In this review, we will be comparing Monitor SE Atom and R-51M, two Passive Bookshelf speakers from Paradigm and Klipsch.
Let's have a brief look at the main features
of Paradigm SE Atom and Klipsch R-51M first before getting into our more
detailed comparison.
| Key Specs | Paradigm SE Atom | Klipsch R-51M |
|---|
| Brand | Paradigm
Canada · founded 1982 | Klipsch
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Hard-Dome | 1" Tractrix Horn |
|---|
| Woofer | 5.5" Mineral-filled polypropylene | 5.25" Copper-spun IMG |
|---|
| Frequency response | 61-21k Hz | 62-21k Hz |
|---|
| Sensitivity | 89 dB | 93 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 15-100 watts | Up to 85 watts |
|---|
| Weight | 5.45kg / 12lbs | 5.00kg / 11lbs |
|---|
| Dimensions (H x W x D) | 12-3/4" x 7-1/8" x 10-7/8"
324.0 x 181.0 x 277.0mm | 13.3" x 7.0" x 8.4"
338.0 x 178.0 x 215.0mm |
|---|
What size room are the Paradigm SE Atom and Klipsch R-51M 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* |
Paradigm SE Atom |
Klipsch R-51M |
| Near-field |
Average |
Average |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
Bad |
Bad |
(* 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 Monitor SE Atom and R-51M are 2-way speakers.
Paradigm SE AtomKlipsch R-51M
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Paradigm SE Atom |
Klipsch R-51M |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.5-inch
|
1 x 5.25-inch
|
Monitor SE Atom features a 1" Hard-Dome Tweeter and 1 x 5.5" Mineral-filled polypropylene Woofer. On the other hand, the R-51M features a 1" Tractrix Horn Tweeter and 1 x 5.25" Copper-spun IMG Woofer with a Crossover frequency at 1660Hz.
Frequency Response
Monitor SE Atom has a frequency range of 61-21k Hz whereas R-51M has a frequency range of 62-21k Hz. With a minimum frequency of 61Hz, the Monitor SE Atom can go slightly deeper then the R-51M's min frequency of 62Hz.
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
Monitor SE Atom and R-51M have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Monitor SE Atom sensitivity is rated at 89 dB and the R-51M's is at 93 dB. This 4 dB difference makes the Klipsch R-51M a more sensitive speaker compared to Paradigm SE Atom, 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.
Monitor SE Atom can handle a max power of 100 watts RMS, whereas R-51M has a max power handling value of 85 watts RMS, 15 watts less than the Monitor SE Atom.
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
Monitor SE Atom features Single Gold Plated Binding Posts - 5-way type posts and R-51M has a Single Gold Plated Binding Posts - 5-way type posts. None of these speakers feature bi-amping/bi-wiring.
Paradigm SE Atom's Post terminals
Klipsch R-51M's Single Gold Plated Binding Posts - 5-way terminals
Cabinet Type and Port Position
Both Monitor SE Atom and R-51M 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 Paradigm SE Atom's and Klipsch R-51M's external dimensions. Paradigm SE Atom has external dimensions of 324.0 x 181.0 x 277.0mm (12-3/4 x 7-1/8 x 10-7/8inch) whereas Klipsch R-51M has external dimensions of 338.0 x 178.0 x 215.0mm (13.3 x 7.0 x 8.4inch).
Klipsch R-51M is 3mm narrower and 62mm less deeper than Paradigm SE Atom but it is also 14mm taller.
Below you can see the front view size comparison of Paradigm SE Atom and Klipsch R-51M in scale.
Comparison image of Paradigm SE Atom and Klipsch R-51M 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 Paradigm SE Atom is approximately 501.4cm2 / 77.7inch2 and base area of the Klipsch R-51M is approximately 382.7cm2 / 59.3inch2. The Monitor SE Atom requires 31% more surface area than the R-51M 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 Paradigm SE Atom and Klipsch R-51M 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 Paradigm SE Atom weighs 5.45kg / 12lbs and the Klipsch R-51M weighs 5.00kg / 11lbs. This makes the Monitor SE Atom 9% heavier than the R-51M.
Here is a comparison of how Monitor SE Atom and R-51M's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Paradigm SE Atom?
Here are the items that are included inside the box of Monitor SE Atom:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 8 Rubber feet
- Owner's Manual
- Online Registration Card
What's in the Box of Klipsch R-51M?
Here are the items that come with the R-51M:
- 2 Bookshelf loudspeakers
- 2 Grilles (installed)
- 8 Self-adhesive rubber feet
- Quick Setup Guide
- Important Safety Instructions
- Warranty Information
 Max Input Power |
100 watts
vs
85 watts
|
Handle more power from your amplifier |
 Woofer Size |
5.5 inches
vs
5.25 inches
|
Larger woofer |
|
Low Frequency Response |
61 Hz
vs
62 Hz
|
Generates deeper bass |
 Height |
324mm
vs
338mm
|
Easier to fit in smaller spaces |
 Price per pair* |
300USD
vs
359USD
|
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 |
 Base Surface Area |
382cm2
vs
501cm2
|
Takes less floor space |
| General |
Paradigm Monitor SE Atom |
Klipsch Reference R-51M |
| Brand |
Paradigm |
Klipsch |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
15-100 watts |
Up to 85 watts |
| Sensitivity |
89 dB |
93 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
61-21k Hz |
62-21k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.5" |
5.25" |
| Woofer Composition |
Mineral-filled polypropylene |
Copper-spun IMG |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Hard-Dome |
Tractrix Horn |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
1660Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
324.0mm (12.8") |
338.0mm (13.3") |
| Width |
181.0mm (7.1") |
178.0mm (7") |
| Depth |
277.0mm (10.9") |
215.0mm (8.5") |
| Weight |
5.45kg (12lbs) |
5.00kg (11lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Vinyl |
MDF/Wood-grain vinyl |
| Available Colors |
Matte Black,Gloss White |
Black |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
26-28" |
24-28" |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (61Hz vs 62Hz). |
| Amplifier needs | B | Klipsch R-51M is more sensitive (93dB vs 89dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (100W vs 85W). |
| Size | depends | Klipsch R-51M is easier to place; Paradigm SE Atom is bigger, which usually goes with fuller bass. Your room decides. |
| Price | A | Paradigm SE Atom is cheaper - $300 against $359, about 16% less. |
A Paradigm SE Atom B Klipsch R-51M
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-51M measures better, Paradigm SE Atom 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 your amplifier is modest, vintage or valve-based, Klipsch R-51M 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.