Subi 4.0

Subi 4.0 is Kinopoli's current bass system. It was built during the summer 2023 renovation to replace the TEH Subi. The old subwoofer was a ported enclosure of over 1,500 litres that had served as the platform for the back row since 2008. Instead of one giant, the bass now comes from four sealed subwoofers, one in each corner of the auditorium.

Specifications

• Four subwoofers, one in each corner of the auditorium
• Drivers: 21 inch
• Enclosures: sealed, about 350 litres each
• Replaced the 2008 TEH Subi

Why four instead of one

The old subwoofer was a single point at the back of the room. One subwoofer excites a room's standing waves the same way every time, and the difference is audible from one seat to the next: at a given frequency one row rumbles while another hears almost nothing. Four separate, symmetrically placed subwoofers excite the room's modes more evenly, which shrinks the differences between seats. In a small auditorium that matters, because every seat should sound as good as every other.

Direction you can hear

The biggest change in the listening experience is where the bass appears to come from. When it came from a single point under the back row, low frequencies came loose from the picture: a car exploding at the left edge of the screen seemed to explode behind you. Four subwoofers placed in the corners spread the low frequencies around the auditorium, so a bass hit stays in the direction it belongs to on screen instead of locating itself as one rumbling point in the back row. The spatial quality of a film's sound design therefore survives down into the lowest frequencies, which completes the auditorium's Dolby Atmos sound system.

The sealed enclosure brings a second benefit: compared with a ported one, the reproduction is tighter and more controlled. A bass hit starts and stops when it is supposed to, which suits cinema use well.

Kinopoli's main and centre speakers are described on the NuCau page. The full history of the theatre can be found on Kinopoli's own site.