View Full Version : making port longer..reduces tuning requency or increases it?

06-21-2008, 01:15 PM
I had a box ready to go tuned to 37 hz, bu last minute i made the port 4 or 5 inches longer...would this make it tuned higher or lower?

06-21-2008, 01:17 PM
it would tune lower but your loosing airspace inside the box. unless you accounted for it when building the box.

06-21-2008, 01:44 PM
Its gonna drop it.

06-22-2008, 03:06 AM
if i had it tuned to 37hz and i extended the slot port from about 23" to 30" is that going to give a significant drop?

06-22-2008, 03:47 AM
you need to recalculate it... it depends on your box volume and port displacement

PV Audio
06-22-2008, 03:48 AM
The question can only be answered in a general sense. In many cases, making the port longer can raise the tuning frequency, because the extra airspace taken up on the inside counteracts the effect of the longer vent.

06-22-2008, 03:48 AM
Increasing port length also decreases box volume. Therefore, you need to account for both changes in order to determine the new specs.

06-22-2008, 07:49 PM
so if im not exactly sure what my tuning freq is whats a good place to set my SSF at? maybe 28 ?

06-23-2008, 01:59 PM
Well what are the box dimensions? Measure it, it'll help much more than just the general question.