In this review, we will be comparing R-51M and S 803, two Passive Bookshelf speakers from Klipsch and Jamo.
Let's have a brief look at the main features
of Klipsch R-51M and Jamo S 803 first before getting into our more
detailed comparison.
| Key Specs | Klipsch R-51M | Jamo S 803 |
|---|
| Brand | Klipsch
United States · founded 1946 | Jamo
Denmark · founded 1966 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Tractrix Horn | 1" Soft-Dome |
|---|
| Woofer | 5.25" Copper-spun IMG | 5" Aluminized Polyfiber |
|---|
| Frequency response | 62-21k Hz | 57-26k Hz |
|---|
| Sensitivity | 93 dB | 87 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | Up to 85 watts | up to 80 watts |
|---|
| Weight | 5.00kg / 11lbs | 5.40kg / 11.9lbs |
|---|
| Dimensions (H x W x D) | 13.3" x 7.0" x 8.4"
338.0 x 178.0 x 215.0mm | 13.8" x 7.5" x 9.9"
353.0 x 191.0 x 252.0mm |
|---|
What size room are the Klipsch R-51M and Jamo S 803 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* |
Klipsch R-51M |
Jamo S 803 |
| 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 R-51M and S 803 are 2-way speakers.
Klipsch R-51MJamo S 803
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-51M |
Jamo S 803 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 5-inch
|
R-51M features a 1" Tractrix Horn Tweeter and 1 x 5.25" Copper-spun IMG Woofer with a Crossover frequency at 1660Hz. On the other hand, the S 803 features a 1" Soft-Dome Tweeter and 1 x 5" Aluminized Polyfiber Woofer.
Frequency Response
R-51M has a frequency range of 62-21k Hz whereas S 803 has a frequency range of 57-26k Hz. With a minimum frequency of 57Hz, the S 803 can go significantly deeper on the low side and provide stronger bass compared to 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
R-51M and S 803 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. R-51M sensitivity is rated at 93 dB and the S 803's is at 87 dB. This 6 dB difference makes the Klipsch R-51M a more sensitive speaker compared to Jamo S 803, 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.
R-51M can handle a max power of 85 watts RMS, whereas S 803 has a max power handling value of 80 watts RMS, 5 watts less than the R-51M.
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
R-51M features Post type posts and S 803 has a Post type posts. None of these speakers feature bi-amping/bi-wiring.
Klipsch R-51M's Single Gold Plated Binding Posts - 5-way terminals
Jamo S 803's Post terminals
Cabinet Type and Port Position
R-51M has a rear firing port whereas S 803 has a front firing ports. Jamo S 803's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Klipsch R-51M with its rear-firing 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 Klipsch R-51M's and Jamo S 803's external dimensions. Klipsch R-51M has external dimensions of 338.0 x 178.0 x 215.0mm (13.3 x 7.0 x 8.4inch) whereas Jamo S 803 has external dimensions of 353.0 x 191.0 x 252.0mm (13.8 x 7.5 x 9.9inch).
Jamo S 803 is clearly the larger of the two speakers. Its body is 13mm wider, 15mm taller and 37mm deeper than Klipsch R-51M.
Below you can see the front view size comparison of Klipsch R-51M and Jamo S 803 in scale.
Comparison image of Klipsch R-51M and Jamo S 803 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 Klipsch R-51M is approximately 382.7cm2 / 59.3inch2 and base area of the Jamo S 803 is approximately 481.3cm2 / 74.6inch2. The R-51M requires 20% less surface area than the S 803 which gives it a small advantage 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 Klipsch R-51M and Jamo S 803 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 Klipsch R-51M weighs 5.00kg / 11lbs and the Jamo S 803 weighs 5.40kg / 11.9lbs. This makes the S 803 8% heavier than the R-51M.
Here is a comparison of how R-51M and S 803's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Klipsch R-51M?
Here are the items that are included inside the box of R-51M:
- 2 Bookshelf loudspeakers
- 2 Grilles (installed)
- 8 Self-adhesive rubber feet
- Quick Setup Guide
- Important Safety Instructions
- Warranty Information
What's in the Box of Jamo S 803?
Here are the items that come with the S 803:
- 2 Bookshelf loudspeakers
- 2 Grilles
- User Manual
- Important Safety Instructions
- Warranty Information
 Max Input Power |
85 watts
vs
80 watts
|
Handle more power from your amplifier |
 Sensitivity |
93 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
5.25 inches
vs
5 inches
|
Larger woofer |
 Height |
338mm
vs
353mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
382cm2
vs
481cm2
|
Takes less floor space |
|
Low Frequency Response |
57 Hz
vs
62 Hz
|
Generates deeper bass |
 High Frequency Response |
26k Hz
vs
21k Hz
|
Generates higher frequency |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Price per pair* |
229USD
vs
359USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Klipsch Reference R-51M |
Jamo S 803 |
| Brand |
Klipsch |
Jamo |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
Up to 85 watts |
up to 80 watts |
| Sensitivity |
93 dB |
87 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
62-21k Hz |
57-26k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
5" |
| Woofer Composition |
Copper-spun IMG |
Aluminized Polyfiber |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Tractrix Horn |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1660Hz |
n/a |
| Firing Direction |
rear |
front |
Physical Specs |
|
|
| Height |
338.0mm (13.3") |
353.0mm (13.9") |
| Width |
178.0mm (7") |
191.0mm (7.5") |
| Depth |
215.0mm (8.5") |
252.0mm (9.9") |
| Weight |
5.00kg (11lbs) |
5.40kg (11.9lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
MDF/Vinyl |
| Available Colors |
Black |
Walnut, Black, White |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
24-28" |
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 | B | Jamo S 803 digs deeper - 57Hz against 62Hz. A subwoofer would even that out. |
| Amplifier needs | A | Klipsch R-51M is more sensitive (93dB vs 87dB), so it goes louder on the same amplifier. |
| Headroom | evenly matched | Similar power handling (85W vs 80W). |
| Size | depends | Klipsch R-51M is easier to place; Jamo S 803 is bigger, which usually goes with fuller bass. Your room decides. |
| Price | B | Jamo S 803 is cheaper - $229 against $359, about 36% less. |
A Klipsch R-51M B Jamo S 803
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. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 62Hz anyway, so judge these on the other rows instead. 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.