Dear ladies and gentlemen,
There is a lot of confusion and misconception about how the 'turbocharger' actually works. Please allow me to explain more clearly.
The turbocharger is a device that attaches to the rear ports of the subwoofer, makes a U-shape bend, and then fires forward. The turbo ports are housed in a rectangular box that rests on top of the subwoofer.
The idea behind this concept is relatively straightforward: to provide some of the benefits of both maximum output mode (= maximum available port flow area) and maximum extension mode (= lowest available tune).
Variable tuning solutions currently seen on the market from us and others work as follows: in order to reduce the tuning point (and therefore lower frequency response), the user is required to plug a port(s). The act of reducing port cross-sectional area while maintaining port length results in a lower effective tuning point for the subwoofer. While fairly effective in practice, one of the problems with this method is that port flow area is reduced by 33-50% each time that the tuning point is lowered.
The turbocharger is designed to allow one to effectively reduce tuning point without reducing available port flow area. By adding port length instead of keeping port length constant, a user will be able to reduce tuning point without needing to reduce port cross-sectional area. Please, please keep in mind that this is NOT the same thing as reducing tuning point without reducing
output. Based on fundamental laws of physics, efficiency lowers as tuning point is lowered, all else equal. This means that, no matter what method is used to achieve a lower effective tuning point (via port plugging method or via turbocharger), efficiency will lower and output over the common bass frequencies will go down. The main difference lies in the lower bass, where output tends to be boosted when lowering the tune. By keeping port flow area constant as tune lowers, one is able to further boost their low bass output versus plugging a port. There will be less port compression and less port turbulence-related noises, all else equal.
To conceptualize this and get a better understanding of why this concept is very fundamentally sound, think about performance differences in this comparison: a port-plugged VTF-2 MKII in 25Hz mode with one free 3" port, versus a turbocharged VTF-2 MKII in 25Hz mode with maximum available port flow area. It is easy to see why the latter would have a notable advantage in the lower bass where port contribution is significant.
There is more to tell about the upgrade option, but I am not ready to do so at this time, as I would like to keep it a surprise. My apologies
Hope this helps. We will try our best to swiftly provide new products in a tangible form.
Sincerely,