Klipsch Reference R-51M is a 2-way Passive Bass Reflex Bookshelf speaker by Klipsch. It features a 1" Tractrix Horn Tweeter and 1 x 5.25" Copper-spun IMG Woofer. The speaker has a frequency range of 62-21k Hz and a sensitivity of 93 dB. Klipsch R-51M has an MSRP of 359$ per pair but can often be found around 199$ per pair.
What size of room is the Klipsch R-51M speaker good for?
The size of the room that you are planning to use the Klipsch R-51M is an important decision factor. Here we have evaluated its suitability to various size of environments considering its size and max power parameters:
| Listening Environment |
Suitability |
| Near-field | Average |
| Small Room | Good |
| Mid-size Room | Average |
| Large Room | Poor |
| Very Large Room | Bad |
What are the speakers in Klipsch's Reference (R) Series?
R-51M is a member of Klipsch's Reference (R) series of Passive speakers. Below you can see the main specs of these speakers.
Klipsch Reference (R) Series Speakers
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What is the Frequency Response of the Klipsch R-51M speaker?
Klipsch R-51M has a Frequency response range of 62-21k Hz at ±3dB and Power Range of 85 watts. At a minimum frequency of 62 Hz, it is hard to expect a strong bass response from R-51M so depending on your intended use, using a subwoofer will significantly help to widen the response range.
To focus on the subwoofers that are in a similar price range with Klipsch R-51M, check the Powered Subwoofers under $500. Alternatively, find the Full list of Powered Subwoofers regardless from the price.
Here we have a comparison of how R-51M's Low and High frequency values compared with the average, max and min Low and High frequency values in its class.
Low Frequency
Bookshelf Speakers
High Frequency
Bookshelf Speakers
Among the speakers in our database with a max MSRP price of 500$ (Pair), these are the 5 Passive Bookshelf speakers that have the deeper bass levels than the Klipsch R-51M's 62Hz:
What is the Crossover frequency of Klipsch R-51M?
Crossover frequency of the R-51M is set to 1660Hz. This is the threshold frequency where the higher frequency signals over this level are sent to the tweeter and the lower frequency signals are sent to the woofer by the crossover component.
What is the Impedance and Sensitivity of the Klipsch R-51M? Is it an easy to drive speaker?
Klipsch R-51M's nominal impedance level is
8 ohms and has a sensitivity of
93 dB.
Sensitivity
Bookshelf Speakers
8 Ohms is pretty much the standard nominal impedance amongst stereo speakers and amplifiers so Klipsch Reference R-51M is not considered a difficult to drive speaker from nominal Impedance perspective.
Sensitivity
93dB of Klipsch Reference R-51M is considered a high sensitivity compared to average stereo speaker which makes R-51M an easy to drive from Sensitivity perspective. If you are planning to power your speaker with a Tube amp which are generally very low power, the Klipsch R-51M will be a good choice.
Check our Integrated Amplifiers page to find an amplifier to pair with the Klipsch R-51M.
Input Type
R-51M features Single Gold Plated Binding Posts - 5-way type connectors. Bi-amping and Bi-wiring is not possible.
Klipsch R-51M Back View
Klipsch R-51M External Dimensions and Weight
Klipsch R-51M has external dimensions of (Height x Width x Depth) 13.3 x 7.0 x 8.4inch (338.0 x 178.0 x 215.0mm ).
Base Surface Area
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base area of Klipsch R-51M is approximately 382.7cm2 / 59.3inch2.
To have a better perspective on the real life size of Klipsch R-51M, let's compare it with a standard size Compact Disc which has a diameter of 4.7inch (120mm).
Klipsch R-51M Speaker Size Compared to a Compact Disc
Here we place the Klipsch R-51M virtually next to a standard width amplifier and turntable on a BDI Octave Media Cabinet to get a better idea about the size.
Klipsch R-51M Speaker next to an amplifier and turntable
WeightThe Klipsch R-51M weighs 5.00kg / 11lbs (per piece). Here is a comparison of how R-51M's weight compared with the average, max and min weights in its class.
Weight
All Bookshelf Speakers
Weight
Bookshelf Speakers under $500
Cabinet type and Materials
Klipsch R-51M has a
Bass Reflex type cabinet and MDF/Wood-grain vinyl finish. Bass Reflex type loudspeakers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed designs.
Speaker Feet
Klipsch R-51M comes with
8 Self-adhesive rubber feet which you can use to secure your loudspeaker on the surface that you are putting on. It is always recommended to use some kind of feet under all types of speakers. Besides limiting the movement of the speakers, it also compensates for non-flat surfaces and limits the contact surface area of the speaker. Rubber based feet also help isolating the vibrations within certain frequency ranges.
Port Position
Klipsch R-51M is a rear-firing port speaker so you have to make sure you leave enough space between the back of the speaker and wall or bookshelf so that it has room to breathe.
Available colors
Klipsch R-51M is available in Black.
Wall Mounting
R-51M doesn't sport any built-in mounting bracket so you need an external structure to mount on walls.
Does the Klipsch R-51M come with a Grille?
R-51M comes with magnetic grilles in black color choices. The purpose of the grille is to protect the delicate driver elements from external impacts while still allowing the sound pass as clearly as possible. Since the included grille of the R-51M magnetic type, it is very easy to put it on and off.
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
User's Manual
For more information about how to setup, use and maintain the Klipsch Reference R-51M, use the direct link below to download the official manual document:
Download User Manual for Klipsch R-51M
Official Brochure
Here is a link to download the official brochure for the Klipsch Reference R-51M speaker:
Official Brochure for Klipsch R-51M
Official Product Page
Official manufacturer's product page for the Klipsch Reference R-51M speaker can be found below:
Official Product Page for Klipsch R-51M
Warranty
5 Years of parts warranty and 5 Years of labor warranty is generally provided by the manufacturer.