In this review, we will be comparing AE307 and R400, two Passive Center Channel speakers from Acoustic Energy and Polk Audio.
Let's have a brief look at the main features
of AE307 and Polk R400 first before getting into our more
detailed comparison.
| Key Specs | AE307 | Polk R400 |
|---|
| Brand | Acoustic Energy
United Kingdom · founded 1987 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1.1" dome with waveguide | 1" Pinnacle Ring Radiator |
|---|
| Woofer | 2 x 5.2" ceramic aluminium sandwich | 2 x 6.5" Polypropylene Turbine Cone |
|---|
| Frequency response | 42Hz - 30kHz | 48-39K Hz |
|---|
| Sensitivity | 89 dB | 89 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | up to 175 watts | 20-200 watts |
|---|
| Weight | 9.00kg / 19.8lbs | 14.91kg / 32.8lbs |
|---|
| Dimensions (H x W x D) | 6.9" x 18.1" x 10.2"
175.0 x 460.0 x 260.0mm | 7-13/16" x 24-5/16" x 14-5/8"
199.0 x 618.0 x 372.0mm |
|---|
What size room are the AE307 and Polk R400 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* |
AE307 |
Polk R400 |
| 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 AE307 and R400 are 2-way speakers.
AE307Polk R400
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
AE307 |
Polk R400 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 5.2-inch
|
2 x 6.5-inch
|
AE307 features a 1.1" aluminium dome with waveguide Tweeter and 2 x 5.2" ceramic aluminium sandwich Woofer with a Crossover frequency at 2560Hz. On the other hand, the R400 features a 1" Pinnacle Ring Radiator Tweeter and 2 x 6.5" Polypropylene Turbine Cone Woofer with a Crossover frequency at 2500Hz.
Frequency Response
AE307 has a frequency range of 42Hz - 30kHz whereas R400 has a frequency range of 48-39K Hz. With a minimum frequency of 42Hz, the AE307 can go significantly deeper on the low side and provide stronger bass compared to the R400'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 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
AE307 is a 6 ohms speaker compared to the R400 which has a nominal impedance of 8 ohms.
On the other hand, they have the same sensitivity of 89 dBdB.
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.
R400 can handle a max power of 200 watts RMS, whereas AE307 has a max power handling value of 175 watts RMS, 25 watts less than the R400.
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.
Cabinet Type and Port Position
Both AE307 and R400 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.
Polk R400 dual 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 AE307's and Polk R400's external dimensions. AE307 has external dimensions of 175.0 x 460.0 x 260.0mm (6.9 x 18.1 x 10.2inch) whereas Polk R400 has external dimensions of 199.0 x 618.0 x 372.0mm (7-13/16 x 24-5/16 x 14-5/8inch).
Polk R400 is clearly the larger of the two speakers. Its body is 158mm wider, 24mm taller and 112mm deeper than AE307.
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.
Polk R400 needs about 92% more floor or shelf area. Polk R400 is 112mm deeper, so it stands that much further out from the wall. Polk R400 is 24mm 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 AE307 is approximately 1196.0cm2 / 185.4inch2 and base area of the Polk R400 is approximately 2299.0cm2 / 356.3inch2. The AE307 requires 48% less surface area than the R400 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 AE307 weighs 9.00kg / 19.8lbs and the Polk R400 weighs 14.91kg / 32.8lbs. This makes the R400 66% heavier than the AE307.
Here is a comparison of how AE307 and R400's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
What's in the Box of Polk R400?
Here are the items that come with the R400:
- Center-channel loudspeaker
- Grille
- Owners Manual
- Online Registration
 Low Frequency Response |
42 Hz
vs
48 Hz
|
Generates deeper bass |
 Height |
175mm
vs
199mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1196cm2
vs
2299cm2
|
Takes less floor space |
 Max Input Power |
200 watts
vs
175 watts
|
Handle more power from your amplifier |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
|
Woofer Size |
6.5 inches
vs
5.2 inches
|
Larger woofer |
 High Frequency Response |
39k Hz
vs
30k Hz
|
Generates higher frequency |
 Price per pair* |
649USD
vs
799USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Acoustic Energy AE307 |
Polk Audio Reserve R400 |
| Brand |
Acoustic Energy |
Polk Audio |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
up to 175 watts |
20-200 watts |
| Sensitivity |
89 dB |
89 dB |
| Impedance |
6 ohms |
8 ohms |
| Impedance |
n/a |
4.1 ohms |
| Frequency Response |
42Hz - 30kHz |
48-39K Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5.2" |
6.5" |
| Woofer Composition |
ceramic aluminium sandwich |
Polypropylene Turbine Cone |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1.1" |
1" |
| Tweeter Type |
dome with waveguide |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2560Hz |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
175.0mm (6.9") |
199.0mm (7.8") |
| Width |
460.0mm (18.1") |
618.0mm (24.3") |
| Depth |
260.0mm (10.2") |
372.0mm (14.6") |
| Weight |
9.00kg (19.8lbs) |
14.91kg (32.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
high density MDF |
n/a |
| Available Colors |
Piano Gloss White, Piano Gloss Black, Real Walnut wood veneer |
Black, Walnut |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
|
5 Years |
| Labor Warranty |
|
5 Years |
A generation apart: Polk R400 is the newer design, against a 2017 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | A | AE307 digs deeper - 42Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 89dB) - both want much the same power. |
| Amplifier match | B | Polk R400 is the easier load at 8 ohms. |
| Headroom | evenly matched | Similar power handling (175W vs 200W). |
| Size | depends | AE307 is easier to place; Polk R400 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Polk R400 sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | B | Polk R400 is cheaper - $649 against $799, about 19% less. |
A AE307 B Polk R400
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 48Hz anyway, which makes the cheaper Polk R400 much easier to justify. In a large or open-plan room, Polk R400 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, AE307 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.