On the occasion of the Graspop Metal Meeting festival (17-19 June), Belgian rental company KO-sound launched its brand new proprietary S18 subwoofer.
“We absolutely needed to expand our subs inventory,” explains René Kuipers, managing director of KO-sound. “We were actually very happy with the performance of our existing subs (SA AB18), but the release of some new interesting high power 18” drivers made us rethink the situation.”
Kuipers modelled the existing sub in software, and discovered that with a new driver and modifications in the cabinet design, he could improve the LF performance drastically. “The result is that the AES-rated power is increased to 1,600W (+60%), the linear excursion of the driver increased to 13.5mm (+40%) and the tuning of the whole system could be brought down by 8Hz. For the same amount of power, we now have 6dB more output @ 25Hz,” he enthuses. “We compared the S18 to a top model 2×18” of a renowned manufacturer, and the output of the single 18” S18 was very close to this double 18” model.”
At Graspop, KO-sound had eight S18 subs in use on the Metaldome stage (pictured). “The speakers are all handcrafted and production takes quite some time. But we plan to upgrade our stock to 36 units by the end of the year. They will serve as replacement for the SA AB18 speakers who have, by then, between five and ten years of operation,” Kuipers concludes.
KO-sound is a regular supplier for the Graspop festival, this year with headliners Black Sabbath, and thrash metal heroes Slayer, Megadeth and Anthrax, before an audience of 140,000. René Kuipers and his team provided kit for the Metaldome stage (32x Adamson S10 as main speaker system), the Marquee (24x L-Acoustics K2, 24x SB28) and The Jupiler Stage (16x K2, 12x SB28).