VTF3.3 turbo - extension vs output

[benchlegs]

Peter:
I know Hsu directs turbo users to have there mode set to maximum extension with both ports open. What will happen with both ports open at maximum output mode?
Thanks
Jack

[Splotto]

Peter:
I know Hsu directs turbo users to have there mode set to maximum extension with both ports open. What will happen with both ports open at maximum output mode?
Thanks
Jack

The entire universe will come to a complete halt and life as we know it will cease to exist.

Splotto

[Pete_Hsu]

Welcome to the forum Jack!

If one runs the VTF-3 Mk3 turbo with maximum output (25Hz) mode set on the amp, then they will get an overdamped response that starts rolling off earlier than it normally would in 18Hz mode. It is safe to run in this configuration. However, I would strongly advise against running the VTF-3 Mk3 with both ports open (no turbo) and 18Hz set on the amplifier, as this could damage the subwoofer due to lack of electronic protection in the 18-22Hz range as the driver unloads below port tuning.