In this review, we will be comparing The Sevens 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 The Sevens and Klipsch R-51PM first before getting into our more
detailed comparison.
| Key Specs | Klipsch The Sevens | Klipsch R-51PM |
|---|
| Brand | Klipsch
United States · founded 1946 | Klipsch
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Built-in amplifier | 200-watt RMS (400-watt peak) | 120-watt RMS (240-watt peak) |
|---|
| Tweeter | 1" Tractrix Horn | 1.0" Tractrix Horn |
|---|
| Woofer | 6.5" Fiber-composite | 5.25" Copper-spun IMG |
|---|
| Frequency response | 39-25k Hz | 68-21k Hz |
|---|
| Max depth / sample rate | 24-bit / 192 kHz | 24-bit / 96 kHz |
|---|
| Bluetooth | Built-in 5.0 | Built-in 3.0 |
|---|
| App control | Yes | — |
|---|
| Weight | 9.03kg / 19.9lbs | 4.80kg / 10.6lbs |
|---|
| Dimensions (H x W x D) | 16.375" x 8.125" x 13.1875"
416.0 x 207.0 x 335.0mm | 13" x 7.0625" x 10.25"
330.2 x 179.4 x 260.3mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both The Sevens and R-51PM are 2-way speakers.
Klipsch The SevensKlipsch 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 The Sevens |
Klipsch R-51PM |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1.0-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.25-inch
|
The Sevens features a 1" Titanium Tractrix Horn Tweeter and 1 x 6.5" Fiber-composite Woofer. 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
The Sevens has a frequency range of 39-25k Hz whereas R-51PM has a frequency range of 68-21k Hz. With a minimum frequency of 39Hz, The Sevens can go significantly deeper on the low side and provide stronger bass compared to the R-51PM's min frequency of 68Hz.
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 The Sevens 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 The Sevens's and Klipsch R-51PM's external dimensions. Klipsch The Sevens has external dimensions of 416.0 x 207.0 x 335.0mm (16.375inch x 8.125inch x 13.1875inch) whereas Klipsch R-51PM has external dimensions of 330.2 x 179.4 x 260.3mm (13 x 7.0625 x 10.25inch).
Klipsch The Sevens is clearly the larger of the two speakers. Its body is 27.6mm wider, 85.8mm taller and 74.7mm deeper than Klipsch R-51PM.
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.
Klipsch The Sevens needs about 48% more floor or shelf area. Klipsch The Sevens is 75mm deeper, so it stands that much further out from the wall. Klipsch The Sevens is 86mm 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 Klipsch The Sevens is approximately 693.5cm2 / 107.5inch2 and base area of the Klipsch R-51PM is approximately 467.0cm2 / 72.4inch2. The Sevens requires 49% more surface area than the R-51PM 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 Klipsch The Sevens weighs 9.03kg / 19.9lbs and the Klipsch R-51PM weighs 4.80kg / 10.6lbs. This makes The Sevens 88% heavier than the R-51PM.
Here is a comparison of how The Sevens 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 The Sevens?
Here are the items that are included inside the box of The Sevens:
- Powered speaker (Primary)
- Passive speaker (Secondary)
- 2 Grilles (pre-installed)
- 6.5-feet AC power cord
- 13-feet Proprietary speaker cable
- 6.5-feet Proprietary extension cable
- 58-inch HDMI cable
- 5-feet USB-B to USB-A cable
- Remote control
- 2 AAA batteries
- Instruction Booklet
- Need Help? Card
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
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
39 Hz
vs
68 Hz
|
Generates deeper bass |
 High Frequency Response |
25k Hz
vs
21k Hz
|
Generates higher frequency |
 App-Based Control |
Apple iOS, Android
vs
None
|
Control the speaker via an app |
 USB Port |
USB-B
vs
No
|
USB port adds flexibility |
 HDMI Input |
ARC
vs
No
|
Connect HDMI sources directly |
 Height |
330mm
vs
416mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
467cm2
vs
693cm2
|
Takes less floor space |
 Price per pair* |
599USD
vs
1299USD
|
costs less (*prices may change depending on the seller, location and time) |
|
USB Port |
USB-B
vs
No
|
USB port adds flexibility |
 RCA Connection |
Yes
vs
No
|
Connection via RCA input |
| General |
Klipsch The Sevens |
Klipsch Reference R-51PM |
| Brand |
Klipsch |
Klipsch |
| Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
| Frequency Response |
39-25k Hz |
68-21k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
200-watt RMS |
120-watt RMS |
| Watts Peak (Max) |
400-watt RMS |
240-watt RMS |
| Max Bit Depth |
24-bit |
24-bit |
| Max Sample Rate |
192 kHz |
96 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
5.25" |
| Woofer Composition |
Fiber-composite |
Copper-spun IMG |
| Tweeter Size |
1" |
1.0" |
| Tweeter Type |
Tractrix Horn |
Tractrix Horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
1663Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
416.0mm (16.4") |
330.2mm (13") |
| Width |
207.0mm (8.1") |
179.4mm (7.1") |
| Depth |
335.0mm (13.2") |
260.3mm (10.2") |
| Weight |
9.03kg (19.9lbs) |
4.80kg (10.6lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF with genuine wood veneer |
n/a |
| Available Colors |
Black,Walnut |
n/a |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm |
3.5mm, RCA |
| USB Port |
USB-B |
USB-B |
| Phone Input |
Yes |
Yes |
| Subwoofer Output |
mono-RCA |
Wired |
| Digital Input |
Optical, HDMI |
Optical |
| HDMI Input |
ARC |
No |
| Headphone Jack |
No |
No |
| Ethernet Port |
No |
No |
Other |
|
|
| Parts Warranty |
1 Year |
1 Year |
| Labor Warranty |
1 Year |
1 Year |
These sit in different price classes - Klipsch The Sevens costs roughly 2.2x what Klipsch R-51PM does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | A | Klipsch The Sevens digs deeper - 39Hz against 68Hz. |
| Built-in power | A | Klipsch The Sevens has the bigger amplifier (200W vs 120W RMS). |
| Connections | A | Klipsch The Sevens adds HDMI. |
| Size | depends | Klipsch R-51PM is easier to place; Klipsch The Sevens is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Klipsch The Sevens: a sub output; Klipsch R-51PM: a sub output. |
| Price | B | Klipsch R-51PM is cheaper - $599 against $1,299, about 54% less; arguably a different class. |
A Klipsch The Sevens 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 The Sevens measures better, Klipsch R-51PM costs about about 117% 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 68Hz anyway, which makes the cheaper Klipsch R-51PM much easier to justify. In a large or open-plan room, Klipsch The Sevens has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Klipsch R-51PM 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.