Short answer: the Audioengine HD4 for better sound quality, the Fluid Audio FX50 V2 for the lower price. The Audioengine HD4 ranks #58 of 67 powered bookshelf speakers, rated 3.2/5, at $429. The Fluid Audio FX50 V2 ranks #64, rated 2.7/5, at $149, $280 cheaper.
The case for the Fluid Audio FX50 V2: The coaxial geometry and mounting provisions allow flexible physical orientation, while balanced inputs and boundary controls suit a compact studio installation. The catch: Scores of 1.80 standalone and 4.42 with an ideal subwoofer indicate poor native tonal accuracy.
The case for the Audioengine HD4: Compact powered cabinets, analog input options and RCA output can simplify a desktop stereo system. Watch for: The compact cabinets suit close desktop listening rather than a large-room system.
Buy the Fluid Audio FX50 V2 if the price matters more than sound quality. Buy the Audioengine HD4 if sound quality matters more than the price.
Looking for alternatives? See the complete Powered Home rankings.
Specifications Side By Side
| Fluid Audio FX50 V2 | Audioengine HD4 | |
|---|---|---|
| Price | $298 per pair | $429.00 per pair |
| Ranked | #64 of 67 in Medium Size Powered Bookshelf Speakers | #58 of 67 in Medium Size Powered Bookshelf Speakers |
| Enclosure | Active coaxial, front-ported | - |
| Drivers | 1-inch silk tweeter coaxially mounted in 5-inch paper woofer | 4" (102mm) woofer |
| Frequency Response | 49Hz-22kHz +/-2dB | 60 Hz-20 kHz (-3dB) (Manufacturer specified) |
| Amplifier Power | 90W each | 50w RMS Per Speaker |
| Maximum SPL | 110dB | - |
| Inputs | XLR/TRS and RCA | Bluetooth, Aux, RCA Input |
| Dimensions | 9.2H x 6.9W x 9.1D in | 9"H x 5.5"W x 6.5"D (228.6 x 139.7 x 165.1 mm) |
| Weight | 8.4 lbs (3.8 kg) each | 7.3 lbs (3.3 kg) |
| Spinorama Preference Score | 1.80 | - |
| Spinorama Preference Score with Perfect Sub | 4.42 | - |
| XLR Input | Yes | No |
| RCA Input | Yes | Yes |
| TRS Input | Yes | No |
| Optical Input | No | No |
| Coaxial Input | No | No |
| USB Input | No | No |
| HDMI Input | No | No |
| AES Input | No | No |
| Aux Input | No | Yes |
| Bluetooth | No | Yes |
| Outputs | - | RCA variable output (subwoofer) |
| App | - | No |
| Bluetooth Codecs | - | SBC, AAC, aptX, aptX HD |
| EQ | - | No |
| Subwoofer Output | - | Yes |
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Prices on this page were last checked September 23, 2026 at 11:24 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
Fluid Audio FX50 V2: $298 per pair Fluid Audio eBay
Pros: The coaxial geometry and mounting provisions allow flexible physical orientation, while balanced inputs and boundary controls suit a compact studio installation. Bass reaches -3dB around 67Hz in ASR’s selected measurement.
Cons: Scores of 1.80 standalone and 4.42 with an ideal subwoofer indicate poor native tonal accuracy. Listening-window and predicted-room narrow-band deviations are both around 0.80, showing irregular sound for both the listener and room reflections. Coaxial construction does not guarantee smooth dispersion or neutral reproduction, and correction features should not be credited as a proven fix.
Full Fluid Audio FX50 V2 review and specifications →
| AES Input | No |
|---|---|
| Amplifier Power | 90W each |
| Aux Input | No |
| Bluetooth | No |
| Coaxial Input | No |
| Dimensions | 9.2H x 6.9W x 9.1D in |
| Drivers | 1-inch silk tweeter coaxially mounted in 5-inch paper woofer |
| Enclosure | Active coaxial, front-ported |
| Frequency Response | 49Hz-22kHz +/-2dB |
| HDMI Input | No |
| Inputs | XLR/TRS and RCA |
| Maximum SPL | 110dB |
| Optical Input | No |
| RCA Input | Yes |
| Spinorama Preference Score | 1.80 |
| Spinorama Preference Score with Perfect Sub | 4.42 |
| TRS Input | Yes |
| USB Input | No |
| Weight | 8.4 lbs (3.8 kg) each |
| XLR Input | Yes |
- Links
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Audioengine HD4: $429.00 per pair Amazon eBay
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 →
| 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 |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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