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Klipsch R-51PM Review

With the technological development in the audio field and the gradual popularization of high-definition digital music on mobile phones, both audiophiles and ordinary music lovers for many years must admit that listening to music with mobile phones connected to audio has become the mainstream of the public.Klipsch R-51PM Bluetooth Active Bookshelf Speaker is the product of upgrading existing products in combination with current listening habits.

klipsch r-51pm

In addition to having Klipsch’s consistently high appearance, and applying Klipsch’s latest acoustic technology, including Tractrix horn, IMG diaphragm mid-bass unit, etc., to ensure excellent sound performance.

Besides, rich functions such as wireless Bluetooth, USB DAC digital input, and built-in phono preamplifier are also scarce in products at the same level.

American Klipsch is one of the originators of designing and producing horn speakers. Since its establishment in 1941, through constant innovation in horn speakers, it has created several excellent products that shocked the industry.

The founder, Paul W. Klipsch, holds 23 individual patents. The Klipschorn Emperor makes it possible for people to hear such a dynamic, delicate and emotional live sound in their own homes for the first time. It thoroughly demonstrates the four design standards of Klipsch speakers: high sensitivity, wide dynamic range, low distortion, and smooth frequency response. At the same time, Klipsch has achieved a unique position in the horn speaker industry.

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Klipsch R-51PM comes from the Reference series with great attention. It is an upgraded version of the classic R-15PM. The PM in the model stands for Powered Monitors (active monitor speakers).


Compared with R-15PM, it has a larger horn opening, and the improved radiation angle and bandwidth can provide better coverage angle at lower frequencies, which is helpful for the extension of medium and high frequencies. Besides, the overhanging part of the mid-bass unit and the diaphragm have also been improved accordingly.

Klipsch R-51PM, this model is only available in black, the overall design retains the retro charm but adds today’s fashion sense. The angular cabinet is very American style. The magnetic dust cover is easy to install and remove. The centre of the bottom of the dust cover is a bronze Klipsch logo. The Klipsch R-51PM has left, and right channels and the right channel speaker has an LED indicator in the upper right corner of the mid-bass unit. As the basic configuration of the active speaker, it is convenient for the user to observe whether it is powered on. Of course, it can also be turned off through the remote control Indicator light.

The Horn and the Woofer

With the dust cover removed, the first impression of Klipsch’s patented 90 ° × 90 ° Tractrix horn and the iconic bronze mid-bass unit is the atmosphere. The treble and mid-bass units are all screwed around. This design is standard in professional monitor speakers. Paired with the horn is a 1-inch aluminium LTS (Linear Travel Suspension) tweeter. This tweeter was once the hallmark of R’s flagship Palladium series. Linear Travel Suspension system makes the unit more efficient and can effectively reduce high-frequency distortion to obtain more details.

klipsch r-51pm horn

The mid-bass unit is a 5.25-inch cone-shaped copper IMG diaphragm. IMG stands for Injection Molded Graphite. The injection-moulded graphite (IMG) woofer has extremely light material properties. With the smallest cone vibration and the lowest acoustic distortion, an amazing low-frequency response is quickly delivered. The hanging edge of the mid-bass unit uses a high-damping tree pulp diaphragm, and the excellent elasticity makes the mid-low frequency dynamic range broader and more sense.

klipsch r-51pm woofer

The power amplifier and DAC circuit are integrated into the right channel speaker, using a low-noise amplifier custom-designed by Klipsch top engineers, using a speaker cable to connect the left and right channel speakers. Therefore, the back panel of the left channel speaker will be relatively simple. The rear guide hole design can effectively improve its low-frequency energy.

Klipsch R-51PM has a wealth of functions, as can be seen from the back panel of the right channel speaker. The large knob in the upper centre of the panel can be turned to adjust the volume, and press to select the signal source. This knob also needs to be pressed when pairing with the mobile phone’s Bluetooth for the first time.

klipsch r-51pm back panel

The Input Interfaces

The Micro USB interface on the left is used for firmware upgrade, which is also different from the previous generation R15PM. The right side of the knob is the ground terminal, which is used with the vinyl record player to eliminate the current sound.

The left side of the input panel of the signal source is the digital input area, which are USB audio input and optical fibre interface. For users who use R-51PM as a desktop speaker, it is estimated that the USB connection to the computer is the most used scenario. The use of optical fibre interfaces is more extensive, such as CD players with optical fibre output, televisions and so on.

klipsch r-51pm input

The right side is the input and output of analog signals. R-51PM is a bookshelf speaker. Although the 5.5-inch mid-woofer can meet most of the listening needs, you can also connect an external subwoofer if you encounter a large room area or high-frequency requirements solve.

Next to it is the more common 3.5mm AUX audio input and RCA input interface. The most significant feature of this speaker is the built-in phono preamplifier, which can be adjusted to the PHONO mode. At this moment, you can connect the vinyl record player to feel that unique analog charm.

The Klipsch R-51PM is equipped with remote control, and its compact shape provides a comfortable grip. Some special functions can only be adjusted through remote control, for example, by adjusting the sensitivity of low frequency to meet the listening needs of different users. And the remote control has a reset button to restore the factory settings quickly.

Remote Control Fnctions

When used by connecting to a Bluetooth device, the remote control can control the playback and pause of music, which is much more convenient than operating on a Bluetooth device. Standard functions such as volume control, channel selection, LED light control, mute, switch on and off can also be managed through the remote control, which significantly improves the ease of use of R-51PM. Most users who use high-fidelity audio to listen to music are essentially for relaxing. Convenient operation is its most basic prerequisite.

klipsch r-51pm back

Klipsch R-51PM has built-in phono preamplifier, which can be easily matched with a vinyl record player. Besides, R-51PM black wood grain, horn treble highlights the retro style. No matter where in the home, such a suit can enhance the form of the room.

Which CD Player to Use?

As the most used collocation solution in the field of the audiophile, the CD can intuitively show the sound quality of a speaker. The choice here is Demon’s new 600NE CD player. The most recommended is this CD player.

There are two main reasons. First of all, the price and the function match. Because the R-51PM has a built-in power amplifier and has a USB DAC decoding, then the CD player can have the most basic functions as long as the quality passes. The second reason is that people often say “buy new not buy old.” The Demon 600NE CD player is a new model that was just launched at the end of 19. Through AL32 high-precision processing technology, the sampling rate and bit rate are increased in the digital signal so that The sound is more delicate and full, and the overall quality has improved a lot compared to the old one.

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Although the Klipsch R-51PM Bluetooth active speaker positioning is entry-level, it applies the latest acoustic technology of Klipsch. It has high competitiveness in terms of sound performance compared to products of the same price. Built-in high-efficiency power amplifier with Bluetooth function, no need to purchase other devices, you can enjoy beautiful music by connecting your mobile phone. The unique phono preamplifier can match the vinyl record player in the simplest way.

Klipsch R-51PM Specs

  • SYSTEM DESCRIPTION:Powered Monitor (pair)
  • DYNAMIC BASS EXTENSION: 49Hz @ 35% Volume
  • MAX OUTPUT: 107.3 dB
  • TOTAL SYSTEM POWER: 120W Total System Power (140W Peak),60W per channel cont. @ <%1 THD
  • HIGH FREQUENCY DRIVER: 1” (2.5cm) Aluminum diaphragm compression driver mated to 90° x 90° square Tractrix horn
  • LOW FREQUENCY DRIVER: 5.25” (13.3cm) copper spun magnetically shielded IMG woofer
  • CROSSOVER FREQUENCY: 1663 Hz (Passive)
  • ENCLOSURE TYPE: Bass-reflex via rear-firing port
  • INPUTS:Bluetooth, wireless technology, Phono/Line analog (with switch and ground screw terminal), 3.5mm analog mini jack, USB digital, Optical digital
  • OUTPUTS: Single RCA line level output for connection to subwoofer
  • HEIGHT, WIDTH, DEPTH: 13.3” (33.8 cm), 7” (17.78 cm), 9.12” (23.16 cm)
  • WEIGHT: 10.6 lbs (4.8 kg)
  • FINISH: Black
  • VOLTAGE: 100V-240V 50/60Hz internal power supply with region specific power cords