subwoofer port holes

[danger boy]

i can't remember what tuning the port holes do on a subwoofer... if you plug one or both of them.. what does that do?

mine doesn't appear to hit as low.. but it seems to respond faster with the bass in music..

anyone shed some light on this please. tanks!

[Mick88]

i can't remember what tuning the port holes do on a subwoofer... if you plug one or both of them.. what does that do?

mine doesn't appear to hit as low.. but it seems to respond faster with the bass in music..

anyone shed some light on this please. tanks!

I have HSU VTF series with the two ports......here is the info from the manual.

Hope this helps.

Now that the basic setup is complete, it?s time for optimization. Mark down the current volume and crossover settings with a soft pencil
so you can go back to where you started.
Variable Tuning
If you don?t like the air shaking feeling of very deep bass, or if you often listen to extremely loud chest-thumping material that has less
deep bass, Maximum Output mode is for you.
You can switch over to Maximum Output mode when the system?s volume level is low or the subwoofer is OFF. There are two steps:
1) Grip and pull out the foam port plug that is inserted in one of the port holes on the back of the subwoofer, or remove the turbo.
2) Flip the BASS EXTENSION switch on the back of the subwoofer to the 2 ports open position.
In technical language, you will get about 4 dB of extra head-room so that bass can be played louder, at the expense of some deep bass
extension. In other words, the subwoofer has been transformed into a louder device with less deep bass.
Switching back is simply a matter of firmly re-inserting the port plug into one of the port holes or attaching a turbo and flipping the
switch back to ?1 port open? or ?1 port open or with turbo? position. Make sure that the switch setting is consistent with the port setting.
Using the wrong switch position at loud volume levels may damage your subwoofer and void the warranty

[TNRabbit]

Depends on the sub; some are tunable, others aren't. Which model do you have?

[rubin]

My 3 ported svs ultra13 is as follows: all open =20 hz 1,2, plugged =15hz,10hz. All plugged (sealed) is less than 10hz. Sealed gives the lowest frequency and lowest output.

[danger boy]

all good info guys.. i suspect most subs work pretty much the same in terms of plugging or unplugging the port holes..

when I plug both of mine.. the output level drops some.. and doesn't hit as low...

[GTB]

Another effect SOME subs are sensitive to is called "oil canning".

If you take a sub speaker made to work in a ported enclosure and put it in a sealed enclosure, run it hard, the cone could collapse. This is not a good thing.

Some speakers are vulnerable to this, others are not.

Greg