In this review, we will be comparing RTi A1 and RP-400M, two Passive Bookshelf speakers from Polk Audio and Klipsch.
Let's have a brief look at the main features
of Polk RTi A1 and Klipsch RP-400M first before getting into our more
detailed comparison.
| Key Specs | Polk RTi A1 | Klipsch RP-400M |
|---|
| Brand | Polk Audio
United States · founded 1972 | Klipsch
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Dome | 1" Tractrix Horn |
|---|
| Woofer | 5.25" Polymer composite | 4" Cerametallic |
|---|
| Frequency response | 60-26k Hz | 52-25k Hz |
|---|
| Sensitivity | 89 dB | 93 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 20-125 watts | up to 50 watts |
|---|
| Weight | 5.44kg / 12lbs | 4.10kg / 9lbs |
|---|
| Dimensions (H x W x D) | 12.0" x 7.3" x 11.5"
304.8 x 187.5 x 292.1mm | 11.7" x 5.6" x 7.5"
298.0 x 144.0 x 191.0mm |
|---|
What size room are the Polk RTi A1 and Klipsch RP-400M 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 RTi A1 |
Klipsch RP-400M |
| Near-field |
Poor |
Good |
| Small Room |
Average |
Good |
| Mid-size Room |
Good |
Average |
| Large Room |
Average |
Poor |
| Very Large Room |
Poor |
No way |
(* 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 RTi A1 and RP-400M are 2-way speakers.
Polk RTi A1Klipsch RP-400M
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 RTi A1 |
Klipsch RP-400M |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 4-inch
|
RTi A1 features a 1" silk polymer composite Dome Tweeter and 1 x 5.25" Polymer composite Woofer with a Crossover frequency at 1900Hz. On the other hand, the RP-400M features a 1" Tractrix Horn Tweeter and 1 x 4" Cerametallic Woofer with a Crossover frequency at 1500Hz.
Frequency Response
RTi A1 has a frequency range of 60-26k Hz whereas RP-400M has a frequency range of 52-25k Hz. With a minimum frequency of 52Hz, the RP-400M can go significantly deeper on the low side and provide stronger bass compared to the RTi A1's min frequency of 60Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf 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
RTi A1 and RP-400M have the same Impedance of 8 ohms but where they differ is the sensitivity levels. RTi A1 sensitivity is rated at 89 dB and the RP-400M's is at 93 dB. This 4 dB difference makes the Klipsch RP-400M a more sensitive speaker compared to Polk RTi A1, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf 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 A1 can handle a max power of 125 watts RMS, whereas RP-400M has a max power handling value of 50 watts RMS, 75 watts less than the RTi A1.
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
RTi A1 features Pair of Dual 5-way Binding Posts - Gold-Plated posts which make bi-amping or bi-wiring possible. RP-400M has a Single binding posts which doesn't feature bi-amping/bi-wiring.
Klipsch RP-400M's Single binding posts terminals
Cabinet Type and Port Position
RTi A1 has a back and front firing port whereas RP-400M has a rear firing ports.
Klipsch RP-400M Tractrix horn-shaped 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 RTi A1's and Klipsch RP-400M's external dimensions. Polk RTi A1 has external dimensions of 304.8 x 187.5 x 292.1mm (12.0 x 7.3 x 11.5inch) whereas Klipsch RP-400M has external dimensions of 298.0 x 144.0 x 191.0mm (11.7 x 5.6 x 7.5inch).
Polk RTi A1 is clearly the larger of the two speakers. Its body is 43.5mm wider, 6.8mm taller and 101.1mm deeper than Klipsch RP-400M.
Below you can see the front view size comparison of Polk RTi A1 and Klipsch RP-400M in scale.
Comparison image of Polk RTi A1 and Klipsch RP-400M Size and External Dimensions
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 RTi A1 is approximately 547.7cm2 / 84.9inch2 and base area of the Klipsch RP-400M is approximately 275.0cm2 / 42.6inch2. The RTi A1 requires 99% more surface area than the RP-400M which gives it a small disadvantage on placement in tight spaces.
Here is another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
Size Comparison image of Polk RTi A1 and Klipsch RP-400M on a Media Console
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 RTi A1 weighs 5.44kg / 12lbs and the Klipsch RP-400M weighs 4.10kg / 9lbs. This makes the RTi A1 33% heavier than the RP-400M.
Here is a comparison of how RTi A1 and RP-400M's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Polk RTi A1?
Here are the items that are included inside the box of RTi A1:
- 2 Cherry bookshelf speakers
- 2 Self-tapping screws
- 8 Self-adhesive rubber feet
- Owner's Manual
- Template
- Online registration sheet
- Polk Audio product brochure
What's in the Box of Klipsch RP-400M?
Here are the items that come with the RP-400M:
- 2 Bookshelf loudspeakers
- 2 Grilles (installed)
- 8 Self-adhesive rubber feet
- User Manual
- Important Safety Instructions
- Warranty Information
 Max Input Power |
125 watts
vs
50 watts
|
Handle more power from your amplifier |
 Woofer Size |
5.25 inches
vs
4 inches
|
Larger woofer |
 High Frequency Response |
26k Hz
vs
25k Hz
|
Generates higher frequency |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Price per pair* |
382USD
vs
399USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
93 dB
vs
89 dB
|
Play louder with same amount of amplification power |
|
Low Frequency Response |
52 Hz
vs
60 Hz
|
Generates deeper bass |
 Height |
298mm
vs
304mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
275cm2
vs
547cm2
|
Takes less floor space |
| General |
Polk Audio RTi A1 |
Klipsch Reference Premiere RP-400M |
| Brand |
Polk Audio |
Klipsch |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
20-125 watts |
up to 50 watts |
| Sensitivity |
89 dB |
93 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
60-26k Hz |
52-25k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
4" |
| Woofer Composition |
Polymer composite |
Cerametallic |
| Woofer Surround Material |
Butyl rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Dome |
Tractrix Horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1900Hz |
1500Hz |
| Firing Direction |
back and front |
rear |
Physical Specs |
|
|
| Height |
304.8mm (12") |
298.0mm (11.7") |
| Width |
187.5mm (7.4") |
144.0mm (5.7") |
| Depth |
292.1mm (11.5") |
191.0mm (7.5") |
| Weight |
5.44kg (12lbs) |
4.10kg (9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
Real wood veneer |
MDF/Wood-grain vinyl |
| Available Colors |
Black, Cherry |
Ebony, Walnut, Piano Black |
| Mounting Bracket |
Keyhole |
Keyhole |
| Recommended Stand Height |
28-36" |
28-30" |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
A generation apart: Klipsch RP-400M is the newer design, against a 2008 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 | Klipsch RP-400M digs deeper - 52Hz against 60Hz. A subwoofer would even that out. |
| Amplifier needs | B | Klipsch RP-400M is more sensitive (93dB vs 89dB), so it goes louder on the same amplifier. |
| Headroom | A | Polk RTi A1 takes more power (125W vs 50W) - more in hand in a big room. |
| Size | depends | Klipsch RP-400M is easier to place; Polk RTi A1 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Polk RTi A1: bi-amping. Klipsch RP-400M sits in a wider range (17 models), so a matched surround system is easier later. |
| Price | evenly matched | Much the same money ($382 vs $399 a pair). |
A Polk RTi A1 B Klipsch RP-400M
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?
Klipsch RP-400M 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 60Hz anyway, so judge these on the other rows instead. Match it to your room: we rate Polk RTi A1 the better fit for a mid-size room and a large room, and Klipsch RP-400M for near-field listening and a small room.
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.