The Boulder MK-III specifications

• 2 x 220mm (8.5") Crystal Membrane Woofer
• 1 x Dual Concentric 130mm (5") X-Jet Mid Range and 50kHz Folded Ribbon Tweeter
• Sealed Baltic Birch 18mm (.75") Plywood Cabinet
• Corian 30mm (1.2") Front Baffle Design
• 2 x Class D 300 watt amplifiers including their own dedicated power supply for the 2 x 220mm woofer.
• 2 x Discrete A/B Amplifiers by EsotericAudio Research for the Coaxial X-Jet mid/tweeter
• Balanced XLR Input
• Frequency response - 30Hz-38kHz +/-3dB
• Cabinet Dimensions - 390mm D x 268mm W x 614mm H
• 15.4" D x 10.5" W x 24.2" H
• Weight - 28.8 Kg

High Frequency Cut/Boost Section

Boulder MK-III HF & MID Switches

These two graphs show the performance of the HF 10kHz EQ Shelf switch, Flat and cut and boost of 2.5dB. The other shows the performance of the MID cut/boost switch.