In this review, we will be comparing CSi A6 and R400, two Passive Center Channel speakers by Polk Audio Let's have a brief look at the main features
of Polk CSi A6 and Polk R400 first before getting into our more
detailed comparison.
What size room are the Polk CSi A6 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:
In the following sections, we will get into more detail in order to better understand how the Polk CSi A6 and Polk R400 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
Both CSi A6 and R400 are 2-way speakers.
| Driver |
Polk CSi A6 |
Polk R400 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
CSi A6 features a 1" silk/polymer Dynamic Balance Tweeter and 2 x 6.5" Dynamic Balance polymer composite 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
CSi A6 has a frequency range of 55-26k 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 CSi A6's min frequency of 55Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Center Channel class in our database.
Low Frequency
Center Channel Speakers
High Frequency
Center Channel Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
CSi A6 and R400 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. CSi A6 sensitivity is rated at 90 dB and the R400's is at 89 dB. This 1 dB difference makes the Polk CSi A6 a more sensitive speaker compared to Polk R400, 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. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
CSi A6 and R400 has the same power range of 20-200 watts.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
CSi A6 features Binding post type posts and R400 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk CSi A6's 5-Way post terminals
Polk R400's Binding post terminals
Cabinet Type and Port Position
Both CSi A6 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
Size of a speaker can sometimes become 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 CSi A6's and Polk R400's external dimensions. Polk CSi A6 has external dimensions of 199.0 x 612.0 x 362.0mm ( 7-13/16 x 24-1/16 x 14-1/4inch) 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 CSi A6 is 6mm narrower and 10mm less deeper than Polk CSi A6 but they have the same height of 199.0mm.
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 CSi A6 is approximately 2215.4cm2 / 343.4inch2 and base area of the Polk R400 is approximately 2299.0cm2 / 356.3inch2. The CSi A6 requires 4% 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 CSi A6 weighs 13.18kg / 29lbs and the Polk R400 weighs 14.91kg / 32.8lbs. This makes the R400 13% heavier than the CSi A6.
Here is a comparison of how CSi A6 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 CSi A6?
Here are the items that are included inside the box of CSi A6:
One cherry center channel speakerOne 9.5-inch kickstandOne 5.5-inch kickstand (installed)4 Self-adhesive rubber feetOwners ManualOnline registration sheetPolk Audio product brochure
What's in the Box of Polk R400?
Here are the items that come with the R400:
Center-channel loudspeakerGrilleOwners ManualOnline Registration
 Sensitivity |
90 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Base Surface Area |
2215cm2 (612x362mm)
vs
2299cm2 (618x372mm)
|
Takes less floor space |
 Low Frequency Response |
48 Hz
vs
55 Hz
|
Generates deeper bass |
 High Frequency Response |
39k Hz
vs
26k Hz
|
Generates higher frequency |
| General |
Polk Audio CSi A6 |
Polk Audio Reserve R400 |
| Brand |
Polk Audio |
Polk Audio |
| Speaker Type |
Center channel speaker (Cherry) |
Center channel speaker |
| Power Range |
20-200 watts |
20-200 watts |
| Sensitivity |
90 dB |
89 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
n/a |
4.1 ohms |
| Frequency Response |
55-26k Hz |
48-39K Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Dynamic Balance polymer composite |
Polypropylene Turbine Cone |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dynamic Balance |
Pinnacle Ring Radiator |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
N/A" |
N/A" |
| Crossover Frequency |
n/a |
2500Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
199.0mm (7.8") |
199.0mm (7.8") |
| Width |
612.0mm (24.1") |
618.0mm (24.3") |
| Depth |
362.0mm (14.3") |
372.0mm (14.6") |
| Weight |
13.18kg (29lbs) |
14.91kg (32.8lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Black, Cherry |
Black, Walnut |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |