Specs for the Silver 10s (the full range driver on the top:
Impedance: 8 ohm
• Power: 25 – 50 W
• Frequency response: Fu – 20k Hz
• Fs: 28.3 Hz
• Sd: 346.36 cm²
• Qms: 11.173
• Qes: 0.321
• Qts: 0.312
• Sensitivity: 98.6 dB (2.83V/1m)
• Vas: 333.43 litre
Specs for the W-15 (sub-bass driver on the bottom):
• Related power – Maximum power: 100W – 150W
• Nominal Inpendance Z: 8+8 Ohm
• Fs: 27.6Hz
• Qms: 14.6
• Vas: 656 L
• Cms: 0.6 mm/N
• Mms: 95 g
• Rms: 0.81 kg/S
• Xmax: 15 mm(peak)
• Xmech: 20 mm(peak)
• Sd: 855 sqcm
• Vd: 2.05L (p-p)
• Qes: 0.97
• Re: 3.12 ohm
• Le: 0.04 mH
• Z: 6.7 ohm
• Bl: 6.1 T/m
• Pe: 100W (cont.)
• Qts: 0.79
• Sensitivity (2.83V / 1m): 91.3 dB (single coil)
• Sensitivity (2.83V / 1m): 95.6 dB (dual coil)
Depending on how you wire the sub-bass driver, it can go from 4, 8, or 16 ohms. You can use one or two coils either in series or in parallel for a different result.