In this review, we will be comparing R400 and Ultra Center, two Passive Center Channel speakers from Polk Audio and SVS.
Let's have a brief look at the main features
of Polk R400 and SVS Ultra Center first before getting into our more
detailed comparison.
| Key Specs | Polk R400 | SVS Ultra Center |
|---|
| Brand | Polk Audio
United States · founded 1972 | SVS
United States · founded 1998 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 1" Pinnacle Ring Radiator | 1" Dome |
|---|
| Midrange | — | 4" |
|---|
| Woofer | 2 x 6.5" Polypropylene Turbine Cone | 2 x 6.5" composite glass-fiber |
|---|
| Frequency response | 48-39K Hz | 45-32k Hz |
|---|
| Sensitivity | 89 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-200 watts | 20-225 watts |
|---|
| Weight | 14.91kg / 32.8lbs | 14.09kg / 31lbs |
|---|
| Dimensions (H x W x D) | 7-13/16" x 24-5/16" x 14-5/8"
199.0 x 618.0 x 372.0mm | 8-1/8" x 22-1/16" x 11-3/16"
207.0 x 561.0 x 285.0mm |
|---|
What size room are the Polk R400 and SVS Ultra Center 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* |
Polk R400 |
SVS Ultra Center |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Poor |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
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 R400 is a 2-way design whereas the Ultra Center is a 3-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.
Polk R400SVS Ultra Center
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Polk R400 |
SVS Ultra Center |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 4-inch |
|
Woofer
|
2 x 6.5-inch
|
2 x 6.5-inch
|
R400 features a 1" Pinnacle Ring Radiator Tweeter and 2 x 6.5" Polypropylene Turbine Cone Woofer with a Crossover frequency at 2500Hz. On the other hand, the Ultra Center features a 1" aluminum Dome Tweeter, a 4" Midrange and 2 x 6.5" composite glass-fiber Woofer with a Crossover frequency at 500Hz and 2200Hz.
Frequency Response
R400 has a frequency range of 48-39K Hz whereas Ultra Center has a frequency range of 45-32k Hz. With a minimum frequency of 45Hz, the Ultra Center can go slightly deeper then 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
R400 and Ultra Center have the same Impedance of 8 ohms but where they differ is the sensitivity levels. R400 sensitivity is rated at 89 dB and the Ultra Center's is at 87 dB. This 2 dB difference makes the Polk R400 a more sensitive speaker compared to SVS Ultra Center, 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.
Ultra Center can handle a max power of 225 watts RMS, whereas R400 has a max power handling value of 200 watts RMS, 25 watts less than the Ultra Center.
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.
Input Type and Bi-Amping / Bi-Wiring
Ultra Center features 5-Way post posts which make bi-amping or bi-wiring possible. R400 has a Binding post which doesn't feature bi-amping/bi-wiring.
Polk R400's Binding post terminals
SVS Ultra Center's 5-Way post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both R400 and Ultra Center 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 Polk R400's and SVS Ultra Center's external dimensions. 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) whereas SVS Ultra Center has external dimensions of 207.0 x 561.0 x 285.0mm (8-1/8 x 22-1/16 x 11-3/16inch).
SVS Ultra Center is 57mm narrower and 87mm less deeper than Polk R400 but it is also 8mm taller.
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 44% more floor or shelf area. Polk R400 is 87mm deeper, so it stands that much further out from the wall.
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 R400 is approximately 2299.0cm2 / 356.3inch2 and base area of the SVS Ultra Center is approximately 1598.9cm2 / 247.8inch2. The R400 requires 44% more surface area than the Ultra Center which gives it a small disadvantage 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 R400 weighs 14.91kg / 32.8lbs and the SVS Ultra Center weighs 14.09kg / 31lbs. This makes the R400 6% heavier than the Ultra Center.
Here is a comparison of how R400 and Ultra Center'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 are included inside the box of R400:
- Center-channel loudspeaker
- Grille
- Owners Manual
- Online Registration
What's in the Box of SVS Ultra Center?
Here are the items that come with the Ultra Center:
- Center channel loudspeaker
- Grille
- 2 Terminal jumpers (pre-installed)
- 4 Rubber feet
- Owners Manual
- SVS brochure
- Online Product Registration Card
 Sensitivity |
89 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 High Frequency Response |
39k Hz
vs
32k Hz
|
Generates higher frequency |
 Height |
199mm
vs
207mm
|
Easier to fit in smaller spaces |
 Price per pair* |
649USD
vs
799USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
225 watts
vs
200 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Low Frequency Response |
45 Hz
vs
48 Hz
|
Generates deeper bass |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Base Surface Area |
1598cm2
vs
2299cm2
|
Takes less floor space |
| General |
Polk Audio Reserve R400 |
SVS Ultra Center |
| Brand |
Polk Audio |
SVS |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
20-200 watts |
20-225 watts |
| Sensitivity |
89 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Impedance |
4.1 ohms |
n/a |
| Frequency Response |
48-39K Hz |
45-32k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
6.5" |
6.5" |
| Woofer Composition |
Polypropylene Turbine Cone |
composite glass-fiber |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Pinnacle Ring Radiator |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
4" |
| Crossover Frequency |
2500Hz |
500Hz and 2200Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
199.0mm (7.8") |
207.0mm (8.1") |
| Width |
618.0mm (24.3") |
561.0mm (22.1") |
| Depth |
372.0mm (14.6") |
285.0mm (11.2") |
| Weight |
14.91kg (32.8lbs) |
14.09kg (31lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Black, Walnut |
Black Oak,Piano Gloss Black,Piano Gloss White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
A generation apart: Polk R400 is the newer design, against a 2013 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | B | SVS Ultra Center digs deeper - 45Hz against 48Hz. A subwoofer would even that out. |
| Amplifier needs | A | Polk R400 is more sensitive (89dB vs 87dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (200W vs 225W). |
| Size | depends | SVS Ultra Center is easier to place; Polk R400 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | SVS Ultra Center: bi-amping. Polk R400 sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | A | Polk R400 is cheaper - $649 against $799, about 19% less. |
A Polk R400 B SVS Ultra Center
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. Match it to your room: we rate Polk R400 the better fit for a small room, and SVS Ultra Center for a large room and a very large room. If your amplifier is modest, vintage or valve-based, Polk R400 is the safer partner - the other will want more current or more watts to sound its best.
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.