The simple upgrading equipment rather than porting the trunk to cabin is a flawed and poor response.
The bottom line is the 6x9s need to be removed from the rear deck of a car when subs are in the trunk and the seats are up.
The reason is the pressure (both ways) involved with the subs. When the sub extends and presureizes the trunk, the 6x9s are forced to extends also. Same is true when the sub pulls back.
This actually causes the 6x9 to over extend. If power is applied to the speaker while this is happening it causes issues.
Now if your port the trunk and do so with say, 2 3" ports through the arm rest as mentioned- then you are creating a bandpass box. The same issues I mentioned earlier will still be a factor- besides the weird tuning this will create. The reason behind this is you are actually going to use ports that have an influence on the subs. The reason removing the 6x9s wont have an impact on the subs is because it will actually create a tuning point well above where the subs operate.
Now that Ive sunk so much time into this response I hope its crystal clear to AleroDrime and the others who commented.
