Short answer: the KEF LSX II LT for better sound quality, the Audioengine HD4 for the lower price. The KEF LSX II LT ranks #27 of 58 powered bookshelf speakers at $600. The Audioengine HD4 ranks #52 at $429, $171 cheaper.
What the KEF LSX II LT offers: Coaxial (Uni-Q-style) driver keeps the tweeter centered in the midrange, giving wide and consistent dispersion both horizontally and vertically (about ±60° each) - a wide sweet spot for multiple seats or positions. The KEF Connect app provides genuinely useful DSP control: desk/wall boundary compensation, adjustable bass contour (standard/less/extra), treble trim, and subwoofer integration, letting you tune the sound to wherever it’s placed. Distortion at a moderate 86dB looks good for the speaker’s compact size. Tonal profile stays consistent from 0° to 30° off-axis, so side-seat listeners hear essentially the same balance as someone centered. Extensive connectivity for its size: HDMI, USB, optical, sub output, plus Wi-Fi/Bluetooth. Clearly outperformed the reviewer’s soundbars, including ones bundled with their own subwoofers, as a TV audio replacement. Watch for: Small drivers mean it’s SPL-limited: bass compression kicks in around 88-92dB/1m per speaker, and multitone distortion crosses the reviewer’s 3% threshold around 96dB - not intended for loud or large-room duty. F3 of 55Hz and F10 of 46Hz mean it loses much of its bass by around 50Hz; a subwoofer (controllable through the same app) is needed for real low end. Diffraction dips appear around 4-5kHz and again near 8kHz, likely tied to the tweeter housing or surround, giving a mild reduction in treble attack and sibilance. A possible port or enclosure resonance shows up around 800Hz in the rear-radiation measurements, though the reviewer wasn’t certain of the exact cause or whether it’s audible. No analog input on this LT variant, so a turntable can’t be connected directly - only the pricier standard LSX II model includes one.
What the Audioengine HD4 offers: Watch for: Not a great sounding speaker for the high price.
Buy the KEF LSX II LT if sound quality matters more than the price. Buy the Audioengine HD4 if the price matters more than sound quality.
If sound quality matters at all to you, skip the Audioengine HD4. It ranks near the bottom of the 58 powered bookshelf speakers, so look higher up the list instead.
Specifications Side By Side
| KEF LSX II LT | Audioengine HD4 | |
|---|---|---|
| Price | $600.00 | $429.00 |
| Ranked | #27 of 58 in Medium Size Powered Bookshelf Speakers | #52 of 58 in Medium Size Powered Bookshelf Speakers |
| Dimensions | 9.5"H x 6.1"W x 7.1"D (241.3 x 154.9 x 180.3 mm) | 9"H x 5.5"W x 6.5"D (228.6 x 139.7 x 165.1 mm) |
| Inputs | Wifi, USB-C, HDMI, Optical, Bluetooth | Bluetooth, Aux, RCA Input |
| Outputs | RCA Subwoofer | RCA Output |
| Drivers | 115mm (4.5in.) magnesium/aluminium alloy cone woofer, 19mm (0.75in.) aluminium dome tweeter | 4" (102mm) woofer |
| Weight | 15 lbs / 6.8 kg | 7.3 lbs / 3.3 kg |
| App | No | No |
| Bluetooth | No | No |
| EQ | No | No |
| Output Power | 100w RMS Per Speaker | 50w RMS Per Speaker |
| Bass Extension (-3dB) | 55Hz (measured, Erin’s Audio Corner) | - |
| Bass Extension (-10dB) | 46Hz (measured, Erin’s Audio Corner) | - |
| Sensitivity | 84dB (measured at 0.3V/1m, Erin’s Audio Corner) | - |
| Frequency Response | - | 60 Hz-20 kHz (-3dB) (Manufacturer specified) |
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- IK Multimedia iLoud MTM MKII vs Dayton Audio M4
- Dayton Audio M4 vs Audioengine HD6
- Dayton Audio M4 vs Vanatoo Transparent One Encore Plus
- Neumann KH80 DSP vs Audioengine HD4
- Edifier S2000MKIII vs Audioengine HD4
Prices on this page were last checked August 24, 2026 at 6:53 AM 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
KEF LSX II LT: $600.00 Amazon eBay
Pros: Coaxial (Uni-Q-style) driver keeps the tweeter centered in the midrange, giving wide and consistent dispersion both horizontally and vertically (about ±60° each) - a wide sweet spot for multiple seats or positions. The KEF Connect app provides genuinely useful DSP control: desk/wall boundary compensation, adjustable bass contour (standard/less/extra), treble trim, and subwoofer integration, letting you tune the sound to wherever it’s placed. Distortion at a moderate 86dB looks good for the speaker’s compact size. Tonal profile stays consistent from 0° to 30° off-axis, so side-seat listeners hear essentially the same balance as someone centered. Extensive connectivity for its size: HDMI, USB, optical, sub output, plus Wi-Fi/Bluetooth. Clearly outperformed the reviewer’s soundbars, including ones bundled with their own subwoofers, as a TV audio replacement.
Cons: Small drivers mean it’s SPL-limited: bass compression kicks in around 88-92dB/1m per speaker, and multitone distortion crosses the reviewer’s 3% threshold around 96dB - not intended for loud or large-room duty. F3 of 55Hz and F10 of 46Hz mean it loses much of its bass by around 50Hz; a subwoofer (controllable through the same app) is needed for real low end. Diffraction dips appear around 4-5kHz and again near 8kHz, likely tied to the tweeter housing or surround, giving a mild reduction in treble attack and sibilance. A possible port or enclosure resonance shows up around 800Hz in the rear-radiation measurements, though the reviewer wasn’t certain of the exact cause or whether it’s audible. No analog input on this LT variant, so a turntable can’t be connected directly - only the pricier standard LSX II model includes one.
Full KEF LSX II LT review and specifications →
| App | No |
|---|---|
| Bass Extension (-10dB) | 46Hz (measured, Erin's Audio Corner) |
| Bass Extension (-3dB) | 55Hz (measured, Erin's Audio Corner) |
| Bluetooth | No |
| Dimensions | 9.5"H x 6.1"W x 7.1"D (241.3 x 154.9 x 180.3 mm) |
| Drivers | 115mm (4.5in.) magnesium/aluminium alloy cone woofer, 19mm (0.75in.) aluminium dome tweeter |
| EQ | No |
| Inputs | Wifi, USB-C, HDMI, Optical, Bluetooth |
| Output Power | 100w RMS Per Speaker |
| Outputs | RCA Subwoofer |
| Sensitivity | 84dB (measured at 0.3V/1m, Erin's Audio Corner) |
| Weight | 15 lbs / 6.8 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- KEF LSX II LT vs Dayton Audio M4
- KEF LSX II LT vs Edifier S2000MKIII
- KEF LSX II LT vs KRK Classic 5
- KEF LSX II LT vs Edifier MR4
- KEF LSX II LT vs JBL 705P
- KEF LSX II LT vs Vanatoo Transparent One Encore Plus
- KEF LSX II LT vs IK Multimedia iLoud MTM
- KEF LSX II LT vs Topping MA4
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Audioengine HD4: $429.00 Amazon eBay
Cons: Not a great sounding speaker for the high price.
Full Audioengine HD4 review and specifications →
| App | No |
|---|---|
| Bluetooth | 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) |
| Inputs | Bluetooth, Aux, RCA Input |
| Output Power | 50w RMS Per Speaker |
| Outputs | RCA Output |
| Weight | 7.3 lbs / 3.3 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Audioengine HD4 vs Edifier S1000MKII
- Audioengine HD4 vs Klipsch The Fives
- Audioengine HD4 vs Edifier R1280DB
- Audioengine HD4 vs KRK Classic 5
- Audioengine HD4 vs Edifier S2000MKIII
- Audioengine HD4 vs Dayton Audio M4
- Audioengine HD4 vs IK Multimedia iLoud MTM MKII
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