
| Sensitivity |
88 dB |
89 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
66-30k Hz |
55-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
5.25" |
5.5" |
| Woofer Composition |
aluminum |
mica-reinforced polypropylene Dynamic Balance |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
vented dome with waveguide |
High-res dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
167.0mm (6.6") |
191.0mm (7.5") |
| Width |
453.0mm (17.8") |
510.0mm (20.1") |
| Depth |
228.0mm (9") |
270.0mm (10.6") |
| Weight |
7.01kg (15.4lbs) |
8.64kg (19lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Finish |
n/a |
MDF, Wood-grain vinyl |
| Available Colors |
Walnut |
Black, Walnut, White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
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 | Polk ES30 digs deeper - 55Hz against 66Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (88dB vs 89dB) - both want much the same power. |
| Headroom | evenly matched | Similar power handling (120W vs 125W). |
| Size | depends | Monitor Audio Bronze C150 is easier to place; Polk ES30 is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Sealed vs Ported. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Price | B | Polk ES30 is cheaper - $299 against $395, about 24% less. |
A Monitor Audio Bronze C150 B Polk ES30
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?
Polk ES30 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 66Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Polk ES30 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Monitor Audio Bronze C150 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.