View Full Version : Concerns with a dual port box (differant tunes)

06-07-2006, 06:58 AM
Iamamp3pimp and i are gonna collaborate and build a box for this hybrid beast for fun.... thing is we want to do 2 ports, one tuned for balls to the wall SPL, and one tuned to 25Hz for the murderus lows this thing does...and simply put a port plug/plate over the one not being used....

here's the problem.... how would the port volume of the COVERED PORT effect the internal volume of the enclosure for the other side that's being used....

should we incorportate the port volume of the unused side(covered) into the internal volume for the side that being used(not covered)?

also how would the shape of that port NOT being used (covered) effect the sound resonance inside the box??

also if we did incorporate the unused(covered) side into the design for one side, that would ultimately effect the internal volume for when we use the other side....?

help a brotha out lol

06-07-2006, 11:48 AM
Depending on how you do it, if you just cover the opening to a port, it's volume in the box will only be the volume of the plastic, if you use a port plug (think ear plug) you will need to add the volume of air in the port it takes up.

06-07-2006, 11:55 AM
Your port plug should be an internal piece. Not just a cover for the port opening. Design it to fill up any volume in the larger port, so there will be no air around the port plug while it is inside the larger port.

Displacement will remain the same this way. Deduct the larger ports volume. And it will not effect air flow inside the box.

:fyi: unless this is for a HT setup 25hz will just reduce your overall output. Low end extension in vehicle will not be any greater tunning that low.

06-07-2006, 02:28 PM
the driver has spacers between the basket and magnet giving it room for more throw....this thing did 140 on the TL at 29Hz (his avaitar) :)