VTF-3HO turbo

There is an interesting discussion on the AVSForum on an image of the new HSU VTF-3HO (high output) sub with a turbo charger attached. The effect of the turbo charger is to lengthen the ports and lower the tuning frequency without having to plug a port which was necessary in the older models. Leaving both ports open and lowering the tuning frequency results in a supposed 6db increase in output near the tuning frequency. Apparently there will be a turbo charger for the HSU-VTF3 MKII also.
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