In this review, we will be comparing R-41PM and R-51PM, two Powered Bookshelf speakers by Klipsch. Being Powered speakers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them.
Let's have a brief look at the main features
of Klipsch R-41PM and Klipsch R-51PM first before getting into our more
detailed comparison.
| Key Specs | Klipsch R-41PM | Klipsch R-51PM |
|---|
| Brand | Klipsch
United States · founded 1946 | Klipsch
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Built-in amplifier | 70-watt RMS (140-watt peak) | 120-watt RMS (240-watt peak) |
|---|
| Tweeter | 1.0" Tractrix Horn | 1.0" Tractrix Horn |
|---|
| Woofer | 4.0" Copper-spun IMG | 5.25" Copper-spun IMG |
|---|
| Frequency response | 76-21k Hz | 68-21k Hz |
|---|
| Max depth / sample rate | 24-bit / 96 kHz | 24-bit / 96 kHz |
|---|
| Bluetooth | Built-in 3.0 | Built-in 3.0 |
|---|
| Weight | 3.70kg / 8.1lbs | 4.80kg / 10.6lbs |
|---|
| Dimensions (H x W x D) | 11.0625" x 5.8125" x 9.5"
281.0 x 147.6 x 241.3mm | 13" x 7.0625" x 10.25"
330.2 x 179.4 x 260.3mm |
|---|
R-41PM and R-51PM are members of Klipsch's Reference (R) Bookshelf series of speakers. Below you can find the loudspeakers from this series.
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both R-41PM and R-51PM are 2-way speakers.
Klipsch R-41PMKlipsch R-51PM
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Klipsch R-41PM |
Klipsch R-51PM |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0-inch
|
1.0-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4.0-inch
|
1 x 5.25-inch
|
R-41PM features a 1.0" Aluminum LTS Tractrix Horn Tweeter and 1 x 4.0" Copper-spun IMG Woofer with a Crossover frequency at 1770Hz. On the other hand, the R-51PM features a 1.0" Aluminum LTS Tractrix Horn Tweeter and 1 x 5.25" Copper-spun IMG Woofer with a Crossover frequency at 1663Hz.
Frequency Response
R-41PM has a frequency range of 76-21k Hz whereas R-51PM has a frequency range of 68-21k Hz. With a minimum frequency of 68Hz, the R-51PM can go significantly deeper on the low side and provide stronger bass compared to the R-41PM's min frequency of 76Hz.
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.
Cabinet Type and Port Position
Both R-41PM and R-51PM 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.
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 Klipsch R-41PM's and Klipsch R-51PM's external dimensions. Klipsch R-41PM has external dimensions of 281.0 x 147.6 x 241.3mm (11.0625 x 5.8125 x 9.5inch) whereas Klipsch R-51PM has external dimensions of 330.2 x 179.4 x 260.3mm (13 x 7.0625 x 10.25inch).
Klipsch R-51PM is clearly the larger of the two speakers. Its body is 31.8mm wider, 49.2mm taller and 19mm deeper than Klipsch R-41PM.
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 Klipsch R-41PM is approximately 356.2cm2 / 55.2inch2 and base area of the Klipsch R-51PM is approximately 467.0cm2 / 72.4inch2. The R-41PM requires 24% less surface area than the R-51PM 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 Klipsch R-41PM weighs 3.70kg / 8.1lbs and the Klipsch R-51PM weighs 4.80kg / 10.6lbs. This makes the R-51PM 30% heavier than the R-41PM.
Here is a comparison of how R-41PM and R-51PM's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Klipsch R-41PM?
Here are the items that are included inside the box of R-41PM:
- Powered speaker (right)
- Passive speaker (left)
- 2 Grilles
- 68-inch AC power cord
- Remote control
- 2
What's in the Box of Klipsch R-51PM?
Here are the items that come with the R-51PM:
- Powered speaker (right)
- Passive speaker (left)
- 2 Grilles
- 68-inch AC power cord
- Remote control
- 2
 Height |
281mm
vs
330mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
356cm2
vs
467cm2
|
Takes less floor space |
 Price per pair* |
499USD
vs
599USD
|
costs less (*prices may change depending on the seller, location and time) |
 USB Port |
USB-B
vs
No
|
USB port adds flexibility |
 Woofer Size |
5.25 inches
vs
4.0 inches
|
Larger woofer |
|
Low Frequency Response |
68 Hz
vs
76 Hz
|
Generates deeper bass |
|
USB Port |
USB-B
vs
No
|
USB port adds flexibility |
| General |
Klipsch Reference R-41PM |
Klipsch Reference R-51PM |
| Brand |
Klipsch |
Klipsch |
| Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
| Frequency Response |
76-21k Hz |
68-21k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
70-watt RMS |
120-watt RMS |
| Watts Peak (Max) |
140-watt RMS |
240-watt RMS |
| Max Bit Depth |
24-bit |
24-bit |
| Max Sample Rate |
96 kHz |
96 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
4.0" |
5.25" |
| Woofer Composition |
Copper-spun IMG |
Copper-spun IMG |
| Tweeter Size |
1.0" |
1.0" |
| Tweeter Type |
Tractrix Horn |
Tractrix Horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1770Hz |
1663Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
281.0mm (11.1") |
330.2mm (13") |
| Width |
147.6mm (5.8") |
179.4mm (7.1") |
| Depth |
241.3mm (9.5") |
260.3mm (10.2") |
| Weight |
3.70kg (8.1lbs) |
4.80kg (10.6lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm, RCA |
3.5mm, RCA |
| USB Port |
USB-B |
USB-B |
| Phone Input |
Yes |
Yes |
| Subwoofer Output |
Wired |
Wired |
| Digital Input |
Optical |
Optical |
| HDMI Input |
No |
No |
| Headphone Jack |
No |
No |
| Ethernet Port |
No |
No |
Other |
|
|
| Parts Warranty |
1 Year |
1 Year |
| Labor Warranty |
1 Year |
1 Year |
Siblings in Klipsch's Reference (R) Bookshelf series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | B | Klipsch R-51PM digs deeper - 68Hz against 76Hz. A subwoofer would even that out. |
| Built-in power | B | Klipsch R-51PM has the bigger amplifier (120W vs 70W RMS). |
| Connections | evenly matched | The same set of inputs and streaming options. |
| Size | depends | Klipsch R-41PM is easier to place; Klipsch R-51PM is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Klipsch R-41PM: a sub output; Klipsch R-51PM: a sub output. |
| Price | A | Klipsch R-41PM is cheaper - $499 against $599, about 17% less. |
A Klipsch R-41PM B Klipsch R-51PM
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?
The usual trade-off: Klipsch R-51PM measures better, Klipsch R-41PM costs about about 20% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 76Hz anyway, which makes the cheaper Klipsch R-41PM much easier to justify. In a large or open-plan room, Klipsch R-51PM has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Klipsch R-41PM 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.