Short answer: the AsciLab F6Bs. It ranks #20 of 222 bookshelf speakers by sound quality (rated 4.5/5); the XTZ Spirit 4 ranks #159 (rated 3.4/5).
The XTZ Spirit 4 is the deeper-bass choice. Stand-mount speakers with a waveguide tweeter, adjustable treble and port tuning, wide coverage and fairly deep bass. Its bass reaches about 40Hz before falling 10dB, against 50.1Hz for the AsciLab F6Bs. The catch: The third-party measurement is low confidence.
The AsciLab F6Bs is the more accurate pick. A slim, sealed bookshelf speaker that mounts flat on a wall bracket, with accurate sound and wide, even dispersion for a great price. Its measured preference score, a predictor of how neutral it sounds, is 5.24 against 4.18 for the XTZ Spirit 4. The tradeoff: AsciLab’s own site shows the F6Bs sold out, though it remains in stock through resellers like Audiophonics and Tested Audio.
Buy the AsciLab F6Bs. It is rated higher for sound quality than the XTZ Spirit 4.
Looking for alternatives? See the complete Passive Home rankings.
Stand-mount speakers with a waveguide tweeter, adjustable treble and port tuning, wide coverage and fairly deep bass.
A slim, sealed bookshelf speaker that mounts flat on a wall bracket, with accurate sound and wide, even dispersion for a great price.
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Specifications Side By Side
| XTZ Spirit 4 | AsciLab F6Bs | |
|---|---|---|
| Price | $477 per pair | €799 per pair |
| Ranked | #159 of 222 in Large Size Bookshelf Speakers | #20 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | about 40.0Hz (measured, Spinorama data) | 50.1Hz (measured, Audio Science Review) |
| Enclosure | 2-way passive, rear-ported | sealed |
| Drivers | 1” dome tweeter, 6.5” woofer | 1” aluminum dome tweeter with waveguide and phase plug, 6” fiber cone woofer |
| Dimensions | 13.8H x 7.5W x 10.6D in | 14.5”H x 8”W x 6.1”D (368 x 203 x 154 mm) |
| Weight | 17.9 lbs (8.1 kg) each | 12.3 lbs (5.6 kg) each |
| Sensitivity | 86dB | 85.2dB @ 2.83V/1m (measured, Audio Science Review) |
| Impedance | 4 ohms | 4 ohms nominal, 3.7 ohms minimum |
| Spinorama Preference Score | 4.18 | 5.24 |
| Spinorama Preference Score with Perfect Sub | 6.30 | 7.90 |
| Bass Extension (-3dB) | 42Hz (manufacturer specified) | 82.0Hz (measured, Audio Science Review) |
| DIY Kit | No | No |
| Crossover Frequency | - | 1kHz |
| Mounting | - | VESA 100 wall mount compatible |
| Warranty | - | 2 years |
| Country | - | South Korea |
| Maximum SPL | - | 100dB full bandwidth, 102dB above 100Hz (manufacturer specified) |
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