Front view — side by side at true scale
AQuad S-4BCastle Avon 4
Click either cabinet to swap A ↔ B · Reference height: 955 mm (95.5 cm) · 1 mm = 0.59 px
| A | B | |
|---|---|---|
| Manufacturer | Quad | Castle |
| Model | Quad S-4 | Castle Avon 4 |
| Height | 870 mm | 955 mm |
| Width | 180 mm | 180 mm |
| Depth | 300 mm | 310 mm |
| Weight | 20.5 kg | 17.6 kg |
| Enclosure | passive-radiator | transmission-line |
| Drivers | 1× tweeter (ribbon), 1× 100 mm midrange (woven Kevlar cone), 2× 125 mm woofer (woven Kevlar cone) | 1× 130 mm woofer, 1× 115 mm midrange, 1× tweeter (ribbon) |
| Frequency — low | 44 Hz | 45 Hz |
| Frequency — high | 23000 Hz | 20000 Hz |
| Sensitivity | 88 dB | 89 dB |
| Impedance | 6 Ω | 8 Ω |
| Recommended amp | 40–200 W | 25–100 W |
| MAP (USD) | $1,499 / pair | — |
| Where to buy | Check availability ↗ | Check availability ↗ |
| Brand website | quad-hifi.co.uk ↗ | castle.uk.com ↗ |
| Product page | Open product page ↗ | Open product page ↗ |
Larger value highlighted in green. For low-frequency extension, lower Hz = greater bass reach, so the deeper side is highlighted.