In this review, we will be comparing R-51PM and A1 Wireless, two Powered Bookshelf speakers from Klipsch and Audioengine. Being Powered speakers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them.
Let's have a brief look at the main features
of Klipsch R-51PM and Audioengine A1 Wireless first before getting into our more
detailed comparison.
| Key Specs | Klipsch R-51PM | Audioengine A1 Wireless |
|---|
| Brand | Klipsch
United States · founded 1946 | Audioengine
United States · founded 2005 |
|---|
| Design | 2-way | 2-way |
|---|
| Built-in amplifier | 120-watt RMS (240-watt peak) | 30-watt RMS |
|---|
| Tweeter | 1.0" Tractrix Horn | 0.75" Soft-Dome |
|---|
| Woofer | 5.25" Copper-spun IMG | 2.75" Aramid Fiber |
|---|
| Frequency response | 68-21k Hz | 65-22k Hz |
|---|
| Max depth / sample rate | 24-bit / 96 kHz | 16-bit / 48 kHz |
|---|
| Bluetooth | Built-in 3.0 | Built-in 5.0 |
|---|
| Weight | 4.80kg / 10.6lbs | 1.10kg / 2.4lbs |
|---|
| Dimensions (H x W x D) | 13" x 7.0625" x 10.25"
330.2 x 179.4 x 260.3mm | 6.25" x 4.1875" x 7.125"
158.8 x 106.4 x 181.0mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both R-51PM and A1 Wireless are 2-way speakers.
Klipsch R-51PMAudioengine A1 Wireless
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-51PM |
Audioengine A1 Wireless |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1.0-inch
|
0.75-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5.25-inch
|
1 x 2.75-inch
|
R-51PM features a 1.0" Aluminum LTS Tractrix Horn Tweeter and 1 x 5.25" Copper-spun IMG Woofer with a Crossover frequency at 1663Hz. On the other hand, the A1 Wireless features a 0.75" Silk Soft-Dome Tweeter and 1 x 2.75" Aramid Fiber Woofer.
Frequency Response
R-51PM has a frequency range of 68-21k Hz whereas A1 Wireless has a frequency range of 65-22k Hz. With a minimum frequency of 65Hz, the A1 Wireless can go slightly deeper then the R-51PM's min frequency of 68Hz.
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.
Cabinet Type and Port Position
R-51PM has a rear firing port whereas A1 Wireless has a front firing ports. Audioengine A1 Wireless's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Klipsch R-51PM 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-51PM's and Audioengine A1 Wireless's external dimensions. Klipsch R-51PM has external dimensions of 330.2 x 179.4 x 260.3mm (13 x 7.0625 x 10.25inch) whereas Audioengine A1 Wireless has external dimensions of 158.8 x 106.4 x 181.0mm (6.25 x 4.1875 x 7.125inch).
Klipsch R-51PM is clearly the larger of the two speakers. Its body is 73mm wider, 171.4mm taller and 79.3mm deeper than Audioengine A1 Wireless.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Klipsch R-51PM needs about 142% more floor or shelf area. Klipsch R-51PM is 79mm deeper, so it stands that much further out from the wall. Klipsch R-51PM is 171mm taller.
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-51PM is approximately 467.0cm2 / 72.4inch2 and base area of the Audioengine A1 Wireless is approximately 192.6cm2 / 29.9inch2. The R-51PM requires 142% more surface area than the A1 Wireless which gives it a small disadvantage on placement in tight spaces.
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-51PM weighs 4.80kg / 10.6lbs and the Audioengine A1 Wireless weighs 1.10kg / 2.4lbs. This makes the R-51PM 336% heavier than the A1 Wireless.
Here is a comparison of how R-51PM and A1 Wireless's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Klipsch R-51PM?
Here are the items that are included inside the box of R-51PM:
- Powered speaker (right)
- Passive speaker (left)
- 2 Grilles
- 68-inch AC power cord
- Remote control
- 2
What's in the Box of Audioengine A1 Wireless?
Here are the items that come with the A1 Wireless:
- Wireless powered left speaker
- Passive right speaker
- 6-feet AC power cord
- 6.5-feet Length of 18 gauge speaker wire
- 6.5-feet Stereo minijack-to-RCA cable
- 6-feet Stereo minijack cable
- Quick Start Guide
- Audioengine product brochure
 Woofer Size |
5.25 inches
vs
2.75 inches
|
Larger woofer |
 Handheld Remote |
Yes
vs
No
|
Control the speaker by the included RC |
 USB Port |
USB-B
vs
No
|
USB port adds flexibility |
 RCA Connection |
Yes
vs
No
|
Connection via RCA input |
 Phono Input |
Yes
vs
No
|
Connect your turntable directly |
 Digital Input |
Optical
vs
No
|
Connect digital inputs directly |
|
Low Frequency Response |
65 Hz
vs
68 Hz
|
Generates deeper bass |
 High Frequency Response |
22k Hz
vs
21k Hz
|
Generates higher frequency |
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Height |
158mm
vs
330mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
192cm2
vs
467cm2
|
Takes less floor space |
 Price per pair* |
199USD
vs
599USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Klipsch Reference R-51PM |
Audioengine A1 Wireless |
| Brand |
Klipsch |
Audioengine |
| Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
| Frequency Response |
68-21k Hz |
65-22k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
120-watt RMS |
30-watt RMS |
| Watts Peak (Max) |
240-watt RMS |
n/a |
| Max Bit Depth |
24-bit |
16-bit |
| Max Sample Rate |
96 kHz |
48 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
5.25" |
2.75" |
| Woofer Composition |
Copper-spun IMG |
Aramid Fiber |
| Tweeter Size |
1.0" |
0.75" |
| Tweeter Type |
Tractrix Horn |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1663Hz |
n/a |
| Firing Direction |
rear |
front |
Physical Specs |
|
|
| Height |
330.2mm (13") |
158.8mm (6.3") |
| Width |
179.4mm (7.1") |
106.4mm (4.2") |
| Depth |
260.3mm (10.2") |
181.0mm (7.1") |
| Weight |
4.80kg (10.6lbs) |
1.10kg (2.4lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm, RCA |
3.5mm |
| USB Port |
USB-B |
No |
| Phone Input |
Yes |
No |
| Subwoofer Output |
Wired |
Wired |
| Digital Input |
Optical |
No |
| HDMI Input |
No |
No |
| Headphone Jack |
No |
No |
| Ethernet Port |
No |
No |
Other |
|
|
| Parts Warranty |
1 Year |
3 Years |
| Labor Warranty |
1 Year |
3 Years |
These sit in different price classes - Klipsch R-51PM costs roughly 3x what Audioengine A1 Wireless does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | B | Audioengine A1 Wireless digs deeper - 65Hz against 68Hz. A subwoofer would even that out. |
| Built-in power | A | Klipsch R-51PM has the bigger amplifier (120W vs 30W RMS). |
| Connections | A | Klipsch R-51PM adds phono and digital inputs. |
| Size | depends | Audioengine A1 Wireless is easier to place; Klipsch R-51PM is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Klipsch R-51PM: a sub output; Audioengine A1 Wireless: a sub output. |
| Price | B | Audioengine A1 Wireless is cheaper - $199 against $599, about 67% less; arguably a different class. |
A Klipsch R-51PM B Audioengine A1 Wireless
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?
Klipsch R-51PM is ahead, but only on 1 of the measured areas, and it costs about 3x the price. That is a lot of money for a narrow margin on paper - Audioengine A1 Wireless looks like the sensible buy unless something else about the Klipsch R-51PM appeals to you. In a large or open-plan room, Klipsch R-51PM has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Audioengine A1 Wireless is the easier speaker to get right. Think about the whole system, not just the speakers: the roughly $400 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
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.