In this review, we will be comparing AE309 and RTi A5, two Passive Floor-standing speakers from Acoustic Energy and Polk Audio.
Let's have a brief look at the main features
of AE309 and Polk RTi A5 first before getting into our more
detailed comparison.
| Key Specs | AE309 | Polk RTi A5 |
|---|
| Brand | Acoustic Energy
United Kingdom · founded 1987 | Polk Audio
United States · founded 1972 |
|---|
| Design | 3-way | 2-way |
|---|
| Tweeter | 1.1" dome with waveguide | 1" |
|---|
| Midrange | 5.2" | — |
|---|
| Woofer | 5.2" ceramic aluminium sandwich | 2 x 6.5" Polymer composite |
|---|
| Frequency response | 38Hz - 30kHz | 40-26k Hz |
|---|
| Sensitivity | 89 dB | 90 dB |
|---|
| Impedance | 6 ohms | 8 ohms |
|---|
| Power range | up to 175 watts | 20-250 watts |
|---|
| Weight | 22.00kg / 48.4lbs | 18.18kg / 40lbs |
|---|
| Dimensions (H x W x D) | 35.4" x 6.9" x 10.2"
900.0 x 175.0 x 260.0mm | 39-5/8" x 10-9/16" x 15-7/8"
1007.0 x 269.0 x 404.0mm |
|---|
What size room are the AE309 and Polk RTi A5 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* |
AE309 |
Polk RTi A5 |
| Near-field |
Bad |
Bad |
| Small Room |
Poor |
Poor |
| Mid-size Room |
Good |
Average |
| Large Room |
Good |
Good |
| Very Large Room |
Poor |
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.
Drivers
One of the fundamental differences between these two speakers is that AE309 is a 3-way design whereas the RTi A5 is a 2-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.
AE309Polk RTi A5
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
AE309 |
Polk RTi A5 |
|
Driver Setup
|
3-way
|
2-way
|
|
Tweeter
|
1.1-inch
|
1-inch
|
|
Midrange
|
1 x 5.2-inch |
- |
|
Woofer
|
1 x 5.2-inch
|
2 x 6.5-inch
|
AE309 features a 1.1" aluminium dome with waveguide Tweeter, a 5.2" Midrange and 1 x 5.2" ceramic aluminium sandwich Woofer with a Crossover frequency at 296Hz and 2560Hz. On the other hand, the RTi A5 features a 1" Tweeter and 2 x 6.5" Polymer composite Woofer.
Frequency Response
AE309 has a frequency range of 38Hz - 30kHz whereas RTi A5 has a frequency range of 40-26k Hz. With a minimum frequency of 38Hz, the AE309 can go slightly deeper then the RTi A5's min frequency of 40Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing 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
AE309 is a 6 ohms speaker compared to the RTi A5 which has a nominal impedance of 8 ohms.
These two speakers also have different sensitivity levels. AE309 sensitivity is rated at 89 dB and the RTi A5's is rated at 90 dB. This 1 dB difference makes the Polk RTi A5 a more sensitive speaker compared to AE309, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing 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.
RTi A5 can handle a max power of 250 watts RMS, whereas AE309 has a max power handling value of 175 watts RMS, 75 watts less than the RTi A5.
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
AE309 has a rear firing port whereas RTi A5 has a front firing ports. Polk RTi A5's front-firing port gives more flexibility in placement in regards to proximity to walls compared to AE309 with its rear-firing 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 AE309's and Polk RTi A5's external dimensions. AE309 has external dimensions of 900.0 x 175.0 x 260.0mm (35.4 x 6.9 x 10.2inch) whereas Polk RTi A5 has external dimensions of 1007.0 x 269.0 x 404.0mm (39-5/8 x 10-9/16 x 15-7/8inch).
Polk RTi A5 is clearly the larger of the two speakers. Its body is 94mm wider, 107mm taller and 144mm deeper than AE309.
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 RTi A5 needs about 139% more floor or shelf area. Polk RTi A5 is 144mm deeper, so it stands that much further out from the wall. Polk RTi A5 is 107mm 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 AE309 is approximately 455.0cm2 / 70.5inch2 and base area of the Polk RTi A5 is approximately 1086.8cm2 / 168.5inch2. The AE309 requires 58% less surface area than the RTi A5 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 AE309 weighs 22.00kg / 48.4lbs and the Polk RTi A5 weighs 18.18kg / 40lbs. This makes the AE309 21% heavier than the RTi A5.
Here is a comparison of how AE309 and RTi A5's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
What's in the Box of Polk RTi A5?
Here are the items that come with the RTi A5:
- Cherry floor-standing speaker
- Detachable black cloth grille
- 4 Screw-on spike feet
- Owners Manual
- Online registration sheet
- Polk Audio product brochure
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Low Frequency Response |
38 Hz
vs
40 Hz
|
Generates deeper bass |
 High Frequency Response |
30k Hz
vs
26k Hz
|
Generates higher frequency |
 Height |
900mm
vs
1007mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
455cm2
vs
1086cm2
|
Takes less floor space |
 Max Input Power |
250 watts
vs
175 watts
|
Handle more power from your amplifier |
 Sensitivity |
90 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
|
Woofer Size |
6.5 inches
vs
5.2 inches
|
Larger woofer |
|
Number of Woofers |
2
vs
1
|
More woofers |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Price per pair* |
798USD
vs
1899USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Acoustic Energy AE309 |
Polk Audio RTi A5 |
| Brand |
Acoustic Energy |
Polk Audio |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
up to 175 watts |
20-250 watts |
| Sensitivity |
89 dB |
90 dB |
| Impedance |
6 ohms |
8 ohms |
| Frequency Response |
38Hz - 30kHz |
40-26k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
5.2" |
6.5" |
| Woofer Composition |
ceramic aluminium sandwich |
Polymer composite |
| Woofer Surround Material |
n/a |
Butyl Rubber |
| Tweeter Size |
1.1" |
1" |
| Tweeter Type |
dome with waveguide |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5.2" |
No |
| Crossover Frequency |
296Hz and 2560Hz |
n/a |
| Firing Direction |
rear |
front |
Physical Specs |
|
|
| Height |
900.0mm (35.4") |
1007.0mm (39.6") |
| Width |
175.0mm (6.9") |
269.0mm (10.6") |
| Depth |
260.0mm (10.2") |
404.0mm (15.9") |
| Weight |
22.00kg (48.4lbs) |
18.18kg (40lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
high density MDF |
Real wood veneer |
| Available Colors |
Piano Gloss White, Piano Gloss Black, Real Walnut wood veneer |
Cherry |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
Yes |
Other |
|
|
| Parts Warranty |
|
5 Years |
| Labor Warranty |
|
5 Years |
These sit in different price classes - AE309 costs roughly 2.4x what Polk RTi A5 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 (38Hz vs 40Hz). |
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 90dB) - both want much the same power. |
| Amplifier match | B | Polk RTi A5 is the easier load at 8 ohms. |
| Headroom | B | Polk RTi A5 takes more power (250W vs 175W) - more in hand in a big room. |
| Size | depends | AE309 is easier to place; Polk RTi A5 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | B | Polk RTi A5: bi-amping. |
| Price | B | Polk RTi A5 is cheaper - $798 against $1,899, about 58% less; arguably a different class. |
A AE309 B Polk RTi A5
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 RTi A5 is the easier recommendation: it leads on most of the measured areas and costs less. Take AE309 if its size, looks or fit in your room suit you better. Match it to your room: we rate AE309 the better fit for a mid-size room, and Polk RTi A5 for a very large room. In a large or open-plan room, Polk RTi A5 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, AE309 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.