Featured 2 12's in a 2018 Mustang GT.

[Airflow_Concepts]

No way those 4" ports (12.56in2) are sufficient. On his power... even 2ohm? I advocate for 2x the port area but if using external Pvc watch for those plumbers problems like >150hz resonance that resonates <150hz. Make it solid.
Its a real thing with long external Pvc ports in my exp.

So do you think adding another 4-in port to each chamber will increase the output.

 

[shredder1 10+ year member]

So do you think adding another 4-in port to each chamber will increase the output.

It would but certainly make those ports prohibitively long. Even turning the center chamber divider into a window brace and going with a single 6" is more port than dual 4"... Not much but some. Round ports at times make things difficult, with set port area it's hard to nail the best area for best output.

Right now your at about 8in2^ft3, it just depends on the power and subs capability

 

[Airflow_Concepts]

Okay added another 4-in port to each chamber and definitely suffered in output as far as volume and low frequency response. I do know that it is a slightly undersized recommended volume for each subwoofer. Definitely got a sniff of the coils after adding the second port to each chamber. It's literally a third louder and lower with just the one 4-in port at roughly 11 to 13 inches in length. I do know and understand that the ports need to be substantially longer when adding more port area, but at this point it seems like the enclosure volume is the inefficient factoring in the equation. Good news is that the subs do not seem to be mechanically maxed out but the ear test does acknowledge that adding more power at a certain point Just gets muddy and ineffective for output.

 

[Airflow_Concepts]

New Enclosure

 

[Airflow_Concepts]

Video of new setup.

 

[Jimi77 Premium Member]

I'm not into SPL systems, but that is a pretty cool trick with the towels.

 

[BP1Fanatic]

Nice ride!