Short answer: the Cambridge Audio L/R S. It ranks #4 of 48 powered bookshelf speakers by sound quality (rated 4.4/5) at $549 and is still sold new; the Kanto YU4 ranks #23 (rated 3.3/5) and is discontinued, so it is only an option used. The Kanto YU4’s replacement, the Kanto YU4 G2, is rated 3.6/5 at $449.99.
The L/R S is the much more accurate small pair. Erin’s measurements show a very neutral on-axis response within about 2.5dB from 80Hz to 20kHz, wide horizontal coverage and bass to 57Hz before falling 3dB. It has optical, RCA, USB-C, aptX HD, app room settings and a subwoofer output. Its clean output tops out around 86dB, so it suits a desk or small room.
The YU4 is a discontinued, feature-rich pair with weak measurements. It has phono, optical and Bluetooth inputs, a remote and a subwoofer output. Audio Science Review found bass falling 3dB around 86Hz, a 4.2dB midrange span and a preference score of 2.89, so it needs a subwoofer and still is not neutral.
Buy the Cambridge Audio L/R S. It is rated higher for sound quality and still sold new, while the Kanto YU4 is discontinued.
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Specifications Side By Side
| Cambridge Audio L/R S | Kanto YU4 | |
|---|---|---|
| Price | $549.00 per pair | $479.99 per pair Discontinued |
| Ranked | #4 of 48 in Small Size Powered Bookshelf Speakers | #23 of 48 in Small Size Powered Bookshelf Speakers |
| Bass Extension (-3dB) | 57Hz (measured, Erin’s Audio Corner) | - |
| Bass Extension (-10dB) | 50Hz (measured, Erin’s Audio Corner) | - |
| Drivers | 21mm aluminum dome tweeter, 3” long-throw woofer | 1” silk-dome tweeter, 4” Kevlar woofer |
| Frequency Response | 55Hz - 24kHz (±3dB, manufacturer specified) | 60Hz-20kHz |
| Amplifier Power | 100W total (50W to woofer, 50W to tweeter, per speaker) | 70W RMS / 140W peak per pair |
| Inputs | RCA, optical digital, USB-C | Bluetooth, optical, RCA/phono, 3.5mm |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD | SBC, aptX |
| App | Yes | - |
| DSP | Yes, room size, wall distance, and reflective surface correction; desktop-placement and near-wall/free-space switches | - |
| Dimensions | 5.3” (134 mm) W x 226mm H x 180mm D (each) | 8.7H x 5.5W x 7.5D in |
| Weight | 6.6 lbs (3.0kg) primary speaker, 5.7 lbs (2.6kg) secondary speaker | 6.8 lbs (3.1 kg) powered / 5.5 lbs (2.5 kg) passive |
| Subwoofer Output | Yes | Yes |
| Outputs | Subwoofer, wired speaker-to-speaker link | Subwoofer |
| XLR Input | No | No |
| RCA Input | Yes | Yes |
| TRS Input | No | No |
| Optical Input | Yes | Yes |
| Coaxial Input | No | No |
| USB Input | Yes | No |
| HDMI Input | No | No |
| AES Input | No | No |
| Aux Input | No | Yes |
| Bluetooth | Yes | Yes |
| Spinorama Preference Score | 5.08 | 2.89 |
| Spinorama Preference Score with Perfect Sub | 7.72 | 5.83 |
| Bluetooth Version | 5.1 | 4.0 |
| Enclosure | - | Powered 2-way, rear-ported |
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