Onkyo SC-750 (1984–1986)

Documentation on the Onkyo SC-750 is thin. No original brochure or period review has surfaced in the archive. What the record does show is a serious, well-built Japanese floorstander from the mid-1980s. The SC-750 was a three-way design with a 250mm woofer and 140mm midrange, both using Onkyo's patented Deltaolefin cone material (a three-layer composite: a foamed inner layer with high internal loss, sandwiched between two outer layers of reinforced polyolefin), plus a 25mm magnesium dome tweeter. The woofer basket was cast aluminum - a step up from the stamped steel used on the lesser SC-601. Impedance is rated at 6 ohms, weight comes to 20 kg, and dimensions are 335 × 600 × 325 mm (with the grille cover). Production ran from 1984 to 1986, and the speakers were made in Japan.

The one substantial first-hand account comes from a Russian owner on the drive2.ru forum. He bought his pair from a German audiophile in like-new condition, stands included. His verdict on the tweeter: the magnesium dome "handles its duty excellently, highs are very juicy." He also notes the bass is firmer than on the later SC-960, which he found softer. Commenters on the same thread praised the looks and sound, though one flagged the known Onkyo weakness, foam surround rot. The original surrounds on this pair were "barely hanging on," and the midrange drivers were affected too. That is a common failure across the SC series. The owner replaced them himself, and repair kits for the SC-750's woofer and midrange surrounds are still sold today.

The drive2.ru author states the SC-750 sat a class above the SC-601. A German classifieds listing cites the original price at roughly 900 DM per speaker. Current asking prices vary widely, with one listing at €750 and another at 390 €. No auction history is documented, so there is no firm market value.