Short answer: the Audioengine HD4. It ranks #86 of 105 powered bookshelf speakers by sound quality, rated 3.2/5, at $429. The Klipsch Reference R-40PM ranks #105, rated 1.5/5, at $349.99, $79.01 cheaper, a saving that is not big enough to make up the sound-quality gap.
The Audioengine HD4 is the better-sounding pick. Compact powered cabinets, analog input options and RCA output can simplify a desktop stereo system. The catch: The compact cabinets suit close desktop listening rather than a large-room system.
The case for the Klipsch Reference R-40PM: Compact powered stereo monitors featuring a 70W total RMS Class-D amplifier driving 4-inch spun-copper TCP woofers and 1-inch aluminum LTS tweeters on edge-to-edge 90x90 Tractrix horns. The tradeoff: Natural acoustic low-frequency extension rolls off below 60Hz from the small 4-inch woofer, making a companion subwoofer necessary for full bass weight in home theater or music listening.
Buy the Audioengine HD4. It is rated higher for sound quality, and saving $79.01 with the Klipsch Reference R-40PM does not make up for the sound-quality gap.
About the ratings: the Klipsch Reference R-40PM’s rating is estimated from measured siblings and predecessors rather than its own measurements, with a likely range of 1.3 to 1.7, so this verdict could change once it is measured.
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Specifications Side By Side
| Audioengine HD4 | Klipsch Reference R-40PM | |
|---|---|---|
| Price | $429.00 per pair | $349.99 per pair |
| Ranked | #86 of 105 in Medium Size Powered Bookshelf Speakers | #105 of 105 in Medium Size Powered Bookshelf Speakers Estimated |
| Dimensions | 9”H x 5.5”W x 6.5”D (228.6 x 139.7 x 165.1 mm) | 11.7” x 5.7” x 8.5” (298 x 146 x 216 mm) |
| Frequency Response | 60 Hz-20 kHz (-3dB) (Manufacturer specified) | 60Hz - 20kHz (Manufacturer specified) |
| Inputs | Bluetooth, Aux, RCA Input | Bluetooth, Phono/Line RCA, 3.5mm Aux, USB, Optical |
| Outputs | RCA variable output (subwoofer) | - |
| Weight | 7.3 lbs (3.3 kg) | 15 lbs (6.8 kg) |
| Drivers | 4” (102mm) woofer | 1” aluminum LTS tweeter on Tractrix horn, 4” spun-copper TCP woofer |
| App | No | - |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD | - |
| EQ | No | - |
| Amplifier Power | 50w RMS Per Speaker | 70W total (140W peak) |
| Subwoofer Output | Yes | Yes |
| XLR Input | No | - |
| RCA Input | Yes | Yes (switchable phono preamp) |
| TRS Input | No | - |
| Optical Input | No | Yes |
| Coaxial Input | No | - |
| USB Input | No | Yes (USB-B audio) |
| HDMI Input | No | - |
| AES Input | No | - |
| Aux Input | Yes | Yes |
| Maximum SPL | - | 100dB |
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- Genelec 8320A vs Audioengine HD4
Prices on this page were last checked October 11, 2026 at 4:59 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Speakers In Full
Audioengine HD4: $429.00 per pair Amazon eBay
Same family: the Audioengine HD3 (smaller bookshelf, rated 3.2/5), the Audioengine HD6 (larger bookshelf, ranked higher, rated 3.3/5) and the Audioengine HD5 (larger bookshelf, ranked lower, estimated 3.2/5).
Pros: Compact powered cabinets, analog input options and RCA output can simplify a desktop stereo system. Its modest footprint is useful where larger studio monitors are impractical.
Cons: The compact cabinets suit close desktop listening rather than a large-room system. A separate subwoofer adds cost and space if deeper bass is a priority.
Full Audioengine HD4 review and specifications →
| Released | 2016 (10 years ago) |
|---|---|
| AES Input | No |
| Amplifier Power | 50w RMS Per Speaker |
| App | No |
| Aux Input | Yes |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD |
| Coaxial Input | No |
| Dimensions | 9”H x 5.5”W x 6.5”D (228.6 x 139.7 x 165.1 mm) |
| Drivers | 4” (102mm) woofer |
| EQ | No |
| Frequency Response | 60 Hz-20 kHz (-3dB) (Manufacturer specified) |
| HDMI Input | No |
| Inputs | Bluetooth, Aux, RCA Input |
| Optical Input | No |
| Outputs | RCA variable output (subwoofer) |
| RCA Input | Yes |
| Subwoofer Output | Yes |
| TRS Input | No |
| USB Input | No |
| Weight | 7.3 lbs (3.3 kg) |
| XLR Input | No |
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Klipsch Reference R-40PM: $349.99 per pair Estimated Amazon eBay
Same family: the Klipsch Reference R-50PM (larger bookshelf, estimated 1.8/5).
Pros: Compact powered stereo monitors featuring a 70W total RMS Class-D amplifier driving 4-inch spun-copper TCP woofers and 1-inch aluminum LTS tweeters on edge-to-edge 90x90 Tractrix horns. Low-end reproduction benefits from dynamic bass EQ, extending bass perception down to 60Hz. Versatile connectivity includes a built-in phono preamp with ground terminal, 3.5mm analog, optical digital, USB audio (supporting up to 24-bit/96kHz), Bluetooth, and a dedicated RCA subwoofer output.
Cons: Natural acoustic low-frequency extension rolls off below 60Hz from the small 4-inch woofer, making a companion subwoofer necessary for full bass weight in home theater or music listening. Awaiting independent Klippel NFS Spinorama linearity data.
Full Klipsch Reference R-40PM review and specifications →
| Released | 2023 (3 years ago) |
|---|---|
| Amplifier Power | 70W total (140W peak) |
| Aux Input | Yes |
| Bluetooth | Yes |
| Dimensions | 11.7” x 5.7” x 8.5” (298 x 146 x 216 mm) |
| Drivers | 1” aluminum LTS tweeter on Tractrix horn, 4” spun-copper TCP woofer |
| Frequency Response | 60Hz - 20kHz (Manufacturer specified) |
| Inputs | Bluetooth, Phono/Line RCA, 3.5mm Aux, USB, Optical |
| Maximum SPL | 100dB |
| Optical Input | Yes |
| RCA Input | Yes (switchable phono preamp) |
| Subwoofer Output | Yes |
| USB Input | Yes (USB-B audio) |
| Weight | 15 lbs (6.8 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons