The Onkyo D-33 X is a bookshelf loudspeaker that was manufactured from 1988 to 1989 in Japan. These speakers are notable for their unique construction materials, featuring 10-inch woofers made of pure carbon fiber, providing deep bass response. The midrange driver measures 4 inches and is constructed from Onkyo's patented Deltaolefin material, which enhances sound clarity by minimizing resonance. The 1-inch tweeter is made of titanium, a material commonly used in high-end audio equipment, allowing for a clear and soft high frequency output. The speakers utilize a three-way, three-speaker air suspension system, enabling a playback frequency range from 35 Hz to 45 kHz. The D-33 X has a maximum input of 150W and an impedance rating of 6 ohms, with an output sound pressure level of 91 dB/W/m. The cabinet has an internal volume of 26.5 liters and dimensions of 295 mm in width, 530 mm in height, and 269 mm in depth, with a total weight of 11.5 kg. This model was originally priced at approximately 700 DM per piece, contributing to its value within the audio community as a rare collectible.
