The subs are two stock Ruby 18 in ported cabinets from the Roxy Theater, stacked in the middle of the bottom row between the scoops. They play the same bass band as the scoops and reach lower, from 40 Hz. We run them gently because the drivers are old and one cone has been repaired.
Subs and scoops share the bass band and the bass master fader, so they should hit their limiters at the same moment. Then turning up the bass takes both to their limits together, and neither runs out first.
The gain sits before the limiter, so it never moves a threshold. It only decides when the signal reaches it.
Check it: pink noise into the bass input; both outputs' limiter lights should come on at the same fader position.
If either limit moves, move the sub gain by the same amount. For example, if the scoop gain comes down 2 dB to +6, the sub gain comes down to +1. The same goes for a limiter: lower the scoop limiter 2 dB and the sub gain comes down 2 dB too.
The ports are tuned to about 39-40 Hz (measured 2026-10-19: close-miked, the port is 18 dB louder than the cone at 39.5 Hz). Below tuning a ported box unloads and the cone travel climbs fast, so the steep high-pass sits right at the tuning. No T/S data exists for these drivers, so their excursion cannot be modelled: start at 40 Hz and move it up (45, then 50) only if the cones flap or bottom out at the limiter.