Honestly accroding to Ilkka's measuements, there is very minimal variation in output, compression and THD (if any at all) between the maximum extension mode and the turbocharger. Nevertheless, with turbo port resonnance at 120 Hz make me feel bad. This indicates the subwoofer is not limited by port area to begin with, thus making not beneficial the addition of turbocharger to inscrease an already good port area. Maybe the Turbo would work better for smaller area ports, but not this one.
Last point..... I trust Ilkka's measurements
