The KEF Q2ds is a three-way, dipole surround speaker designed for multi-channel home theatre systems, part of KEF's Q series from the early 2000s. It is highly regarded for providing an immersive and powerful surround sound experience.
Key Specifications
According to product information from KEF and retailers like iEar', the KEF Q2ds speakers have the following specifications:

• Design: Three-way dipole surround
• Drive Units: 2 x 165 mm Uni-Q® array, 1 x 130 mm (5¼”) down-firing LF (Low Frequency) driver
• Frequency Response (±3dB): 80 Hz – 27 kHz
• Crossover Frequencies: 220 Hz and 3 kHz
• Amplifier Requirements: 15 – 120 W
• Sensitivity (2.83V/1m): 91 dB
• Maximum Output: 111 dB
• Impedance: 8 Ohms