In this review, we will be comparing Reserve R350 and R400, two Passive Center Channel speakers by Polk Audio.
Let's have a brief look at the main features
of Polk Audio Reserve R350 and Polk R400 first before getting into our more
detailed comparison.
| Key Specs | Polk Audio Reserve R350 | Polk R400 |
|---|
| Brand | Polk Audio
United States · founded 1972 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Ring Radiator | 1" Pinnacle Ring Radiator |
|---|
| Woofer | 4 x 4" | 2 x 6.5" Polypropylene Turbine Cone |
|---|
| Frequency response | 75-35k Hz | 48-39K Hz |
|---|
| Sensitivity | 87 dB | 89 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | — | 20-200 watts |
|---|
| Weight | 9.07kg / 20lbs | 14.91kg / 32.8lbs |
|---|
| Dimensions (H x W x D) | 5-9/16" x 30" x 7-1/4"
141.3 x 762.0 x 184.2mm | 7-13/16" x 24-5/16" x 14-5/8"
199.0 x 618.0 x 372.0mm |
|---|
Reserve R350 and R400 are members of Polk Audio's Reserve series of speakers. Below you can find the loudspeakers from this series.
Polk Audio Reserve Series
History
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Reserve R350 and R400 are 2-way speakers.
Polk Audio Reserve R350Polk 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 |
Polk Audio Reserve R350 |
Polk R400 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
4 x 4-inch
|
2 x 6.5-inch
|
Reserve R350 features a 1" Ring Radiator Tweeter and 4 x 4" Woofer. 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
Reserve R350 has a frequency range of 75-35k Hz whereas R400 has a frequency range of 48-39K Hz. With a minimum frequency of 48Hz, the R400 can go significantly deeper on the low side and provide stronger bass compared to the Reserve R350's min frequency of 75Hz.
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
Reserve R350 and R400 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Reserve R350 sensitivity is rated at 87 dB and the R400's is at 89 dB. This 2 dB difference makes the Polk R400 a more sensitive speaker compared to Polk Audio Reserve R350, hence will play louder with the same amount of watts.
Sensitivity
Center Channel Speakers
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
Reserve R350 features Binding post type posts and R400 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk R400's Binding post terminals
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 Polk Audio Reserve R350's and Polk R400's external dimensions. Polk Audio Reserve R350 has external dimensions of 141.3 x 762.0 x 184.2mm () 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 Audio Reserve R350 is 57.7mm shorter and 187.8mm less deeper than Polk R400 but it is also 144mm wider.
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 64% more floor or shelf area. Polk R400 is 188mm deeper, so it stands that much further out from the wall. Polk R400 is 58mm 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 Polk Audio Reserve R350 is approximately 1403.6cm2 / 217.6inch2 and base area of the Polk R400 is approximately 2299.0cm2 / 356.3inch2. The Reserve R350 requires 39% 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 Polk Audio Reserve R350 weighs 9.07kg / 20lbs and the Polk R400 weighs 14.91kg / 32.8lbs. This makes the R400 64% heavier than the Reserve R350.
Here is a comparison of how Reserve R350 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
 Number of Woofers |
4
vs
2
|
More woofers |
 Height |
141mm
vs
199mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1403cm2
vs
2299cm2
|
Takes less floor space |
 Sensitivity |
89 dB
vs
87 dB
|
Play louder with same amount of amplification power |
|
Woofer Size |
6.5 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
48 Hz
vs
75 Hz
|
Generates deeper bass |
 High Frequency Response |
39k Hz
vs
35k Hz
|
Generates higher frequency |
| General |
Polk Audio Reserve R350 |
Polk Audio Reserve R400 |
| Brand |
Polk Audio |
Polk Audio |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Sensitivity |
87 dB |
89 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
4.1 ohms |
| Frequency Response |
75-35k Hz |
48-39K Hz |
Drivers |
|
|
| Woofer Quantity |
4 |
2 |
| Woofer Size |
4" |
6.5" |
| Woofer Composition |
|
Polypropylene Turbine Cone |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Ring Radiator |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
n/a |
rear |
Physical Specs |
|
|
| Height |
141.3mm (5.6") |
199.0mm (7.8") |
| Width |
762.0mm (30") |
618.0mm (24.3") |
| Depth |
184.2mm (7.3") |
372.0mm (14.6") |
| Weight |
9.07kg (20lbs) |
14.91kg (32.8lbs) |
| Enclosure |
|
Bass Reflex |
| Available Colors |
Brown |
Black, Walnut |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
Siblings in Polk Audio's Reserve series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | B | Polk R400 digs deeper - 48Hz against 75Hz. |
| Amplifier needs | B | Polk R400 is more sensitive (89dB vs 87dB), so it goes louder on the same amplifier. |
| Size | depends | Polk Audio Reserve R350 is easier to place; Polk R400 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 | evenly matched | Much the same money ($649 vs $649 a pair). |
A Polk Audio Reserve R350 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?
Polk R400 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 75Hz anyway, so judge these on the other rows instead. 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, Polk Audio Reserve R350 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.