Front view — side by side at true scale
APolk Reserve R100BCastle Richmond IV
Click either cabinet to swap A ↔ B · Reference height: 324 mm (32.4 cm) · 1 mm = 1.73 px
| A | B | |
|---|---|---|
| Manufacturer | Polk | Castle |
| Model | Polk Reserve R100 | Castle Richmond IV |
| Height | 324 mm | 305 mm |
| Width | 167 mm | 190 mm |
| Depth | 260 mm | 262 mm |
| Weight | 5.5 kg | 6.3 kg |
| Enclosure | bass-reflex-rear | bass-reflex-rear |
| Drivers | 1× 25 mm tweeter (Pinnacle ring radiator), 1× 133 mm mid-bass (Turbine cone) | 1× 150 mm mid-bass, 1× 32 mm tweeter (soft dome) |
| Frequency — low | 58 Hz | 58 Hz |
| Frequency — high | 39000 Hz | 22000 Hz |
| Sensitivity | 86 dB | 87 dB |
| Impedance | 4 Ω | 8 Ω |
| Recommended amp | 30–150 W | 25–100 W |
| MAP (USD) | $699 / pair | $760 / pair |
| Where to buy | Check availability ↗ | Check availability ↗ |
| Brand website | polkaudio.com ↗ | 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.