In this review, we will be comparing RP-600M II and R-51M, two Passive Bookshelf speakers by Klipsch
Let's have a brief look at the main features
of Klipsch RP-600M II and Klipsch R-51M first before getting into our more
detailed comparison.
Klipsch RP-600M II Key Specs
- 2-way Design
- 1" Hybrid Tractrix Horn Tweeter
- 6.5" Cerametallic cone Woofer
- 44-25k Hz Frequency Response
- 94.5 dB Sensitivity
- Impedance: 8ohms
- Power Range:up to 100watts
- Weight:8.20kg
- Dimensions (H x W x D): 402.0" x 8" x 13-1/16"( 402.0 x 204.0 x 332.0mm )
Klipsch R-51M Key Specs
- 2-way Design
- 1" Tractrix Horn Tweeter
- 5.25" Copper-spun IMG Woofer
- 62-21k Hz Frequency Response
- 93 dB Sensitivity
- Impedance: 8ohms
- Power Range:Up to 85watts
- Weight:5.00kg
- Dimensions (H x W x D): 338.0" x 7.0" x 8.4"( 338.0 x 178.0 x 215.0mm )
What size room are the Klipsch RP-600M II 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* |
Klipsch RP-600M II |
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.)
In the following sections, we will get into more detail in order to better understand how the Klipsch RP-600M II and Klipsch R-51M compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
Both RP-600M II and R-51M are 2-way speakers.
| Driver |
Klipsch RP-600M II |
Klipsch R-51M |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 5.25-inch
|
RP-600M II features a 1" titanium Hybrid Tractrix Horn Tweeter and 1 x 6.5" Cerametallic cone Woofer with a Crossover frequency at 1500 Hz. 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
RP-600M II has a frequency range of 44-25k Hz whereas R-51M has a frequency range of 62-21k Hz. With a minimum frequency of 44Hz, the RP-600M II can go significantly deeper on the low side and provide stronger bass compared to the R-51M's min frequency of 62Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
High Frequency
Bookshelf Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
RP-600M II and R-51M have the same Impedance of 8 ohms but where they differ is the sensitivity levels. RP-600M II sensitivity is rated at 94.5 dB and the R-51M's is at 93 dB. This 1 dB difference makes the Klipsch RP-600M II a more sensitive speaker compared to Klipsch R-51M, 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. While using
an amplifier within this range ensures the nominal performance , inputting a power that is higher than the
max wattage can result in a damaged speaker.
RP-600M II can handle a max power of 100 watts RMS from the amp the whereas R-51M has a max power handling value of 85 watts RMS, 15 watts less than the RP-600M II.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
RP-600M II features Binding post posts which make bi-amping or bi-wiring possible. R-51M has a Single Gold Plated Binding Posts - 5-way which doesn't feature bi-amping/bi-wiring.
Klipsch RP-600M II's Binding post terminals allows Bi-amping or bi-wiring
Klipsch R-51M's Single Gold Plated Binding Posts - 5-way terminals
Cabinet Type and Port Position
Both RP-600M II 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
Size of a speaker can sometimes become 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 RP-600M II's and Klipsch R-51M's external dimensions. Klipsch RP-600M II has external dimensions of 402.0 x 204.0 x 332.0mm ( 15-13/16 x 8 x 13-1/16inch) 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 RP-600M II is clearly the larger of the two speakers. Its body is 26mm wider, 64mm taller and 117mm deeper than Klipsch R-51M.
Below you can see the front view size comparison of Klipsch RP-600M II and Klipsch R-51M in scale.
Comparison image of Klipsch RP-600M II 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 Klipsch RP-600M II is approximately 677.3cm2 / 105.0inch2 and base area of the Klipsch R-51M is approximately 382.7cm2 / 59.3inch2. The RP-600M II requires 77% more surface area than the R-51M which gives it a small disadvantage on placement in tight spaces.
Here is an 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 RP-600M II and Klipsch R-51M on a Media Console