Tube Port : Area & Displacement
Square Port : Area & Displacement
Port Area Recalculator
Speaker Displacement
Some helpful Infos :
Actually it
is not necessary to use decimals. But if you are kind of person who
loves being that exact you must use the point (.) to separate the
decimals.
It is obviously, that the calculated speaker displacement is not ultraprecise! But it is exact enough for our purpose.
Hollywood Energetic Aeroport AP16: 189 cm²
Hollywood Energetic Aeroport AP11: 85 cm²
Hollywood Energetic Aeroport AP 8 : 44 cm²
It is obviously, that the calculated speaker displacement is not ultraprecise! But it is exact enough for our purpose.
Hollywood Energetic Aeroport AP16: 189 cm²
Hollywood Energetic Aeroport AP11: 85 cm²
Hollywood Energetic Aeroport AP 8 : 44 cm²
While you are building up and tuning your subwoofer system you should use a trial-port. This one should be longer than calculated by your simulationsoftware or mentioned in the guide of the manufacturer. While you are tuning the system you can find the best sounding length by shortening the port in aprox 2 cm steps. The final tuning in the car does not only result out of what you do with the port. Also the position of the port in the enclosure and surrounding areas in the trunk have notable impact. The load-through provision in the rear seats is also uncalcubale but has much influence.
Please do NOT use any carpet or cloth within the port. It might look good, but it has bad effects on the air that wants to vibrate exactly in the port. It is very good to round up the ends of the port as the Hollywood Energetic Aeroports do. The moving air mass in the port thanks it to you by producing very less noise.
If you plan to put those stupid figures with long hair in the port, you can also put carpet inside. There will be no help for you...
You can also prevent the port itself from resonating. The techniques are the same as you know from building enclosures or damping doors. You can use energy absorbing material such as the Hollywood Roadkill or you can raise the stiffness of the port by bracing. But remember, your activities have to find place outside the port, NOT in the port.
To have your subwoofer system playing clear and acurate you must follow the idea of an acoustical real "dead" workplace, with just the moving cone. At least, this is essential for every speaker. Subwoofer have many possibilities to behave like a brat - just doing what the parents do not want them to do.
First of all, the enclosure itself might be not rigid enough. In most cases you can raise the stiffness by implementing braces, that connect in best way four walls. Or at least stiff up the baffle against the back-wall. If you have your own gas-station you can build up enclosures with wallthickness of many centimetres, but bracing will have same effect with less weight!
Now, when your enclosure is stiff and rigid to save you against bomb attacks, you can put it in your trunk. What now happens is that the superstiff system moves completely in the trunk - with every beat. So, it is also necessary to fix it in the car.
Take the time to improve your woofersystem, it pays!