12 Inch Subwoofer Box – Volume, Port & Plans
The 12-inch subwoofer is the most popular choice — strong enough for serious bass but still small enough to fit in most trunks. Here are the volumes and tuning that work best.
Recommended volume
- Sealed box: 30–50 litres net. Tighter, more accurate bass, smaller size and more forgiving of volume errors.
- Ported box: 45–70 litres net. Clearly louder bass from the same amplifier, but it needs precise design.
High-excursion 12″ drivers are happiest in the upper half of these ranges. If the manufacturer lists a recommended volume, use it as the starting point and fine-tune for the music you listen to.
Port tuning and size
Most 12″ ported boxes are tuned between 30 and 35 Hz: around 32 Hz is a balanced daily setting, lower tuning favours deep hip-hop bass and higher tuning adds punch. Aim for a port area of about 250–450 cm² so the port stays quiet at high power — a slot is usually the easiest way to get there.
Example dimensions
A 55-litre net ported box for a single 12″ is roughly 700 × 400 × 380 mm outside in 18 mm MDF, while a 40-litre sealed box comes in around 550 × 380 × 350 mm.
Plans worldwide, built boxes in Bulgaria
Enter your 12″ driver in the free calculator to get the exact net volume, port length and MDF cut list. Anywhere in the world you can buy the downloadable plan and build the box yourself. Custom-built boxes are made and delivered only within Bulgaria.